16V 2.5L head/cams on 951 bottom end?
03-03-2013, 02:56 PM
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16V 2.5L head/cams on 951 bottom end?
Looking fro some info on a race-only 2.5L setup...
I currently run a 316hp @ rearwheels, 16 psi boost, pauter rods, afm, chips, K26/8, Lindsey gate...
Looking to see if I can make more power with the 2.5 16V head, cams and exhaust manifold/header...
I currently run a 316hp @ rearwheels, 16 psi boost, pauter rods, afm, chips, K26/8, Lindsey gate...
Looking to see if I can make more power with the 2.5 16V head, cams and exhaust manifold/header...
03-03-2013, 03:44 PM
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You will probbably get more power with a 16 valve head and better powerband to the right.
However it will be very expensive and allot of fabrication needed .
8v Intake manifioild wont fit on a 16v HEAD. intake ports are oval and different "turbo manifoild must be welded\modyfied" to fit the HEAD
8v Exhaust manifoild wont fit on the 16v HEAD. flanges are different "must be welded\modyfied"
Pistons will have to be changed or the stock 951 pistons must be machined for 4 valves.
Lifters and exhaust valves in the head should be upgraded "sodium valves" and stiffer valve springs.
stock 16v cams may be used
For a all out track car it would also make sense to rebuild and upgrade the cam chaindrive (should be done).
Or even convert to a twin cam gear system for even better reliability and ajustment.
With all that work for not that much of an inprovement "in my eyes" compared to price. I would rather select a bigger an better flowing turbo and do other modifications to the engine.
Since this is a track car you wont care so much for turbo lag and a bigger and better flowing turbo would take you further .. But the stock AFM will limit what you can do .
A good cam for a 8v head will also shift the powerband to were you want it and allow more power to be made in higher rpms.
Only reason i see for having a 2,5l 16v engine is if 1. you have done everything else or 2. have a insane budget.
If 2. why stop there dry sump it modify the 16v head for high rpms +\- 9000 rpm.
And choose custom cams, better turbo and better tuning.
If i were you ditch the AFM and chips: Get either a REAL maf like a Vitesse or M-Tune or a standalone ems. The afm cant handle much more than what you output now. Then maybe a differnt turbo "if needed".
Bump the turbo pressure to 18psi or run racefuel and 22psi.
However it will be very expensive and allot of fabrication needed .
8v Intake manifioild wont fit on a 16v HEAD. intake ports are oval and different "turbo manifoild must be welded\modyfied" to fit the HEAD
8v Exhaust manifoild wont fit on the 16v HEAD. flanges are different "must be welded\modyfied"
Pistons will have to be changed or the stock 951 pistons must be machined for 4 valves.
Lifters and exhaust valves in the head should be upgraded "sodium valves" and stiffer valve springs.
stock 16v cams may be used
For a all out track car it would also make sense to rebuild and upgrade the cam chaindrive (should be done).
Or even convert to a twin cam gear system for even better reliability and ajustment.
With all that work for not that much of an inprovement "in my eyes" compared to price. I would rather select a bigger an better flowing turbo and do other modifications to the engine.
Since this is a track car you wont care so much for turbo lag and a bigger and better flowing turbo would take you further .. But the stock AFM will limit what you can do .
A good cam for a 8v head will also shift the powerband to were you want it and allow more power to be made in higher rpms.
Only reason i see for having a 2,5l 16v engine is if 1. you have done everything else or 2. have a insane budget.
If 2. why stop there dry sump it modify the 16v head for high rpms +\- 9000 rpm.
And choose custom cams, better turbo and better tuning.
If i were you ditch the AFM and chips: Get either a REAL maf like a Vitesse or M-Tune or a standalone ems. The afm cant handle much more than what you output now. Then maybe a differnt turbo "if needed".
Bump the turbo pressure to 18psi or run racefuel and 22psi.
03-03-2013, 04:18 PM
#4
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If you don't plan on changing the the turbo, you won't gain much or anything with a 16v head if you keep the k26/8
If you go for high rpm you would want to change R&P gears to the S2 ones
With a good turbo... If you get a descent head with a matching cam you can get a very good power band.
If you go for high rpm you would want to change R&P gears to the S2 ones
With a good turbo... If you get a descent head with a matching cam you can get a very good power band.
