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Re: I was then I wasnt....
[Re: Nigel]
#1393921
25/11/2012 16:54
25/11/2012 16:54
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Joined: Dec 2005
Posts: 4,833 Haslemere, Surrey
Mark_S
Forum is my job
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Forum is my job
Joined: Dec 2005
Posts: 4,833
Haslemere, Surrey
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Nigel, I keep getting tempted by the shiny 3" down-pipe, but always reject it in my mind as it will loose me torque and increase spool up time. Did you not think about the standard smaller down-pipe as better for driving characteristics?
997 C4S
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Re: I was then I wasnt....
[Re: Rudidudi]
#1393932
25/11/2012 17:12
25/11/2012 17:12
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johnnybravoturbo
Unregistered
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johnnybravoturbo
Unregistered
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going to post, then i decided i would...
firstly this isnt a stab at the owners of the 'whats the bhp' topics...
so apart from the 'joy' of having a large bhp engine, why do people get hung up on big bhp engines.
Id rather have a car that has greater average torque throughout the usable rev range, this is a better sign of which car will be more tractable, faster, especially off track, or even on track when a car doesnt have narrow power bands and gearing to suit.
More 'under the curve' beats 'max bhp' everytime. This is exactly the point I try to get across. Usually the less Bhp the quicker the car. For instance a 450 Bhp 2871 will always beat a 500bhp 3076. More tractable linear power for longer duration with less drama. However in the pub you couldn't explain this to anyone and frankly they wouldn't care so you need the power figures. On the road less is quite often more.
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Re: I was then I wasnt....
[Re: Mark_S]
#1393985
25/11/2012 21:07
25/11/2012 21:07
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Joined: Dec 2005
Posts: 17,370 Staffordshire
Nigel
Forum veteran
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Forum veteran
Joined: Dec 2005
Posts: 17,370
Staffordshire
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Nigel, I keep getting tempted by the shiny 3" down-pipe, but always reject it in my mind as it will loose me torque and increase spool up time. Did you not think about the standard smaller down-pipe as better for driving characteristics? The slight loss in torque of a big pipe can be overcome with other measures, such as keeping the exhaust ports in the head small (to increase gas speed) It's probably correct to say that a standard downpipe will give better low-down power characteristics, but it will absolutely kill the top end. I'm not THAT interested in mid-range that I'm prepared to sacrifice 100+bhp at the top - I just wanted to increase the mid-range, rather than add another 50bhp at the top, with no gain elsewhere
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Re: I was then I wasnt....
[Re: Rudidudi]
#1394023
26/11/2012 00:08
26/11/2012 00:08
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Joined: Dec 2005
Posts: 1,673 SW London
Rudidudi
OP
My life on the forum
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OP
My life on the forum
Joined: Dec 2005
Posts: 1,673
SW London
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a smaller downpipe will push the torque lower in the powerband. big downpipes / exhaust will reduce bottom end torque. if you want to be getting big top rpm figures, go big. but big isnt usable until you get into the high rev range... question is - how much time do people spend at 6k rpm? if you do then your engine wont last too long by comparison to a car that delivers more torque lower down average torque in the used rev range, that's the key to a quick street car its all about what is 'under the curve'
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Re: I was then I wasnt....
[Re: ]
#1394029
26/11/2012 02:12
26/11/2012 02:12
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Joined: Feb 2008
Posts: 1,728 London
kj16v
My life on the forum
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My life on the forum
Joined: Feb 2008
Posts: 1,728
London
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going to post, then i decided i would...
firstly this isnt a stab at the owners of the 'whats the bhp' topics...
so apart from the 'joy' of having a large bhp engine, why do people get hung up on big bhp engines.
Id rather have a car that has greater average torque throughout the usable rev range, this is a better sign of which car will be more tractable, faster, especially off track, or even on track when a car doesnt have narrow power bands and gearing to suit.
More 'under the curve' beats 'max bhp' everytime. This is exactly the point I try to get across. Usually the less Bhp the quicker the car. For instance a 450 Bhp 2871 will always beat a 500bhp 3076. More tractable linear power for longer duration with less drama. However in the pub you couldn't explain this to anyone and frankly they wouldn't care so you need the power figures. On the road less is quite often more. There's soooo much more to making a fast car than just making a peak figure on the dyno. Most people understand when you explain to them what makes an actual fast car as opposed to one that just makes pretty dyno graphs (though occasionally some people don't!). People really understand once they've actually driven a genuinely fast car. But until a person has a bit more understanding of what makes a car fast they'll always be under the mistaken impression that bigger bhp always means faster. Whereas in reality it depends on the situation; sometimes more bhp means faster, sometimes it doesn't - sometimes it means quite the opposite Rudidudi, it's obvious you have an understanding of what makes a car fast Having said all that, there's nothing wrong with aiming for the biggest numbers, you just got to know why you're doing it and whether it's best for your particular use.
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Re: I was then I wasnt....
[Re: Rudidudi]
#1394045
26/11/2012 09:00
26/11/2012 09:00
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Biggenz
Unregistered
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Biggenz
Unregistered
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how much time do people spend at 6k rpm? It all depends what you want from the car. I built my car so I could spend my time between 5-8k. And what has been said that a 450bhp car will always be quicker than a 500bhp car is nonsense, sorry JBT. One of my mates has a 400bhp+ setup and I leave him for dead, everytime. There is actually no comparison between the two cars as I took him out in mine and he was stunned at the difference in performance.
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Re: I was then I wasnt....
[Re: ]
#1394051
26/11/2012 09:25
26/11/2012 09:25
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roly
Unregistered
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roly
Unregistered
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On the road less is quite often more. power is nothing without control.
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Re: I was then I wasnt....
[Re: ]
#1394060
26/11/2012 10:13
26/11/2012 10:13
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Barbz
Unregistered
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Barbz
Unregistered
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Displacement all the way.
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Re: I was then I wasnt....
[Re: ]
#1394082
26/11/2012 12:25
26/11/2012 12:25
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Joined: Dec 2005
Posts: 17,370 Staffordshire
Nigel
Forum veteran
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Forum veteran
Joined: Dec 2005
Posts: 17,370
Staffordshire
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And what has been said that a 450bhp car will always be quicker than a 500bhp car is nonsense Well- clearly it won't be "always", but there are many circumstances when a lower power car will be quicker than the big-power car A few years ago, Leighton turned up to Curborough with a new 3076 turbo and hardly got full boost all day. Dave Tanner was also there with his near-standard engined 20vt and proceeded to post FTD There are obviously times when the big power would have triumphed - if our little trackday had been at Silverstone instead of Curborough, I'm sure Leighton's car would have been quickest.
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Re: I was then I wasnt....
[Re: Nigel]
#1394107
26/11/2012 14:19
26/11/2012 14:19
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doug20vt
Unregistered
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doug20vt
Unregistered
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all down to driving style, if you happy to really rev the car then the car with the bigger turbo requiring higher revs will be quicker as it will ultimately produce more power
personally i would rather have the power at more sedate engine speeds allowing me to make quick progress without having to rev the nuts of the car, it's all personal preference though although having a car that didn't start to produce any sort of boost pressure until 4k or so would quickly become tiresome, it's why i don't like type r's, s2000's and the like
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Re: I was then I wasnt....
[Re: Rudidudi]
#1394239
27/11/2012 00:00
27/11/2012 00:00
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Joined: Aug 2010
Posts: 141 East yorkshire
sherlock
On a journey
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On a journey
Joined: Aug 2010
Posts: 141
East yorkshire
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Id rather have a car that has greater average torque throughout the usable rev range, this is a better sign of which car will be more tractable, faster, especially off track, or even on track when a car doesnt have narrow power bands and gearing to suit.
More 'under the curve' beats 'max bhp' everytime.
I would agree, big bhp is good if you want to go fast in a straight line, the downside being it can get tedious waiting for a big turbo to spool on the road - but you can have it both ways! I've been playing with a twin turbo setup, which is spooling up quickly making a useable 210lbft@2750rpm. Not sure on top end power but its alot, was having boost control issues going over 5k at the time I'll post acouple of pics up when I have the chance
Last edited by sherlock; 28/11/2012 14:35. Reason: pics
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Re: I was then I wasnt....
[Re: sherlock]
#1395610
03/12/2012 09:40
03/12/2012 09:40
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Joined: Dec 2005
Posts: 12,296 Sandhurst
Begbie
ex El Presidente
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ex El Presidente
I AM a Coop
Joined: Dec 2005
Posts: 12,296
Sandhurst
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Id rather have a car that has greater average torque throughout the usable rev range, this is a better sign of which car will be more tractable, faster, especially off track, or even on track when a car doesnt have narrow power bands and gearing to suit.
More 'under the curve' beats 'max bhp' everytime.
I would agree, big bhp is good if you want to go fast in a straight line, the downside being it can get tedious waiting for a big turbo to spool on the road - but you can have it both ways! I've been playing with a twin turbo setup, which is spooling up quickly making a useable 210lbft@2750rpm. Not sure on top end power but its alot, was having boost control issues going over 5k at the time I'll post acouple of pics up when I have the chance Wow, over a week and no one has said anything about a TWIN TURBO setup? How have you set it up? Large turbo on the manifold and small turbo at the side? Have you got the exit of the large turbo into the top of the small turbo? I would love to see some more pictures
Your car is Usain Bolt with wellies
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Re: I was then I wasnt....
[Re: Begbie]
#1395622
03/12/2012 10:43
03/12/2012 10:43
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Joined: Feb 2008
Posts: 1,728 London
kj16v
My life on the forum
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My life on the forum
Joined: Feb 2008
Posts: 1,728
London
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Wow, over a week and no one has said anything about a TWIN TURBO setup? lol Didn't even notice anybody had posted! That's some impressive packaging there, Sherlock! Tell us about the pipework!
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Re: I was then I wasnt....
[Re: kj16v]
#1395623
03/12/2012 10:46
03/12/2012 10:46
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RICHB
Unregistered
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RICHB
Unregistered
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Wow, that engine bay must get mega hot ....is that the intercooler where the air box normally is ?
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Re: I was then I wasnt....
[Re: Rudidudi]
#1395625
03/12/2012 10:56
03/12/2012 10:56
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Marco20ValveT
Unregistered
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Marco20ValveT
Unregistered
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SLAP ME IN THE FACE WITH A BRICK!! we need more info! this is a coupe first no? Brilliant work!!
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Re: I was then I wasnt....
[Re: Rudidudi]
#1395639
03/12/2012 11:25
03/12/2012 11:25
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Turboman87
Unregistered
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Turboman87
Unregistered
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Very interesting! How can I miss this?
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Re: I was then I wasnt....
[Re: ]
#1395640
03/12/2012 11:26
03/12/2012 11:26
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RICHB
Unregistered
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RICHB
Unregistered
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Im hoping its a small turbo for quick spool, leading into a bigger turbo for top end power....more info pleeease
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Re: I was then I wasnt....
[Re: Rudidudi]
#1395651
03/12/2012 12:16
03/12/2012 12:16
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Nobby
Unregistered
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Nobby
Unregistered
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Nice! More pics/explaination please.
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Re: I was then I wasnt....
[Re: Begbie]
#1395775
03/12/2012 20:47
03/12/2012 20:47
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Joined: Aug 2010
Posts: 141 East yorkshire
sherlock
On a journey
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On a journey
Joined: Aug 2010
Posts: 141
East yorkshire
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Just want to say I really do agree with the original post. Its great running a big turbo if you happen to be in a hurry but as a everyday proposition it spoils the car imo. For example driving in 6th gear at 70 mph putting your foot down and nothing happening is a joke for a car with a 2litre petrol engine Id rather have a car that has greater average torque throughout the usable rev range, this is a better sign of which car will be more tractable, faster, especially off track, or even on track when a car doesnt have narrow power bands and gearing to suit.
More 'under the curve' beats 'max bhp' everytime.
I would agree, big bhp is good if you want to go fast in a straight line, the downside being it can get tedious waiting for a big turbo to spool on the road - but you can have it both ways! I've been playing with a twin turbo setup, which is spooling up quickly making a useable 210lbft@2750rpm. Not sure on top end power but its alot, was having boost control issues going over 5k at the time I'll post acouple of pics up when I have the chance Wow, over a week and no one has said anything about a TWIN TURBO setup? How have you set it up? Large turbo on the manifold and small turbo at the side? Have you got the exit of the large turbo into the top of the small turbo? I would love to see some more pictures It’s a compound setup – It can and I have been running it sequentially but as it is now its compounding the boost. The small turbo is on the manifold feeding its exhaust into the big turbo’s turbine housing. There’s two 46mm external wastegates one on the manifold the other taken off the back of the small turbo’s turbine housing, they both also feed into the big turbo’s turbine housing. The big turbo feeds compressed air into small turbo’s inlet. That’s it really nothing too complicated, the hardest part is getting everything to fit. Its nothing new in the way its setup but it’s the kind of thing your more liking to find on a diesel engine with it being capable of massive amounts of boost Phill
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Re: I was then I wasnt....
[Re: sherlock]
#1395780
03/12/2012 20:57
03/12/2012 20:57
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tim42
Unregistered
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tim42
Unregistered
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This sounds epic.... Good stuff Phill - you've really atarted the boys off now. Mind you, if I'm doing 70mph on the motorway in 6th I drop into 5th and something happens
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Re: I was then I wasnt....
[Re: ]
#1395782
03/12/2012 20:58
03/12/2012 20:58
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Joined: Aug 2010
Posts: 141 East yorkshire
sherlock
On a journey
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On a journey
Joined: Aug 2010
Posts: 141
East yorkshire
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Wow, that engine bay must get mega hot ....is that the intercooler where the air box normally is ? Yeah, the heat does soak in abit when your stuck in traffic think part of the problem is no heat shield on the manifold. Its running two intercoolers, the one in the pic is the standard one turned upside down
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Re: I was then I wasnt....
[Re: Rudidudi]
#1395793
03/12/2012 21:40
03/12/2012 21:40
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gscozzari
Unregistered
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gscozzari
Unregistered
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Re: I was then I wasnt....
[Re: Rudidudi]
#1395798
03/12/2012 22:04
03/12/2012 22:04
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Joined: Oct 2008
Posts: 6,783 In the coupe.
magooagain
Club Member 259
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Club Member 259
Forum is my life
Joined: Oct 2008
Posts: 6,783
In the coupe.
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Im trying to get my head around how the turbo from the manifold and the exit from the final turbo to downpipe looks. Or am i not understanding the set up ?
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