Power Limit on Standard Internals(Cosworth YB)?
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Power Limit on Standard Internals(Cosworth YB)?
What sort of power could you have an engine from say a sapph Cosworth running at on standard internals before it would be classed as unsafe?
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I am VERY interested in any discussion about how much power and how, can be got out of standard compression. When I had my engine rebuilt, I regretted staying with standard compression, because I thought I was limited to 400bhp. Am I wrong?
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#10
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In terms of good driveable power, on standard cams etc still, I would say low 400s on a GT3071 is the best power you will get whilst still being nice to drive.
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Yes, I'd want it do be driveable as opposed to making a peak figure. I don't actually have a Cosworth, I was just curious, although I'm looking at building a track day car soon and a Cosworth is one of the possibilities.
The other is building a classic shape Impreza with the Newage running gear, and they are something I'm fairly familiar with, hence asking this question on here.
The other is building a classic shape Impreza with the Newage running gear, and they are something I'm fairly familiar with, hence asking this question on here.
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Yes, I'd want it do be driveable as opposed to making a peak figure. I don't actually have a Cosworth, I was just curious, although I'm looking at building a track day car soon and a Cosworth is one of the possibilities.
The other is building a classic shape Impreza with the Newage running gear, and they are something I'm fairly familiar with, hence asking this question on here.
The other is building a classic shape Impreza with the Newage running gear, and they are something I'm fairly familiar with, hence asking this question on here.
Just look at the rear suspension setup on the two cars!
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Well I already know that I could have a 400bhp Impreza which I could drive to and from trackdays/events, it would be that reliable when done right. So maybe it is the better option? The whole reason behind going for Newage running gear would be for strength/reliability, as the drivetrain is well known to be able to stand up to 500bhp, whereas the Classic drivetrain is the complete opposite: soft as shite!
Last edited by Alan_D; 15-08-2009 at 02:01 PM.
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#30
std engine with just bolt ons...i wouldnt go over 400 bhp otherwise it will be problematic...a ported head at this level only allows for bhp for less boost...a bd 14 inlet can achieve 500ish with the right bits after 500 bhp i would always use proper forged pistons..mahles always go out of shape quick much over 500bhp...
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#35
Well I already know that I could have a 400bhp Impreza which I could drive to and from trackdays/events, it would be that reliable when done right. So maybe it is the better option? The whole reason behind going for Newage running gear would be for strength/reliability, as the drivetrain is well known to be able to stand up to 500bhp, whereas the Classic drivetrain is the complete opposite: soft as shite!
Unless its a new model short motor ( ie STI8 or bove ), 400bhp on a SUbaru bottom end is a ticking time bomb especially with track use.
The conrods in the std engine are crap, although the later STI rods are much better. Pistons whether forged STI types or cast will handle 400bhp fine if tuned correctly.
If its a new model STI car you have with 6speed box etc...then with a couple of bolt on bits, you'll easily see a reliable 400bhp. Maybe even about 450bhp with the right turbo at say 1.6/1.7bar
One of Lateral's MD321T's would get you there, or for faster spool aim for the MD321H and slightly less power.
It'll go well, handle well, and have an almost unbreakable drivetrain.
Re Cossie.
They've a steel crank, steel rods, and good forged pistons. Head sealing aside....no reason why you couldnt ram a load of boost into one with a big lower.
I seen one in Malta just scraping 10s runs, totally standard engine ( with studs and head gasket ) with a T66 bolted to it running about 40psi lol ( along with other supporting bolt on mods of course )
Seemed to work fine for him.
Last edited by stevieturbo; 15-08-2009 at 10:19 PM.
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Re Subaru.
Unless its a new model short motor ( ie STI8 or bove ), 400bhp on a SUbaru bottom end is a ticking time bomb especially with track use.
The conrods in the std engine are crap, although the later STI rods are much better. Pistons whether forged STI types or cast will handle 400bhp fine if tuned correctly.
Re Cossie.
They've a steel crank, steel rods, and good forged pistons. Head sealing aside....no reason why you couldnt ram a load of boost into one with a big lower.
I seen one in Malta just scraping 10s runs, totally standard engine ( with studs and head gasket ) with a T66 bolted to it running about 40psi lol ( along with other supporting bolt on mods of course )
Seemed to work fine for him.
Unless its a new model short motor ( ie STI8 or bove ), 400bhp on a SUbaru bottom end is a ticking time bomb especially with track use.
The conrods in the std engine are crap, although the later STI rods are much better. Pistons whether forged STI types or cast will handle 400bhp fine if tuned correctly.
Re Cossie.
They've a steel crank, steel rods, and good forged pistons. Head sealing aside....no reason why you couldnt ram a load of boost into one with a big lower.
I seen one in Malta just scraping 10s runs, totally standard engine ( with studs and head gasket ) with a T66 bolted to it running about 40psi lol ( along with other supporting bolt on mods of course )
Seemed to work fine for him.
Regarding the standard internals: Andy Forrest ran 440bhp on a 95 WRX years ago with standard internals. He used to drive to and from events. He will be doing all my mapping, and giving all advice should I go down the Subaru route again, so I am not concerned with that.
I would be interested in a Focus Cosworth conversion though. I have had a few road going Focus' now and think the handling is spot on, but what concerns me is how they will handle with rear or 4wd, as obviously they aren't designed for that?
#37
He may have done so...but it wasnt a customers car, and he wasnt concerned about breakages.
old rods on standard engines have failed at standard power with abusive drivers. It simply isnt worth the risk pushing them too hard, especially if its a track car. The std rods are crap.
"Handling" is an individual assessment.
A well built and designed car would go very fast in 4wd trim. Less so in 2wd obviously.
old rods on standard engines have failed at standard power with abusive drivers. It simply isnt worth the risk pushing them too hard, especially if its a track car. The std rods are crap.
"Handling" is an individual assessment.
A well built and designed car would go very fast in 4wd trim. Less so in 2wd obviously.
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He may have done so...but it wasnt a customers car, and he wasnt concerned about breakages.
old rods on standard engines have failed at standard power with abusive drivers. It simply isnt worth the risk pushing them too hard, especially if its a track car. The std rods are crap.
"Handling" is an individual assessment.
A well built and designed car would go very fast in 4wd trim. Less so in 2wd obviously.
old rods on standard engines have failed at standard power with abusive drivers. It simply isnt worth the risk pushing them too hard, especially if its a track car. The std rods are crap.
"Handling" is an individual assessment.
A well built and designed car would go very fast in 4wd trim. Less so in 2wd obviously.
To be honest I'd be totally confident about running an Impreza engine on standard internals up to 400bhp if it was mapped by a top mapper. Plenty of Subaru engines have failed because they are played about with by amateurs! The standard rods might be crap(in your opinion), but I would think the failures you talk about would invlove some underlying cause. If not, then it's just bad luck. But I have used a UK Turbo engine at 270bhp(so over 50bhp more than standard) like a race engine for about 20000 miles and it didn't bat an eyelid.
#39
You just need to ask around.
Classic rods are crap that is fact, not just my opinion, and Ive seen them fail on totally standard cars, rod life has little to do with mapping. Its the same rods used on the EJ18, 20, 22 etc whether normally aspirated or turbocharged.
A friend also has a std UK 2.0 running about 350, and has some 160k miles on it now. So they can be reliable too...but it cant be gauranteed.
Classic rods are crap that is fact, not just my opinion, and Ive seen them fail on totally standard cars, rod life has little to do with mapping. Its the same rods used on the EJ18, 20, 22 etc whether normally aspirated or turbocharged.
A friend also has a std UK 2.0 running about 350, and has some 160k miles on it now. So they can be reliable too...but it cant be gauranteed.
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I don't need to ask around though, as I am 100% confident about having an Impreza mapped for more than standard power on standard internals. I have never even thought of the rods as being an issue, and Andy didn't mention that either strangely enough?? I take it you are familiar with what he does? He is a professional, probably one of the best, if not the best at what he does in Europe.
I think we'll have to agree to disagree on this one, as this thread has now gone totally off topic.
I think we'll have to agree to disagree on this one, as this thread has now gone totally off topic.
Last edited by Alan_D; 15-08-2009 at 11:25 PM.