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Turbo choice
#132154
14/06/2006 19:08
14/06/2006 19:08
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Joined: Dec 2005
Posts: 17,367
Staffordshire
Nigel
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Staffordshire
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having spoken with both Craig and Mano at Turbo dynamics, I have a turbo dilemma 1) GT28R with larger compressor wheel 2) GT28RS with standard 0.64 3) GT28RS with standard turbine, but larger compressor wheel In my ignorance of fine detail on turbos, is No3 just the GT28RS with the 0.86 compressor? This is all based on the fact that my existing GT28R is still making increasing power at the redline (although the boost has always dropped of by then) I will be able to run high boost (forged pistons) and I DON'T want too much lag. Current setup gives me decent boost by about 3,000 rpm So, I'm looking for 3,000 - 3,200 spoolup (remember I have yet to fit a straight induction mod, and I'll certainly be having C&B cams). I also want boost all the way to the redline (although I accept that a bit of drop-off is safe) Whilst I'm looking for 330 - 340 bhp now, I may want more later. My current preference is no. 3, as I can learn to live with 200-300rpm more lag, and the cams and induction will pull out anything above this Any thoughts from the usual bunch of turbo-nutters? 
![[Linked Image]](https://i.imgur.com/19K9lau.jpg)
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Re: Turbo choice
#132155
14/06/2006 19:19
14/06/2006 19:19
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Anonymous
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Anonymous
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I'd go for number 3 Nigel, possibly 2 - but not 1. Looking at the unichip thread graphs it does not look like the R units spool up that much quicker than a 0.64 RS, and they dont develop the same power. the turbo of choice is definately an RS if you'r going to boost it up and really get an RS going, which you'll be able to do!
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Re: Turbo choice
#132157
14/06/2006 19:38
14/06/2006 19:38
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Anonymous
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Anonymous
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not a turbo nutter but reacently done alot of calling around on turbos etc (spoke to mano also) my oppinion is 2, because you will still be able to run enough boost and power to kil your engine and have quicker spool up. @340/350bhp i dont think you are pushing the 0.64 too much and i am confident you will have more to come if you want it. just my oppinion, probably boll**ks but hey 
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Re: Turbo choice
#132158
14/06/2006 19:56
14/06/2006 19:56
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Anonymous
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Anonymous
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Quote:
Whilst I'm looking for 330 - 340 bhp now, I may want more later.
Sounds like you really want a 2.4l+ conversion. It's less than another Ferrari .
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Re: Turbo choice
#132159
14/06/2006 20:04
14/06/2006 20:04
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Anonymous
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Anonymous
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I've got option 1 and there doesn't seem to be any differences with that and a standard R.
If I had to buy another turbo it'd certainly be option 2.
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Re: Turbo choice
#132160
14/06/2006 23:20
14/06/2006 23:20
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Anonymous
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Anonymous
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id vote for number 2 as well nigel as while i know some are running the bigger turbo i think its a bit laggier. An ideal compromise would be the .64 housing 28rs with the same exhaust side as the 28r but i have a feelign that would be very pricey from TD if they made it up. What have they suggested as you could use their advice and then buy it from ATP, which is a bit sly but the money saved would go towards forged bits surely 
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Re: Turbo choice
#132161
14/06/2006 23:31
14/06/2006 23:31
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Anonymous
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Anonymous
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Nigel, I think you may struggle to get spool-up less than 3500rpm with the (0.86) GT28rs. However its a very smooth turbo, which makes the car feel more normally aspirated than turbocharged if that's your thing, and it will allow more headroom if you really want to start pushing things boost wise once you have your forged pistons. The only slight caveat is that with the standard injectors 350bhp is going to be right at the limit with this turbo, maybe a bit more like flea's results but not much. So if you are going to push the boost further, and you can run 1.6 even 1.8 midrange with this turbo, then you are going to run into this issue. So that means larger injectors and then probably either the latest Unichip (Fergies results not withstanding) or Motec/DTA etc Another issue with 350 bhp + is the concern about the strength of the Coupe rods if you are not going to upgrade those as well. so you see there's a few obstacles to runnign more than 350-360 bhp which you will almsot certainyl get running a GT28rs with those mods I would have thought. So,.. if you are not going to go over the 360bhp barrier, and keep her more reliable, then probably the GT28 rs (0.64) will get you up to that limit, be able to keep your injectors and give you 3000rpm spool up....hmmm decisions decisions!! regards Joe ps remap on Monday next week, so will have a clearer idea then
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Re: Turbo choice
#132162
15/06/2006 03:13
15/06/2006 03:13
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Anonymous
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Anonymous
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Quote:
An ideal compromise would be the .64 housing 28rs with the same exhaust side as the 28r but i have a feelign that would be very pricey from TD if they made it up.
I've got this turbo! But it performance is almost identical to the GT28R so Nigel would be better off with an off the shelf 0.64 GT28RS.
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Re: Turbo choice
#132163
15/06/2006 14:32
15/06/2006 14:32
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Anonymous
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Anonymous
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Hi Nigel, good morning. A few more thoughts this morning... As you are possibly running in TOTB, the (0.86) would make possibly the faster drag strip turbo, it would be easy to keep the turbo on the boil, and you may find the torque curve slightly better 6000rpm+ which may net you a few tenths, only speculating mind you. The other issue is the clutch, the smaller versions will be harder on the clutch, and you may then have to consider a paddle to cope with the demands of the harder boost delivery. Joe
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Re: Turbo choice
#132165
17/06/2006 15:27
17/06/2006 15:27
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Anonymous
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Anonymous
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come on nigel... what did you get?
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Re: Turbo choice
#132166
17/06/2006 15:38
17/06/2006 15:38
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Joined: Dec 2005
Posts: 17,367
Staffordshire
Nigel
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I've accepted a bit more lag - will probably see 3,300 - 3,500 spoolup. It would almost certainly be higher than this on a more standard car, but the headwork, cams and straight induction should bring it back to more acceptable levels.
However, I now have a turbo capable of delivering 380+bhp, although I have a feeling that I won't get within 30bhp of this, due to other restricting factors, like clutch, injectors and rods (although I think I'll fit 16VT injectors for the Unichip remap)
Any guesses?
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Re: Turbo choice
#132167
17/06/2006 15:49
17/06/2006 15:49
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Anonymous
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Anonymous
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Re: Turbo choice
#132168
17/06/2006 16:21
17/06/2006 16:21
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Joined: Dec 2005
Posts: 554
Nottingham
Cyclone
Enjoying the ride
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Enjoying the ride
Joined: Dec 2005
Posts: 554
Nottingham
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Re: Turbo choice
#132170
17/06/2006 16:36
17/06/2006 16:36
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Joined: Dec 2005
Posts: 554
Nottingham
Cyclone
Enjoying the ride
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Enjoying the ride
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Posts: 554
Nottingham
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Lagtastic choice Nigel  , but with your additional mods you should compensate for that somewhat, should also give you more bhp potential and make the 1/4 mile times improve. Jules.
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Re: Turbo choice
#132171
17/06/2006 20:53
17/06/2006 20:53
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Anonymous
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Anonymous
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gt2871r Stichl has one of these fitted to his coop it has 396 hp @ 1.4 bar at redline  i think around 1.6 midrange  although he told me there is nothing before 4250 rpm even with the cams it will be slower spooling than a .86 rs around 5-600 rpm ,stichl runs a 2.75 turbo back exhaust though so if you go 3 inch you might gain 200
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Re: Turbo choice
#132172
17/06/2006 20:58
17/06/2006 20:58
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Anonymous
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Anonymous
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Jesus that is quite laggy!! I see base boost at just over 3000rpm hopefully more when i get the straight induction pipe someday but i have tyres and bits to sort before then!
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Re: Turbo choice
#132173
17/06/2006 21:46
17/06/2006 21:46
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Anonymous
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Anonymous
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Cool Nigel , I think you've suprised all of us here! , thought you were after as quick spool-up as possible Well, you should be able to push some numbers with this turbo, and on the strip will have you nicely into the 12's I would have thought, be interesting to see what you think it is like for track and road driving as its directly interchangable with the GT 28rs. Which GT2871R have you gone for? Joe
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Re: Turbo choice
#132174
17/06/2006 21:58
17/06/2006 21:58
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Anonymous
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Anonymous
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I would have gone for the RS .64 in all honesty for you nigel as i dont think they max out easily even with more mods unless u go for more cc's...
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Re: Turbo choice
#132175
17/06/2006 22:58
17/06/2006 22:58
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Joined: Dec 2005
Posts: 17,367
Staffordshire
Nigel
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Well, I spoke at length with Craig and Mano from Turbo Dynamics. I've been informed that the 2871 is no more laggy than the 28RS, and in some applications could spool even earlier (we discussed all my mods and the effects on spool-up)
I realised from the start that I was going to get some more lag than with my 28R. However, I've also been told that the 2871 will drive more nicely at more modest boost levels, with big power available from low(ish) boost.
I remember getting the 28R and finding that spool-up had moved from 2,500 to 3,000 and worrying that I wouldn't like it. Whilst I still occasionally get caught in the wrong gear, I've got very used to it. I imagine with the 2871, I'll just have to use one gear less when expecting to make a quick getaway.
When I sat down and thought about it hard, I realised that I wasn't necessarily looking for early spool-up - I was loking for nice off-boost characteristics for when I'm trundling in traffic at sub 3,000rpm. Keeping my existing turbo would have had no positive effect on this at all. All of my improvement in off-boost driving will come from the two main mods of the rebuild - headwork and cams. A Unichip remap (maybe with some 16VT injectors) should see a tweak in low-end tractability too.
However, I decided that the point where I enjoy the car the most is the massive surge of midrange to top end wallop. I love the way my car is still making more power when it reaches the redline. I love the way it howls after 4,000rpm. I love the way it continues to accelerate as hard after 100mph as it did under 100.
The GT2871R is just going to give me a load more of what I already liked, but from a 500 - 750rpm narrower band.
If only I could afford the forged rods, I'd be able to up the rev limiter with a custom G-Tec chip. However, I'm hoping that my standard rods will be good for 350+ bhp, which I'l be pretty happy with. At least I have the capacity to go for more bhp if I fancy risking it.
Can't wait now - decided that the full respray can wait until after TOTB - I need the car back ASAP to get some miles on it then take it for a remap.
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Re: Turbo choice
#132176
17/06/2006 23:18
17/06/2006 23:18
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Anonymous
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Anonymous
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Agreed offboost driving is a good bit of the experience of a coop, i noticed in teh last 2 days from gtec1 - gtec2 that off boost and sub 3k pickup is much better and smoother and even idle has improved as well for me Just have to find out what teh fuelling is like on higher boost as i still running medium boost of a maz spike of 1bar settling to about 0.8/0.9 when movign quick
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Re: Turbo choice
#132177
18/06/2006 00:20
18/06/2006 00:20
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Anonymous
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Anonymous
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Nigel, my cars in the middle of its remap, and at 345bhp at lunchtime today, a very hot day. I'm hoping for 350bhp come when she's finished , and that's with the smaller GT28rs. In all honesty with the GT2871r, I think you will find it easy to get 350bhp+ !! joe
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Re: Turbo choice
#132178
18/06/2006 05:10
18/06/2006 05:10
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Anonymous
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Anonymous
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I'm really not having a good time of it. Having got the actuator problem sorted, my 3071wg has decided to give up the ghost  Most likely reason is bearing failure (cause of which to be assertained) but the out come of which is a compressor wheel bashed to pieces thanks to touching the housing. Seems to also be a fair bit of play in the shaft. Anywayz will be going to TD for them to diagnose / fix / replace etc Not gonna moan much (yes I'm depressed, but hey I'm still here!), but the car was beginning to run very well. 1.1bar equated to 280bhp and each extra 0.1bar was worth aprox 20bhp on top I could see boost at very low revs, but only about 0.5bar up to 4000rpm where it would quickly increase to a bar by 5k and then go wild to the red line. Yes, that seems like a small HIGH POWER band, but if I increased the rev limit to aprox 8k, it would transform the car. The other interesting thing is, even though its low boost low down, the car is still producing the same power as my hybrid was at 1.3bar at the same revs.
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Re: Turbo choice
#132179
18/06/2006 05:34
18/06/2006 05:34
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Anonymous
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Anonymous
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Fergie, really sorry to hear the news  , very unusual to break a roller bearing turbo indeed, although I believe JohnS did the same to his. It will be interesting to hear what TD have to say. I found that increasing the boost beyond 1.4bar with the GT28rs (0.64), did not yield any appreciable benefits. How did you find controlling the boost at 5000rpm plus? as the 2871r and 3071r hit their 'sweet spot' and take off! Was the mapping going fine as well? joe
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Re: Turbo choice
#132180
18/06/2006 08:48
18/06/2006 08:48
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Anonymous
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Anonymous
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I have read that as well. Im sure i read something on one forum saying that the highest efficient level for the rs 64 was 1.5bar and as i dont intend to mod my car that heavily i will never push over 1.3bar ever, at the moment i tootle about on the lowest boost possible! I have heard of the odd GT turbo going due to oil starvation but it has to be pretty severe to cause it due to their design they can cope with it better than a journal bearing, although not advisable i did know at least 1 of the 2.4 guys blew a turbo up but i thought Mav had as well, maybe a different one. A coop that would rev to 8k would sound very sweet me thinks can the bottom end, even uprated take it though as i havent heard of it before in the coop world... Im hitting the same boost as fergie but about 1500rpm lower! :surprised: now that is scarey and shows what the internal mods alone are enabling you to do
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Re: Turbo choice
#132181
18/06/2006 14:09
18/06/2006 14:09
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Joined: Dec 2005
Posts: 286
Germany
Stichl
Making a profit
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Making a profit
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Posts: 286
Germany
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Hi,
I have a GT2871R (with big compressor wheel) and 0,86 turbine installed... below 4250rpm you won´t find "any utilizable power"...
I have done head work, too, plus a 3"- Pipe +2,75" exhaust + sport cat, short induction and so on...
I do not know the effects of a CB-cam.
But I think that you will gain a similar result to mine...
To get 396HP I had to adjust the boost to 1,7bar overboost and 1,6ar redline...
FOR SURE you will get better results with a GT28RS in lower revs...
May be the 0,64 housing would be a solution. But then you could get problems with the exhaust temps because of back pressure
Juergen
20VT coupegrale 4x4
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Re: Turbo choice
#132182
18/06/2006 19:04
18/06/2006 19:04
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Anonymous
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Anonymous
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The plot thickens Taking the turbo off, I've noticed a hairline crack just to the left of the collector. This may explain my lack of boost that I was blaming on a soft actuator Not sure how easy it will be to weld insitu and I'm not too sure about taking the manifold off when aircon is ontop of it!
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Re: Turbo choice
#132183
18/06/2006 19:08
18/06/2006 19:08
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Anonymous
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Anonymous
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Quote:
Hi,
I have a GT2871R (with big compressor wheel) and 0,86 turbine installed... below 4250rpm you won´t find "any utilizable power"...
I have done head work, too, plus a 3"- Pipe +2,75" exhaust + sport cat, short induction and so on...
I do not know the effects of a CB-cam.
Hmmm, I don't think anyone have noticed any benefit of spool-up with the cams?
joe
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Re: Turbo choice
#132184
18/06/2006 19:45
18/06/2006 19:45
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Anonymous
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Anonymous
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You really need to take it off to weld it up properly if its the standard unit im afraid Fergie, its possible to weld in situ but i bet it will be a bugger! and harder to clean the surfaces up as well.. plus while its off you can put welds in other places to help strengthen it as well i would imagine.
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Re: Turbo choice
#132188
18/06/2006 21:31
18/06/2006 21:31
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Anonymous
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Anonymous
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Owen only map them if they installed it IIRC...
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Re: Turbo choice
#132189
18/06/2006 22:46
18/06/2006 22:46
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Anonymous
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Anonymous
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Millway's RR is not capable of mapping cars over about 280 bhp and your torque will be a real problem for their rollers, also very poor cooling. Owen Devs will only do the ones they fitted as they haven't suppled the Unichip for several years now. Get a Motec there though So you are left with PTS, and we both enjoy their excellent customer service . You could try Engine Advantages, Witham, Essex, Roger is thinking about using them. I was warned off using the larger 16VT injectors (I have a set of 4) due to fuelling problems that can't be controlled by the Unichip (it's to crude) so I will be very interested to hear if you manage to use them and get a successful map.
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Re: Turbo choice
#132190
19/06/2006 00:22
19/06/2006 00:22
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Anonymous
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Anonymous
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H Andyi, I was also warned about mapping with 16vt injectors for the same reason. If you have a quiet word in Grahams ear, you should be able to reduce all of the fuelling maps by a set percentage , and then map with that. One of the biggest problems running big power and the Unichip is that you are beyond the capacity of the air/flow meter above 300bhp (you see the voltage max out), so the ECU has to rely on in built maps to 'guess' the fuellingand the more power you run, the more 'out' it will be. Paul at PTS is aware of all these probs, and did suggest creating a custom fuelling ECU for the 16vt injectors. joe
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Re: Turbo choice
#132191
19/06/2006 00:24
19/06/2006 00:24
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Anonymous
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Anonymous
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With the unichip could you not just use a better method to sense the airflow though as i know you can with teh motec and the likes but would think the UNICHIP should be able to make use of such a thing?
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Re: Turbo choice
#132192
19/06/2006 00:47
19/06/2006 00:47
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Anonymous
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Anonymous
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As far as I'm aware with the current unichip, the only real problem is above 5k where at that level the mapper has to 'guess' % of fuel to pull out.
We know the 16vt injectors are good for 400 - 420bhp so not too hard to control based on boost and the signal from the wideband during mapping.
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Re: Turbo choice
#132193
19/06/2006 00:48
19/06/2006 00:48
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Anonymous
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Anonymous
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Hello Juergen, I was referring to your car in my earlier post I’m glad you posted I think you’re the only person with a gt2871r fitted to a coop, could you please tell us at what rpm you hit 1 bar/14.7psi boost when in 3rd gear cheers dan.
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Re: Turbo choice
#132194
19/06/2006 00:56
19/06/2006 00:56
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Anonymous
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Anonymous
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Can they not get rid of this 'guestimation' by using a wideband lambda and seeing injector cycles and stuff? ie with the help of a wideband lambda and setup barnacle widgit?
Also do they not need to provide a little bit more on the 5th injector than the others as Iceberg has said itsn near enough always that one that goes due to underfuelling and he believes its due to the airflow and some other things into that cylinder...
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Re: Turbo choice
#132195
19/06/2006 01:22
19/06/2006 01:22
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Anonymous
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Anonymous
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Kingpleb, yep you can use a MAP sensor to get rid of the a/f meter issue, the new Unichip allows support for this, although I heard via Paul at PTS about a possible 'module' for the current Unichip.
Its easy to map, but in the absence of anything meaningful from the a/f meter then the ecu has to rely on throttle position, and charge temperature to guess load, the rising rate fuel regulator also allowing increased fuel pressure with increasing boost.
Other ways round the airflow meter issue is to fit a larger one of course, or house the current one, a tube within a tube of sorts so you can use its reduced air flow range to predict a wider range of air flow.
The MAP sensor is the ideal option though.
joe
ps I thought the 5th cylinder failing was due to having the shortest manifold branch?
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Re: Turbo choice
#132196
19/06/2006 01:26
19/06/2006 01:26
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Anonymous
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Anonymous
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Ahhh i wonder how much this module will cost for either version and then for the MAP and wiring. Im guessing you could salvage a MAP from antoher vehicle and nick the wiring loom from it as well but would mean the standard ecu wouldnt do much other than go off its maps for not getting any data from that then?
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Re: Turbo choice
#132197
19/06/2006 01:58
19/06/2006 01:58
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Anonymous
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Anonymous
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I have also bought a 2871rs 2 weeks ago, getting fitted next week...The engine internals are quite standard, and the turbo specialist suggested the 2871 is not more "laggier" than a 2860rs, and then you can always get more power from it if you want...So this became my choice, and cant wait to see what results i get next week after install/mapping
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Re: Turbo choice
#132198
19/06/2006 02:01
19/06/2006 02:01
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Anonymous
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Anonymous
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Dunno really, just going off what iceberg said to me. if anything it would help having the branch shorter i would think as getting the gas to the turbo still hot as poss and out as quick as poss...
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Re: Turbo choice
#132199
19/06/2006 02:15
19/06/2006 02:15
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Anonymous
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Anonymous
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This is a fantastic thread, the old forum had such 'nuggets', but this year there's been a dearth of such things,.. the tuning thread being filled up with dump valves and the like. Its great seeing the variety of ways towards coupe tuning, and the 2871r and 3071r are fascinating , all credit to Nigel, Fergie, Stichl et al for doing this ,...... when I got my novitec chip 4 yrs ago, noone in the UK had fiitted one!! yes, can't wait to see what power and powerband these cars produce, and how to overcome the various obstacles they produce. regards joe Kingpleb, I wonder why the 5th injector would be weakest ?...
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Re: Turbo choice
#132200
19/06/2006 02:18
19/06/2006 02:18
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Anonymous
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Anonymous
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i too enjoy seeing this within the coop fold It shows how much we commit to finding the best for our cars and tuner shoudl take note of it, we are no average scooby/evo owner just after a quick bolt on. we look at what else needs bolting on to compliment that bolt on
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Re: Turbo choice
#132201
19/06/2006 03:13
19/06/2006 03:13
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Joined: Dec 2005
Posts: 17,367
Staffordshire
Nigel
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OP
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Posts: 17,367
Staffordshire
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You know that feeling when you commit to spending a truckload of money on the Coupe? I've had all weekend to contemplate my actions, and here's my conclusions. Stichl - I reckon your car is not getting the best out of the GT2871R at the lower end (although there's clearly no doubting your top end performance - I'd be staggered if I got anywhere near your 397bhp). 4,250rpm spoolup is very late, and goes against what I've read from many other applications on other cars. Yogisdk - we'll have to keep in touch and compare notes - I can't wait to see what your car gives after mapping. I've read MANY threads about GT2871 spoolup on many different car forums, and I'm clinging to the fairly common belief that on a car with a decent VE (ie 90%+), I'll get spoolup at the same or earlier than I would with a GT28RS. My estimation is that with the cams and headwork and straight induction, I'll have a significantly better off-boost drive anyway, so even if I've got a 500rpm later spoolup, it would pi$$ me off too much. Perhaps I'm just trying to kid myself that I'm not just about to turn my previously tractable Coop into a lag-monster. Only time will tell, but I'm sufficiently confident with my decision that I WON'T be nagging Turbo Dynamics on Monday morning with a load of "have I done the right thing" questions. The only two issues I have now are 1) I've read that the 2871 doesn't come with a wastegate actuator - certainly they didn't ask me what pressure I wanted it set at (going for 0.8 - 0.9 bar) - so I guess I WILL be calling them after all 2) If everything comes together, there's a slim chance I might be pushing over 350bhp, in which case, my choice of clutch will be suspect (GTA / Walkers combo) - however, I absolutely MUST have a clutch I can live with for everyday commuting and rush-hour stop / start traffic. I remember Joe's trials and tribulations with his paddle clutch, and I'm NOT going down the same route. It's like being 8 years old on Christmas Eve - I can't wait
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Re: Turbo choice
#132202
19/06/2006 03:26
19/06/2006 03:26
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Anonymous
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Anonymous
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I would have gone with ATP for the turbo as god knows how much TD want for it although it does mean it should arrive at your house ready to be bolted straight on. I hope im wrong with the lag issue but i suspect even with your mods your spool up will be higher up the rev range than even what mine is at the minute with the standard induction route.... As logn as you make good use of the rev limiter in TOTB and such like i cant see the spoolup affecting you much The clutch should still last i reckno as logn as its not daily your dumping the clutch for launchs or suchlike i dont think you could go any higher up anyway unless you found a good clutch from a diesel engined car to take the abuse as its more the torque i think that kills them off and the new VNT diesels can cope well with high amounts I bet by lunchtime TD will have had a good long chat to you to assure you that your credit card can be relieved of said money and it will all be fine PS Im a sceptic and i have far too many irish attributes in me that people confuse with scottish ones. Must be why i got LPG anyways
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Re: Turbo choice
#132203
19/06/2006 03:31
19/06/2006 03:31
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Anonymous
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Anonymous
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Hey Nigel Sorry to ask but what is VE?? I was (am) also worrried about the lag issue, but talked to the main turbo people here and all went to say the 2871 is not going to be laggier than the 2860 in the coupe...I guess we will see, i guess all comes also down to how much boost you want from it, but i believe 4250 rpm before boost sounds doubtful ( i hope so!!) I guess the actuator you can set it up yourself, i dont know what boost it comes from factory but i know there is one in mine, as i have it right here in front of me in its nice Garrett box
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Re: Turbo choice
#132204
19/06/2006 03:37
19/06/2006 03:37
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Anonymous
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Anonymous
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What is ur FULL BOOST rpm kingpleb?
Ross
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Re: Turbo choice
#132205
19/06/2006 03:51
19/06/2006 03:51
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Anonymous
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Anonymous
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how do u mean fullboost? i run about 1bar peak at the minute and i think that is just over 3000rpm at the mo. id need to check on my way home though as i need to swap tyres over now the weather has closed in as slicks and rain dont do well
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Re: Turbo choice
#132207
19/06/2006 04:14
19/06/2006 04:14
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Anonymous
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Anonymous
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Quote:
how do u mean fullboost? i run about 1bar peak at the minute and i think that is just over 3000rpm at the mo. id need to check on my way home though as i need to swap tyres over now the weather has closed in as slicks and rain dont do well
Oh right. I have the gt28r, and it was kicking it at 2700rpm with 1.3 bar. After i get my car back with headwork and boost controller i'll be hoping for earlier!!!
Ross
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Re: Turbo choice
#132208
19/06/2006 04:37
19/06/2006 04:37
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Joined: Dec 2005
Posts: 994
Drakelow
Jamiepm
Club member 1989
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Club member 1989
Enjoying the ride
Joined: Dec 2005
Posts: 994
Drakelow
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Nigel, A couple of points to consider which people may not agree with. Firstly on my car the headwork I've found makes a small improvement to spool up but really shows its stuff at higher revs, so I'm not sure you'll see that much difference.Secondly the 2871r will be laggy compared to the 0.64 RS, I'd say it would probably be laggier than the 0.86 RS and for the benefit of a headline figure I think would give you a better utilisation of available power.I also know of guys that have fitted this to 4 cylinder applications and all of them commented that below 4k it is flat as fart. If you want a drag strip monster then I'd guess you've gone down the right route but for a daily driver I reckon you'll be disappointed. So to summarise, cams won't really affect spool up as VE is relative to revs/volume of air, headwork in general gives most benefit at higher rpms and the straight inlet will have a positive effect but overall . Without dragging up forum history, can peeps remember the debates over the 28RS with the 0.86 housing?? most 'experts' suggested it would be to laggy for real world use and yet more and more people are fitting them and without doubt this side of 4k the 2871R would be down on power compared to a 0.86 RS Jamie
She's alive!
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Re: Turbo choice
#132209
19/06/2006 05:35
19/06/2006 05:35
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Anonymous
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Anonymous
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I'm not the most technical when it comes to turbos, but other point to bear in mind is the cars gearing. My rev limit is 7200 and if I change from 1st to 2nd any earlier than that, I fall out my efficiency window. Not good when your drag racing
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Re: Turbo choice
#132210
19/06/2006 05:47
19/06/2006 05:47
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Anonymous
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Anonymous
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Hi Nigel,
Is it the 48 compressor trim, 0.64 a/r turbine housing version of the GT2871R?
The 71 turbos have the same tubine options as the 60's but bigger compressor wheels, so the 71 will spool up slower than the equivilent 60, but support higher flow rates.
Has anyone looked at fitting one of the GT2860R's for the R34 GT-R or R34 GT-RN1?
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Re: Turbo choice
#132211
19/06/2006 05:52
19/06/2006 05:52
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Anonymous
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Anonymous
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Fergie you're right, I'd guess you need at least a 3000rpm power band.
All you have to do is either calculate it with the gear ratios, or more simply, rev the car in
1st,2nd, 3rd etc to redline then change up and see what t
e revs are, then that is where you still want to be in the power band.
joe
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Re: Turbo choice
#132212
19/06/2006 06:13
19/06/2006 06:13
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Anonymous
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Anonymous
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I keep wondering, why would it be so laggy as people claim, when it has the same turbine size as a 2860rs, but a biger compressor housing? I am therefore thinking it will spool as fast as a 2860rs, while being able to blow more air...
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Re: Turbo choice
#132213
19/06/2006 06:51
19/06/2006 06:51
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Anonymous
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Anonymous
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Ok hear are the figures. at 2.5k i see 0.5bar, at 3.2 i see just over 1bar and then quick shoot back down to 0.9/0.8 its hard to tell when your travelling that fast... This is all done in 5th gear as well. One scarey thing i found out on the private bit of road i often use. i can hold 140leptons without any boost now thats scarey and thats with no known headwork, no cams, no induction mod... The longer i own this car the longer i fear for my licence i can say if thats what i can get on a small private strip and hold for a mile or so without worry on an autobahn these things must fly quickly with these kinda mods! Im guessing the CD of the car helps as well I still think you would be better off with the .64 housing RS Nigel as you dont need massive power for everyday use and fot TOTB you can work on traction more and other things too, ie track tyres and stuff
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Re: Turbo choice
#132214
19/06/2006 08:32
19/06/2006 08:32
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Anonymous
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Anonymous
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See that you have .64 housing right?
How is your spool up without the induction mod will??
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Re: Turbo choice
#132215
19/06/2006 13:05
19/06/2006 13:05
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Joined: Dec 2005
Posts: 286
Germany
Stichl
Making a profit
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Making a profit
Joined: Dec 2005
Posts: 286
Germany
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Hmmm... I don't think that I did anything wrong to get this big lag... I think it is the turbo itself. Remember - The compressor wheel is the same like in the GT30-units. Therefore it is clear for me that you will gain a lot of lag with a GT2871R... Before I had installed a GT28R-unit with the same setup (one exception: the exhaust + pipe was a restrictive one - means the assumptions even were worse...). Nevertheless I got almost no lag - even a better respone than the original T28 unit... I did a run on rolling roads... here is the result (sorry for cutting off the peak power - the setting of the plotter was wrong when doing the run. We did not suspect such a peak power)... http://service.gmx.net/mc/5DV0MNAfl65qfCRGEJTIa6Bd9QYNMDpress:"multimediacenter starten", then you can see the "late response"... The engine has original internals - means original rods (lightened + shot peening) + original pistons. Next month I will have the possibility to gauge the length of the rods - then I will see, if the ~500NM will have damaged / compressed the rods (have been installed then for about 10000km). Juergen
20VT coupegrale 4x4
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Re: Turbo choice
#132216
19/06/2006 17:47
19/06/2006 17:47
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Anonymous
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Anonymous
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Oh god is so much power/boost really possible on standard internals? :O I thought 350 was tops
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Re: Turbo choice
#132217
19/06/2006 17:53
19/06/2006 17:53
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Joined: Dec 2005
Posts: 17,367
Staffordshire
Nigel
OP
Forum veteran
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OP
Forum veteran
Joined: Dec 2005
Posts: 17,367
Staffordshire
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I've spoken with Craig again at TD - he feels that Stichl has probably bought an off-the-shelf GT2871R with a 0.86 AR turbine housing - hence the lag.
Here's the exact spec of my turbo:
0.64AR turbine housing
76 trim turbine wheel (same as GT28RS)
48trim compressor wheel , with 49.19mm inducer and 71mm exducer, in a 60AR housing
1 bar actuator
Basically, the GT28RS turbine side, in 0.64 AR form is known to be good for the Coupe, and as long as the engine can flow the exhaust gasses, is plenty enough to drive a bigger compressor.
The 71mm compressor side of the 2871 will simply flow more air, without costing lag fom the turbine side.
I'm not 100% sure I understand all the above, but Craig is certain that I'll have no more lag than a 0.64 GT28RS, but will have better power than a 0.86 GT28RS
Best of both worlds?
Lets see......
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Re: Turbo choice
#132218
19/06/2006 18:10
19/06/2006 18:10
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Anonymous
Unregistered
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Anonymous
Unregistered
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Hi nelson, ive put what i get for spool up in the post just before yours. The only induction mod i have is a cone filter. not a straight induction pipe or anything yet
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Re: Turbo choice
#132219
19/06/2006 18:15
19/06/2006 18:15
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Anonymous
Unregistered
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Anonymous
Unregistered
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I have bought the one with 0.86 turbine also, and as i can see this is the same specs as the 2860rs 0.64 turbine specs: 53.8mm and 76 trim, so i dont get the extra lag issue? Anyways its still rated as 0.86 in the 2871rs, so i guess the housing must be different in some way...i guess i just bought myself into a laggy situation  Well, lets see
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Re: Turbo choice
#132220
19/06/2006 19:09
19/06/2006 19:09
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Anonymous
Unregistered
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Anonymous
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Nigel, I can't wait to see the results , sounds interesting bbecause I too have seen websites saying the 2871R being no more laggy than the 28rs, but then also others and acutal installs that have shown this. Our cars will be very similarly modified, except I don't have the gas lowed head or the forged pistons ,but she ran 363 bhp and 323lb/ft this morning. What should put your mind at rest that this was at 30degC, and the clutch is holding well, so for sure the GTA /Walkers combo can handle 320 lb/ft and 360bhp+ , although I know when its cold ,she becomes even faster and on very cold days sub 5degC the clutch can slip, g*d knows what the torque must be like then I think with a more progressive turbo, it will be less strain on the clutch anyway Joe
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Re: Turbo choice
#132221
19/06/2006 19:14
19/06/2006 19:14
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Anonymous
Unregistered
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Anonymous
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Hey Doc
Nice results!! Are you then running on standard internals other than the C&B cams, all other standard?
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Re: Turbo choice
#132222
19/06/2006 19:20
19/06/2006 19:20
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Anonymous
Unregistered
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Anonymous
Unregistered
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Stichl just watched your video and rolling road results, thats an amazing curve, incredible power band between 4250 and 5250!!
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Re: Turbo choice
#132223
19/06/2006 19:32
19/06/2006 19:32
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Anonymous
Unregistered
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Anonymous
Unregistered
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Hi yogisdk yep, standard pistons rods and standard head. Joe its right at the limit of this turbo though, anymore boost and then I will start to get predetonation. I think more torque and maybe a little bit more power would be available on a cold day.
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Re: Turbo choice
#132224
19/06/2006 19:34
19/06/2006 19:34
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Joined: Dec 2005
Posts: 17,367
Staffordshire
Nigel
OP
Forum veteran
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OP
Forum veteran
Joined: Dec 2005
Posts: 17,367
Staffordshire
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I've just spent a while trying to learn how to read compressor maps and how it will apply to my car. Basically, I THINK I should be able to get over 1 bar by 3,000rpm and still be close to the turbo's efficiency island (would be about 71% efficiency) take a look here http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT28/GT2871R_743347_1.htmUsing a VE of 95% (which according to Begbie would be about right for a car with a flowed head), I've calculated that (everything else being optimum) it should deliver the following: 1 bar at 3,000 rpm @ 72% efficiency 1 bar at 4,000rpm at 75% (max) efficiency 1.5 bar at 5,000rpm at 75% (max) efficiency 1.5 bar at 6,00 rpm towards the edge of the efficiency island (about 70%) 1.2 bar at the redline at 70% efficient I also reckon it should give about 300bhp @ 1 - 1.1 bar All of this is using intake temps in the region of 25 - 30 degrees - any cooler and I can expect a bit more.
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Re: Turbo choice
#132225
19/06/2006 19:36
19/06/2006 19:36
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Anonymous
Unregistered
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Anonymous
Unregistered
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Didn't noticed That's a very very good spool up for a RS unit If you have spoll up just after 2.5k you didn't noticed more lag than the original unit for sure So how many mates are saying that their units only start to spool at around 3.2 or above 
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Re: Turbo choice
#132226
19/06/2006 19:48
19/06/2006 19:48
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Anonymous
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Anonymous
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Nigel, can you explain a bit more how to calculate these values, also if i am using the .86 housing? I would really like to know how much power I can expect with 1.3 bar or so, and when will this come (on std engine internals)...
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Re: Turbo choice
#132227
19/06/2006 19:57
19/06/2006 19:57
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Anonymous
Unregistered
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Anonymous
Unregistered
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I dont know who else is running the same unit at the minute and has got it laggier. i think my 3" downpipe and decat system helps a lot though
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Re: Turbo choice
#132228
19/06/2006 19:59
19/06/2006 19:59
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Anonymous
Unregistered
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Anonymous
Unregistered
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Good results there Doc need to go down in january to the rollers and do a power run me thinks as i bet the fuelling will need to be setup again for the amount of air you could flow on a cold day with a good FMIC it should be covered in ice at speed, i know the oil cooler sometimes gets it as ive seen it on my own coop but that was about 80-90leptons average when it was about 2deg 'c outside. this winter i think i may put a bit of card in front of half the oil cooler to help keep the oil a bit warmer on a run
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Re: Turbo choice
#132229
19/06/2006 20:13
19/06/2006 20:13
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Anonymous
Unregistered
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Anonymous
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LOl, Nigel, yours will be one of the most talked about coupes over the next month!!,.. even on my summer hols, I am sure and be sad and log in from time to time to see how the monster is shaping up ! Kingpleb joe
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Re: Turbo choice
#132231
19/06/2006 20:28
19/06/2006 20:28
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Joined: Dec 2005
Posts: 12,295
Sandhurst
Begbie
Ex El Presidente
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Ex El Presidente
I AM a Coop
Joined: Dec 2005
Posts: 12,295
Sandhurst
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Quote:
Nigel, can you explain a bit more how to calculate these values, also if i am using the .86 housing? I would really like to know how much power I can expect with 1.3 bar or so, and when will this come (on std engine internals)...
Understanding compressor maps
Refer to my post at the top of the page, simple calculation to get a understanding of airflow / efficiency, or for anyone who doesn't want to read it, i will paste it here
Quote:
Simple way:
the pressure ratio you have to always add 1bar on, this is for atmospheric pressure, so if you want to run 1.5bar of boost, you need to look at 2.5bar on the compressor map.
The lbs/min is your airflow. From various scouring of the t'internet it seems 1lb/min = 10bhp, so if you know what your BHP aim is, you know can work out your airflow.
So in whittlers case he is doing 320bhp/10=32lbs/min
There is a more complicated way of working your airflow out which is...
(L x rpm x VE x Pr)/5660
L = Litres
rpm = Max rpm you want to run
VE = Volumetric efficency (90% for std engine, 95% for headwork and 100 or 105% for race engine)
Pr = Pressure (boost)
So for my engine it would be something like this
(2 x 8000 x 95 x 2.2) / 5660 = 590.81CFM
to convert this into lbs/min multiply it by 0.7
590.81 x 0.7 = 413 (add a decimal place in)
so my airflow @ 8000rpm with 1.2bar boost is 41.3lbs/min, so you go and look at the compressor map and plot the boost against the airflow, then you know whow efficent it is at max rpm
Your car is Usain Bolt with wellies
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Re: Turbo choice
#132232
19/06/2006 20:32
19/06/2006 20:32
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Anonymous
Unregistered
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Anonymous
Unregistered
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really great thread (nigel,doc,fergie,will)
oh , and you too Stichl , phenomenal power !!
cheers.
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Re: Turbo choice
#132233
19/06/2006 20:38
19/06/2006 20:38
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Anonymous
Unregistered
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Anonymous
Unregistered
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Looks good and maybe try and get a pic of it this winter should i get it again but i hope to avoid it as it cant be good for the oil. Noticed this in the xantia as well coming back from stranrear down the A74 and M6 at the top that the engine temp would never go above 60 either Anyway back on topic i cant wait to see what this gives you Nigel, hopefully it wont be too laggy if at all and maybe be another route for others to follow. How much is this costing you from turbo dynamics if i may ask as im guessing about £1200+?
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Re: Turbo choice
#132234
19/06/2006 22:37
19/06/2006 22:37
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Joined: Dec 2005
Posts: 17,367
Staffordshire
Nigel
OP
Forum veteran
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OP
Forum veteran
Joined: Dec 2005
Posts: 17,367
Staffordshire
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Quote:
How much is this costing you from turbo dynamics if i may ask as im guessing about £1200+?
No, you can't ask - my wife occasionally looks over my shoulder when I'm browsing the forum
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Re: Turbo choice
#132236
19/06/2006 23:20
19/06/2006 23:20
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Anonymous
Unregistered
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Anonymous
Unregistered
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Gulp thats not going to be cheap then!!! lol
I bet she wishs she had let you buy the massa when she sees all the bits come for it!!!
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Re: Turbo choice
#132237
20/06/2006 02:53
20/06/2006 02:53
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Joined: Dec 2005
Posts: 286
Germany
Stichl
Making a profit
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Making a profit
Joined: Dec 2005
Posts: 286
Germany
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Quote:
I've spoken with Craig again at TD - he feels that Stichl has probably bought an off-the-shelf GT2871R with a 0.86 AR turbine housing - hence the lag.
Here's the exact spec of my turbo:
0.64AR turbine housing
76 trim turbine wheel (same as GT28RS)
48trim compressor wheel , with 49.19mm inducer and 71mm exducer, in a 60AR housing
1 bar actuator
Basically, the GT28RS turbine side, in 0.64 AR form is known to be good for the Coupe, and as long as the engine can flow the exhaust gasses, is plenty enough to drive a bigger compressor.
The 71mm compressor side of the 2871 will simply flow more air, without costing lag fom the turbine side.
I'm not 100% sure I understand all the above, but Craig is certain that I'll have no more lag than a 0.64 GT28RS, but will have better power than a 0.86 GT28RS
Best of both worlds?
Lets see......
Meanwhile there are are three different types of gt2871r.
You will install the smaller version - http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT28/GT2871R_743347_1.htm capable to support 385HP
I have the version with bigger compressor wheel capable of doing 475HP
http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT28/GT2871R_743347_2.htm
Interesting would be the very new version 15 - have a look at this: http://www.turbobygarrett.com/turbobygarrett/catelog/Turbochargers/GT28/GT2871R_472560_15.htm
This turbo is capable of doing 460HP and should be the best GT2871R regarding response!
All these turbos are off-the-shelf.
Juergen
Last edited by Stichl; 20/06/2006 03:02.
20VT coupegrale 4x4
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Re: Turbo choice
#132241
07/07/2006 15:30
07/07/2006 15:30
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Joined: Dec 2005
Posts: 3,158
Near Reading
JohnS
I need some sleep
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I need some sleep
Joined: Dec 2005
Posts: 3,158
Near Reading
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What if I were to say that for the money you would get more benefit by fitting an external wastegate and screamer pipe? I have never used an intermediate adapter - I have always had a full GT25 flanged 3"+ downpipe. There are people on here who have made that transition and so are far more qualified to say the exact difference. What I would say is that there is just as much restriction on the other side of the turbine housing - not just the cr*ppy manifold but the internal wastegate too which creates a lot of turbulence and back pressure. Thus my first statement
Former low boost hero - 616BHP@1.5 bar. 2.4 20VT RIP
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Re: Turbo choice
#132242
07/07/2006 17:52
07/07/2006 17:52
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Anonymous
Unregistered
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Anonymous
Unregistered
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Jamie tried to fit a Nissan twin pipe exit off the turbo, but apparently it was very very difficult to fit due to extreme space considerations, although if you were very inventive with the routing it might just be possible?, certainly anyone who's taken off a 3"downpipe knows how little room there is.
I did notice a difference when I changed from the v-band to the full 5-stud setup, but also ported the manifold at the same time,.. not a huge difference mind you, but say 100-150 rpm spool-up and extra 'urgency' throughout the rev range.
joe
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Re: Turbo choice
#132244
07/07/2006 20:00
07/07/2006 20:00
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Joined: Dec 2005
Posts: 3,158
Near Reading
JohnS
I need some sleep
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I need some sleep
Joined: Dec 2005
Posts: 3,158
Near Reading
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I will probably fit an external wastegate at some point. The reason I haven't to date is that once my 2.4 was done I used the same dual ballbearing CHRA and compressor housing as my old turbo (from my 2.0 days) for my new turbo so that my turbo upgrade was pretty cheap plus I already had a proper 3"+ GT25 flanged downpipe. Now if I had a 2.5"-3" Vband downpipe the move to an external wastegate would be really easy and relatively cheap for me like it is for you. The step to a GT25 exhaust flange to my mind will make it harder for you to go for an external wastegate in the future. Maybe we should swap downpipes
Former low boost hero - 616BHP@1.5 bar. 2.4 20VT RIP
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Re: Turbo choice
#132245
08/07/2006 01:13
08/07/2006 01:13
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Anonymous
Unregistered
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Anonymous
Unregistered
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hehee, its hard to compare but going from a 3" downpipe then 2.25" decat to the full 5-stud to 3" decat saw 335bhp go to 362bhp, 300 lb/ft to 323 lb/ft although more boost 1.5/1.4 bar,... my unichip map was only altered slightly, reducing advance if anything. I had a boost leak with the first run, but it does at least give you some idea. In reference to my old post, I later found that I had a leak in the actuator pipe, hence the reason for the rising boost levels !;) I'd just say the car feels more aggressive to drive, more torque but how much I don't know. joe
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