Rolling road section

Hi, just a link that I thought ought to receive some more attention 413bhp!!!

Joe

Joe - I've been watching this for a while. I know you've pushed your car regularly on high boost and despite your best efforts you have yet to nuke the standard internals. Are they going to go progressively, or just go pop if they are out of tolerance?

of the high powered cars we know that had piston failiures do we know how many of them were mapped, and if they were mapped, then how aggressively? Is the issue the boost pressure if the car is mapped a good few degrees off det?

I think that Nyssa7 could give some valuable input to this, but have not seen him post recently?

I'll bet most of the piston failiures is due to weak mixture.. ie monkey business done somewhere along the line.

Now that we have good discussion on going , one question of EGT values.
In my case I can feel the car runnning much stronger, when I have EGT above 900 degC. Under it, I can clearly feel that something is braking my driving.
Joe or anyone elese with EGT, can you feel anything like that and what is normally your EGT values when pushing hard?
I have warning light in 960 degC and once or awhile it goes near 1000 degC, especially near and above 7000 rpm with 4th or higher gear.

- Jari -

EGT = Exhaust Gas Temperature?

Can i ask the usefulness of this? Another toy wouldnt go a miss!!

Ross

@ jari

impressive results.....:-)

you are running standard injectors ?
how is your afr especially in higher revs and gears ?

how is spoolup / full boost with your 3071 ? i think you are running 0.86 t25 turbine housing, right ?


macki

I would feel pretty confident in saying it is fueling and detonation that cause the engine to let go more than outright boost.

EGTs give you an idea of combustion temps. Too high and you are likely running too lean (or too much boost/backpressure) which means more chance of detonation and melting a piston.

Hi Jari, despite my best efforts, I have not managed to get the EGT's to go above 900degC , only once! , I have heard that pistons start to melt above 950degC, so I have always considered 900degC as an upper maximum, although some highly tuned turbo cars do treat 1000degC as the limit.

When 'racing' an EVO FQ400 at Cadwell, I saw just over 900degC after a couple of laps of enthusiastic driving at 1.4 bar boost, more boost would have seen higher temperatures. I suspect, you are getting a little bit of detonation there pulling back the ignition timing, the Coupes det sensors are very sensitive!, I've seen them pull back timing, even when the driver wasnt aware.




I think both can happen, I've seen Geoffs Coupes pistons, a car running 1.4 bar regularly with a standard inter cooler, they didn't go bang, but the car got more and more smoky, and when the pistons came out the pistons had not melted, but the rings were all cracked and damaged and numerous micro fracture were seen between the crown and the first ring, the rings were so damaged and gummed up, they would not be sealing well atall!

Joe

Don't think my nfirst engine was mapped that aggressively, but equally don't suppose the 1.6 bar was doing the rods any favours! Also highly possible a missed gearchange contributed - we'll never really know

At the end of the day, if people want to build 400+bhp engines with stock internals, then fine. At least when they do let go, they can just plug another one in

Trevor - If I remember right you managed to put a rod through the block? What Bhp / torque were you running, also what rev limit / boost at the redline? I'm not disputing that if you go for big power on the standard internals then you have to be prepared for something to let go - but I am interested in what the reasonable safety margin is before this point, if we really dont know then so be it, but there's no harm in trying to find out.

This post is interesting to me as I have forged pistons but not rods. My car is 'running in' at the moment and I will be booking in for its final map with PT very soon. It has the potential to run very high figures however does anyone suggest a limit in BHP and FT-lb and Boost that I should run? Does PT monitor EGT when they map?

Ask rob at PT about the EGT monitoring. I believe the weak point on your car would be the rod bolts (thanks JohnS and others). The general consensus would be not more than 330 lbs / ft to be on the safe side, and not higher than 7,300 rpm as long as you have a balanced engine (gained from talking to as many people as I can – both on here and elsewhere, not through personal experience). Boost at the redline around 1.2 / 1.3 bar IMO (GT28R will probably hold about 1.2 or slightly less). You can ask rob to map the car to take into account the cap on the torque.

Thanks for the useful info. I am looking for a fast spool up and quick acceleration from stop right through midrange. I'm NOT interested in top speed or raising the rev limit even thought the engine is fully balanced.
I agree with you I feel that my only weak point is the Rods and rod bolts.
Turbo is the GT RSR.
My clicky below shows all the work done.
Barbz said that Nigel ran about 380lbs but told PT to back it down to about 340lbs as his turbo could easily hold it to redline. I feel I’m in the same boat as Nigel but with a smaller turbo. I just want the opinion of the forum before going to PT as I don’t want rob to push it too far.

Is the figures you guys qoute at the wheel?

It will be flywheel figures being quoted.

If you have the RSR, it will be around 320/330lb/ft that you'll be producing anyways, so i dont think that will cause a problem, according to suba and others.

Ross

I think someone got 340 lb-ft with the RSR, but that was at 1.7bar! You should be expecting 300 lb-ft with a more conservative 1.4bar edit: maybe a bit more if you have headwork.

I think that was Marcus - forged engine with nos thrown in for good measure.

Ok last point as I don't wanna highjack this thread too much
The RSR together with the headwork/Cams/Higher CR/H&S downpipe etc the power should be higher. I was thinking of setting the bar at 350lb and dropping the boost towards redline. Is that pushing too far?

1.7 + RSR = marcus.

This is giving me food for thought about stnd internals, but IF myself or Suba do decide to push the limits of stnd internals in this country, presumably a EGT is a worthwhile mod to try and install some safety into the system so we dont fry the pistons?

Ross

Isnt it a lower compression ratio you would be looking for? Also 350lb/ft is gonna bend the rods according to the experts. With headwork and cams etc there is the high possiblity that you will get near that figure but whether or not its safe to do so... although stnd internals in finland holding 347lb/ft...

When mapping yes - but tba I never really look at gauges when I push the car, always try to, but forget somehow. If it had an audible warning set up then it could be useful...

As most now know, i have my "worry gauge" and it keeps me occupied a lot of the time. Im running around 1.45 bar midrange, and my fuelling has re-adjusted itself to running high tens again (10.7/10/8) whereas at redline is running 11.9/12.0. Now i know i have the extra fuelling available because i can turn the boost up at redline and it will actually run richer (11.6) but can i up the midrange to see if its going to lean it out slightly more? 1.5 bar? I know Dr Frag runs that kinda power, but its always been labelled as bad bad bad. Would an EGT gauge show me whether or not im able to run this or not?

Ross

No, The compression now is 8.8:1



Actually he’s claiming 361lb/ft with the T04

Ok I’m going to set my limit at 340lb/ft with my fingers crossed

TurboJ, it will be very interesting to see how you get on with the RSR turbo.

Both myself and Flea got 330 lb/ft with the larger Gt28rs at 1.5 bar at the height of summer., mine was at the end of mapping at 38degC!, with a slipping clutch, the Coupe now feels a lot quicker , very noticeably so, but how much extra I don't know , but I suspect 330-340 lb/ft.

There's no point in going for huge torque/power figures on the rollers at high boost levels if you're never going to run them on the road,..... the RSR, should have a compressor efficiency between the R and the RS, so although a one off blat at 1.5 bar+ would be fine (as the intercooler heat sink will soak up most of the extra heat), it would soon overwhelm it and start to become too risky for the engine.

I would consider setting your boost level for your mapping at what you intend to run and according to the compressor map, so 1.4-1.5 bar would be a good maximum ,as its considered best not to go below 70% efficiency on the turbo, although many do push their smaller turbos way too hard ( I have been one of the most guilty of this! ).

Joe

Thanks Joe, I have had the same discussion with Barbz and he is not sure as to what my figures might actually be. He was really impressed with the level of headwork and inlet porting and he thinks I will produce a lot of power. All my parts came from TI except the machining work and actual engine building.

My intake charges should be low as my intercooler is a custom tube & fin design with a good surface area exposed as well as a water injection system.

1.4-1.5 sounds good for peak but I would drop it off nearer redline.

what kind of clutch will you be running j? are you going for a paddle item?

Barbz reckoned when i was speaking to him to run around 1.5bar 3k-5.5k revs and then drop it off to around 1.25bar above this..but its all to do with how much my std injectors will fuel for i suppose, and how much torque my clutch with hold midrange

Iain

I'll be using the 16VT injectors @ 3Bar.

Clutch is another thing. I've got the uprated walkers/GTA combo but I’m 95% sure it's gonna slip. If it does then gonna have to save my pocket money for the twin plate jobbie.

1.5Bar from 3K-5.5K is perfect then drop off the boost. It’s just how much torque will I be chucking out at 1.5 that worries me??? Guess only time will tell.

i will be using std. ones at 3.8Bar..

My clutch is also Walkers/GTA combo.. i took out my walkers paddle because it was horrible to drive, so i will get the torque dropped to stop slip hopefully..

Torque man i havent got a clue, i havent driven the car over 0.9bar yet until i know its safe

That clutch is rated to 300 lbs / ft only - Joe used to run is and had slip over 320 lbs / ft. I dont think it'll do the job.

wont the 16vt injectors create idle difficulties? Why not go for 20vt injectors with 3.8 bar fuel pressure?

yeah i know.. but i suppose all these rating depend on your driving style etc. so i will have to get PT to detune the torque to allow me to run this on my car, but as for Turbo J im not sure it will do his job

I'm in the same position - but there's no way I'm having the car mapped and telling them to stay below 300 lbs /ft or going to waste a days mapping time and money with a clutch that's not up to the job only to have to replace it and then come back and do it all over again.

Guys remember the Helix group buy Paddle or Organic.

Ross

yeah well imagine wasting another £500 getting there and back too lol

you are beginning to make me think im mad.. ive always been worried about making the trip and something letting me down

Rob and Barbz suggested I ran the 16VT @ 3Bar instead of the 20VT @ 3.8Bar

Ok so now I need to forget about the rods as my bigger problem is now the clutch

So gotta keep my torque at 300lbs

Are you running a walboro fuel pump TurboJ as Im going down the 16vt injector route aswell

I really recommend the paddle clutch. It is the only option if you want to go for big power and torque. Yes, it is different, and can be a little harsh, but I suggest you go for a drive in a car with one fitted and see what you think.

It will grips like hell, so you will never loose any of those valuable horses you are going for. I think you will be wasting your time and money to get Perfect Touch to map the car without a 100% perfect clutch. That is why I waited so long to have my car mapped.

As for the limits of the standard internals, I'm happy to sit back and see just how far the limit can be pushed. However, I think that much more power will meerly expose the limits of the grip / traction.

TurboJ, though your Bravo is going to be lighter than a 20vt, the GT29RSR will be quick spooling, I have heard that it is more progressive than the GT28rs which is very hard hitting, so it might be easier on the clutch, but I suspect that eventually 320+ lb/ft even in your setup will be too much for the Walkers/GTA combo.

Joe

Yes and with the wiring mod.

Just got off the phone with Barbz and he said to map the car until it starts to slip then back it off a bit, He said it should hold 320lb/ft but as they are re-con who knows and depends on how I drive after. He also said if I want more power remove the organic disc and replace it with a paddle disc from Helix which can hold up to 340ft/lb. So I will have a Helix/Walkers combo (Not quite the same as a proper Helix clutch). Then the next weakest link is the rods but I won’t change them as you gotta stop somewhere.

Can’t wait to post my results after mapping.

I would advise anyone looking for clutch to seriously consider the group buy going on as in Heinzsite I would have gone with it.

Thats what he told me too which what i meant by slightly detune it!

I have a walkers paddle driven plate sitting in my garage done around 2k miles, i have yet to bin it just incase..

I have just spoken to PT and i am booked in for monday the 18th

Ross, do you really think it's a good idea to push your luck?

I've been lucky recently tho. *touches trees and tables*

Nah after speaking to barbz, im gonna get the rsr and see how that goes. Then if i want more, go for fully forged.

Ross

Rod snapped and then sliced through the block coming out of both front and back and smashing the oil pump clean through the sump! And set light to the car big time

IIRC 413bhp @ 5500, 390 lb.ft @ 5500. 1.6 bar all the way to 7000 rpm, but basically couldn't force the air through the engine at that level. Cutting the boost to 1.1 bar on next engine only cost me 7bhp and torque curve to 5500 was almost identical

Impressed that anyone would want to see how much power you can run reliably wuth standard internals. The only way you'll know for sure is to break and engine or two! I've done more than my fair share of destruction testing - 4 engines so far, still counting (and two gearboxes, three turbos....). Wouldn't wish that on anyone

a bloody expensive handlin that would be

Fingers crossed if something goes then the block will be OK. Nyssa - I've lost one engine due to poor mapping so I do know how if feels. Who mapped the car to 1.6 bar when the engine could not flow that level of boost? I would have thought that a rod going like that would be more a product of that monster torque than the excess boost?

Hmm I am running almost 1.6 bar boost (all the way to 7000 rpm) on forged pistons only
didnt knew the engine could not flow it?

I think the standard rods are stronger than most people may actually think. I think that the weak point is the rod bolts and it’s a real shame that uprated rod bolts have not been made for the standard rods. My engine is fully balanced and the rods have been shot pended and polished and balanced to absolute zero. It’s a risk I’m willing to take as we all are pushing the coupés limits further and further.

Clear your PM's Ross.

I’ve spoken to JohnS about the standard rods + bolts – he thinks the bolts are the weak point, and given how much knowledge and experience he has with coops I’m inclined to agree!

If you’re going to replace the bolts then you may as well do the rods though – wont be a lot more, and I believe the parts come as a set including the rods and bolts.

Clear yours!!! Lol.

Problem with stnd internals around this range is 2 things.

1. Its russian roulette to when the engine is going to let go, not if.

2. Turning the boost up and changing a turbo, isnt really the best option of gaining usable power. No disrespect to the guys with the figures as they are impressive, but the fact that the gt28r with the 347lb/ft is only getting 319 bhp, shows that his setup is unable to flow higher up the rev range. No doubt that 347lb/ft is a peak and not a constant. I can guarantee that Myself and Subas car has a wider spread of torque and we both have a higher bhp up the rev range.

Ross

Hi Ross ,

Wait until you see the graph of GT28R RR , it is really amasing, from 4600 rpm up to 7000 rpm whole time +300 bhp !!

Although I have peak power much higher, in reality his car is much "drivable" than mine, okay in quarter mile and "Top Speed" I'm faster, but in allday run, his setup is much better . Anyway high (peak) power feels so good... .

- Jari -

Yeah, would be interested to see the graph.

Ross

@ Jari

My question is that these are figures whilst on the RR with wideband, det-can, EGT etc. The reality is you can run any power on the rollers as every thing is constantly monitored. Are you brave enough to run these figure on the real road?

Just to remind you all I did bend all 5 std rods and snapped one (may well have been rod bolts) on std rods with 408BHP/ 400lbs/ft at low boost (1.25 bar). They were properly balanced up to 8500rpm so the issue was that the rods cannot take that power. It did take a fair few miles to happen but if you want to be reliable I would take 15% off the power I had if you want to be safe. I did do a couple of stints with race fuel and an extra 30lbs/ft but to be honest I very much doubt that caused the damage.

Chances are if a rod goes it will take out the block and may also take out the crank and sump with it, or even head so it more or less writes off the engine.

The only other comment I would make is depending on the dyno the readings might be a bit generous. Like if I went to G-Force or Powerstation I could possibly get an extra 30-40BHP

John

Well thats stopping me from doing anything silly.

Ross

The way your 2.4 delivered torque in the low and mid range is very different from a 2 litre therefore I would suggest this is a considerable factor in how you bent your rods! Big torque, low rpms and high gearing are going to truly test the rods to a much greater capacity than high rpms with 40-50lbs/ft less.

P.S. I really think you should try Powerstation... you may be a bit dissapointed though

Is this not on Johns heavily modified 2 litre engine he’s speaking about. Before he went 2.4?

85% of 400lbs of torque is 340lbs which is just about what was said at the top of this thread.

Claudio and Rob at Perfect Touch don't recommend going above 320lbs of torque on standard internals, as they have seen at least 2 engines fail above that. PT have one of the most conservative dynos around so this all seems to make sense.

So, if anyone wants to go beyond these figures, don't be surprised if it all ends in tears!

John ran with standard rods initially as the forged rods weren't available in time for the engine build.

As far as what is safe, I would say it very much depends on how you set up the car and power delivery. The Finnish boys have bigger balls than most of the UK lot and are starting to push the boundaries further and further. I belive Jari has been running big boost i.e. 1.6bar+ and 340-360lbs/ft, for well over a year now on standard internals. As a tuning company you would give conservative advice unless you really felt confident but as individuals we can go for broke. If you happen to get some blowby or break a rod then you can go forged but you could say why spend until it happens... if it happens.

For a FWD car the coop really does like big power so I say go for it

Where's the feckin RR charts

I wanna see tooo!

Ross

I have them also but I don't know how to post

Jamie

I am running 1,5 - 1,6 bar boost for everyday use, but of course dont push it much in the hot summer days... I believe the torque is only around 340 Nm dont know the hp figures either i am guessing 380 - 400

Presumably you mean lb/ft as 340 nm is near about 225lb/ft which is under stnd.

Ross

Oops I meant 440 Nm of course

PS: Wheres my pic h2ypr?

here's the Graphs:

http://i11.photobucket.com/albums/a198/suba11/GT28RSgraph.jpg

http://i11.photobucket.com/albums/a198/suba11/GT28Rgraph.jpg

http://i11.photobucket.com/albums/a198/suba11/CoupeGT3071Rpower.jpg

John - would the issue there have been the high rev limit rather than the torque? Doesn't the stress on the rods increase at a massive rate when you go that high on the rev limit? I'm sure that the torque would also be a factor though!

Why don't the power and torque plots cross at 5,250rpm?

As far as I can remember, they MUST cross at this point, regardless of the scale of measurement (KW & Nm or BHP and lb-ft)

It looks like the graphs are being moved around for some reason

They're not on the same scale ...

I've heard this aswell. Those graphs are very difficult to read. Peak torque on the first one is 390nm? Thats about 284lb/ft? Second one is 460nm? Thats around 335lb/ft? Unless im working it out wrong?

Ross

Thats a club site. Checked another site and its multiply by 0.73.

Ross

Dude u changed ur post - just say u were wrong!

Wasnt denying i was wrong. Sorry if it came across that way. Check my edit reason. I got my calculations wrong. I thought it was 0.66 but its 0.73. That site does nearer 0.75.

Ross

Hi TurboJ,

Short and simply answer, yes . Like I explained my Top Speed run was made with excat the same setup and all the gears through with full throttle . There was only one Sierra Cosworth (+650 bhp) with 281 km/h and Porsche Turbo (997) with 271 km/h ahead me, for example Audi RS6 stayed well behind me with 245 km/h, so I guess I have used at least amount of power + torque as was given in RR .

Also like Flea explained, I have used +350 lb-ft already over two years. My first high power RR was with GT28RS (335 bhp and 376 lb-ft). This graph was also posted to the Forum.

Think if some tuner says, that it is safe to run with that amount of power / torque and you crash yuor engine. Who is to blame? That is why they always answer you so that they can be quite sure, that with given values your engine stands.
At least this is how I see it.

I don't have any clear answer to that, why my engine stands (so far )or my friends engines stand these kind of figures, but we beleive to know what we are doing .

About the graphs, they don't cross because of the scaling, left hand you have power in kW and in right hand you have torque in Nm (1 lb-ft is about 1.356 Nm), so by dividing the Nm values with 1.356, you should receive the lb-ft torque value.

- Jari -

@Suba - I never used to go over 7k with std rods because of the rod bolt potential problem so my issues were not related to that. Anyway, I asked Arrow rods for some consultancy on the 2.0 std rod and they told me it was definitely not good for 400BHP and 400lbs/ft.

The torque delivery of the 2.4 is very different but only because you chuck such large turbos on a 2.0. I've seen a 2.0 that made 350lbs/ft torque at approx. 3200rpm for instance. Although it did break a rod

Also on my 2.4 the torque came in pretty gently as is common with larger turbos.

@Flea - I've been to powerstation!

Nice to see the various power graphs Jari How do you feel about your setup at the moment? It looks just about spot on for the drag strip but is it ok to drive around town?

@John, let's be seeing your graph then

I can get around 300lb/ft at that rpm aswell.

Ross

Who are they or are they staying anonymous?

It was years ago My car made 227BHP on Powerstation rollers and 189BHP on Owen Devs rollers. Same setup and within 3-4 weeks of each other.

Reason I wouldn't go back to Powerstation is my car was overheating on their dyno due to their hairdryer fan and they still did about 6-7 power runs on it. Even tried to spray my intercooler knowing their fan wasn't up to the job like cowboys. I think theres a fair few people on the forum who will remember that.

Ahh, that's different to what they have now. The fans are very powerful all within a totally enclosed cell coupled with a new dyno. There have been plenty of dyno days there since and all making expected or lower power With my old setup I was consistently running 360bhp there the same as PTS. As for Owen Devs, well last time Barbz was there he got 440bhp with a boost leak... on the road I was pulling a bit at the top end so make of that what you will

Powerstation are the leading Subaru tuners and won Time Attack, they certainly are a very professional outfit these days!

The most impressive graph seems to be the RS ... decent low down torque and top end - what other mods was he running?

Here is a comparison of the three Finnish coupés

Torque

BHP

Discuss!

looking at those graphs, you'd have to say the least powerful car would probably be the quickest on some really twisty roads

Interesting comparison flea.

Can you add in sheiks mines and subas to the torque graph?

Ross

@Flea - yes completely different to what it was.

Hi Flea,

These are good graphs .

And yes, the GT28R is most propably to best setup for driving o twisty roads . Ok, it depends on how twisty they are...
When I and my friend with that GT28R turbo came back from Top Speed competition, there were a road section, which is very twisty. We drove it "quite" fast and hard and there were many part in the road where I should change to 2nd gear, but I was affraid to loose the grip. Because also with 3rd gear I was loosing the grip in high revs. My friend could easily drive it with 3rd gear. All in all I had to drive harder than my friend, just because of the lost of low down torque , but in straigh sections... .

Flea, my setup is quite comfortable and easy to drive "normally", but I have to remember to keep the rev's above 3000 rpm, if I want to be "awake" .

One very important thing in Coupe, look my graph! After 3000 rpm power drops dramatically, this is the reason for intake cam to move that 18 degrees backwards! With this turbo it is first time to see clearly.
Now I will "fix" the intake cam to "sharp" position to avoid that power drop. Maybe I gain also something .

- Jari

PS. Tomorrow quarter mile run in very rough surface, I'm going to try the Hoosier once again. Either way, new record or clutch totally destroyed . This is life...

Jari,

Can you send me an e-mail at fccuk@chorus.pp.se? I get an out of office-reply on you adress