is 400 whp too much to ask?
10-01-08, 02:00 PM
#1
stupid n/a drifter kid
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is 400 whp too much to ask?
seriously! What all needs to be done to get 400 to the ground on a s4 tII? Other than the obvious rebuild and porting? Like what trim turbo and injector sizing! Things of that nature!
10-01-08, 04:26 PM
#6
Shouldn't need it for sub 500whp. Sure, you can do it, but its not a requirement. However getting everything else spot on is.
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10-01-08, 05:26 PM
#8
don't get freaked out by people who have never even gotten close to that power level. The s4 motor can do it, on stock ports, stock irons, etc, if you have good compression. It's been done, talk to J-Rat. And he honestly used an inefficient turbo and manifold to do it (HKS log and journal bearing T61).
Do some searches, but you need 550/1600 (720 primary's would be better), fuel pump, probably an FPR, standalone, ignition upgrade, and on stock ports you will likely need over 15psi to do it, so that means race gas or pump + methanol. If it were me, and I had an s4 motor with good compression, I'd skip the rebuild and go right for it. Get an Aspec 500R kit if you can afford it, or if you want to go cheap use something similar to a divided HKS cast turbo manifold for an FD (might need a spacer to clear the LIM). Then bolt up a Holset HX40 with a 20 cm^2 housing and make your own meth kit. 400whp right there. But the more knowledge and skill you have, the cheaper it will be, because you aren't paying someone to design a kit and do all the fitment etc. The fact that you are making this thread means your best bet is probably an A-spec kit... $10,000 is right, but it COULD be done for less, always depending on what level of modification you're starting with, how much you do yourself, and what kind of deals you get on parts.
And the s4 rear iron isn't as weak as people say in my experience. I have personally detonated the CRAP out of my s4 block and never cracked the iron. I'm talking serious boost spikes on stock turbo (20+psi). I've blown a MAP sensor line off and detonated the crap out of the motor again. Still didn't break the iron. In fact I've broken the insulators off 3 spark plugs from detonation and still haven't cracked a rear iron yet. Now, that being said, I am upgrading to s5 irons on my next build because I might as well.
Do some searches, but you need 550/1600 (720 primary's would be better), fuel pump, probably an FPR, standalone, ignition upgrade, and on stock ports you will likely need over 15psi to do it, so that means race gas or pump + methanol. If it were me, and I had an s4 motor with good compression, I'd skip the rebuild and go right for it. Get an Aspec 500R kit if you can afford it, or if you want to go cheap use something similar to a divided HKS cast turbo manifold for an FD (might need a spacer to clear the LIM). Then bolt up a Holset HX40 with a 20 cm^2 housing and make your own meth kit. 400whp right there. But the more knowledge and skill you have, the cheaper it will be, because you aren't paying someone to design a kit and do all the fitment etc. The fact that you are making this thread means your best bet is probably an A-spec kit... $10,000 is right, but it COULD be done for less, always depending on what level of modification you're starting with, how much you do yourself, and what kind of deals you get on parts.
And the s4 rear iron isn't as weak as people say in my experience. I have personally detonated the CRAP out of my s4 block and never cracked the iron. I'm talking serious boost spikes on stock turbo (20+psi). I've blown a MAP sensor line off and detonated the crap out of the motor again. Still didn't break the iron. In fact I've broken the insulators off 3 spark plugs from detonation and still haven't cracked a rear iron yet. Now, that being said, I am upgrading to s5 irons on my next build because I might as well.
Last edited by arghx; 10-01-08 at 05:29 PM.
10-02-08, 08:01 AM
#13
Like I said the other stuff is far more important at any power level. Plus, at this power level studs are NOT needed. Simple as that.
****, a local buddy's S4 (like I said I've only got experience with that power level on S5 blocks) has been running around 400whp for almost 6 years and 60,000kms. We drove that bitch to florida last spring. It dyno'd over 420whp on a mustang dyno with his (new this year) FJO AI system.
What's been your experience sir?
10-02-08, 10:14 AM
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stupid n/a drifter kid
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yeah the turbo manifold and exhaust and maybe the intake I'm going to be making/modifying my self! But who does good street porting cause I was thinking about getting an agressive street port. And also how much does a street port increase your redline? Or is all that depending on who ports it and how they did it?
10-02-08, 02:33 PM
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You have much reading to do. Search here, single turbo section and www.nopistons.com/forums in their engine building/porting section. Lots of helpful information and people there.
Search first because the info is out there; no need for people to repeat that which has been said a hundred times or more.
Search first because the info is out there; no need for people to repeat that which has been said a hundred times or more.
10-02-08, 04:02 PM
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ive got about the same goals as you. so far i have a rebuilt/ported engine and full standlone with exhaust. allim looking at buying is a turbo setup and alcy injection. also a new rad.
10-02-08, 04:28 PM
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yeah the turbo manifold and exhaust and maybe the intake I'm going to be making/modifying my self! But who does good street porting cause I was thinking about getting an agressive street port. And also how much does a street port increase your redline? Or is all that depending on who ports it and how they did it?
Spec.
10-04-08, 04:55 PM
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I can tell you from experience that S4 plates don't like 400whp. I know of 2 people that lost their motors due to the oil passage near the oil pedestal cracking. Unfortunately I'm one of them. Front plates seem to be a problem too. I'm running new S5 plates on my current build with no issues. They are much beefier where it counts.
Cheaping out the first time forced me to spend almost double what I should have.
Cheaping out the first time forced me to spend almost double what I should have.
Last edited by 3Faced; 10-04-08 at 04:57 PM.
10-04-08, 06:54 PM
#24
10-05-08, 09:17 AM
#25
My old TII 409 WHP
MODS: Street ported S4 Irons w/ S5 internals and S5 housings, 3" turbo back exhaust, Turbonetics 60-1, HKS log manifold, HKS Standard Wastegate, NPR FMIC, 720cc primary / 1680cc secondary injectors, Walbro fuel pump,Aeromotive FPR, Microtech LT8S ECU, Turbonetics MBC, BDC throttle body, 3 MSD 6A ignition boxes
MODS: Street ported S4 Irons w/ S5 internals and S5 housings, 3" turbo back exhaust, Turbonetics 60-1, HKS log manifold, HKS Standard Wastegate, NPR FMIC, 720cc primary / 1680cc secondary injectors, Walbro fuel pump,Aeromotive FPR, Microtech LT8S ECU, Turbonetics MBC, BDC throttle body, 3 MSD 6A ignition boxes