cam and heads

[CantZme]

looking for about 375whp...i searched and found nothing when looking for dyno numbers on an l28et in this range. As of this moment i have a megasquirted l28et with a t3/t4 on a stock motor with 440cc inj. and a wideband...3 in. ehx, fuel rail...all the goodies. My real question is "can i reach 375whp with stock heads(slightly ported), a conservative cam, and ported stock manifolds with a 60mmtb port matched to the head and intake mani.? At 20psi+ with some good dyno tuning i think this should be feasable, but i dont really have any experience with the l28et at those boost levels. Currently running 11psi off a perrin ebcs with a rough tune(probably around 210whp give or take) as i have beaten new s4's and e46 m3's. Dyno numbers and graphs would be appreciated.

[OlderThanMe]

Well since the head is the major limiting factor on any L series engine I would say no. Maybe 300-325 but you really need some cylinder head work to open up the flow.The stock intake and exhaust limit you to 400hp so that is really asking a lot for 375 with a mostly "stock" head.

my 2 cents...

[spork]

I suppose alot of it depnds on the exact T3/T4 turbo you're running. With the correct setup, yes, it can be done....but I'm not sure what you mean by a conservative cam...is it stock, or not? Anyways, you're probably going to be getting close to 30psi...and thats a lot to ask for on most hybrid turbos. Better figure on race gas, and getting your timing curve down just right. If you spent a little money to have the head ported it would help a lot, butyou'll have several things to upgrade once you want to get any more power than that goal (cam, turbo, port work, etc.) All that said, I hope your tuning skills are good, because at that power level on a stock engine, there is absolutely no room for mistakes. All of this is also assuming your bottom end is in excellent mechanical condition.

[dapiper]

Need cam that peaks at 6K RPM and turbo to supply air efficiently above 70% flow map. The rest you already have. Can get 375 at 17 psi

[Doug71zt]

I am running a stock bottom end with stock cam in a P90a. My trap speed says that I am making more than 400 hp at 21 psi with around 98 octane in the tank. I have run this combo for more than 4 years now, refining the tuning. I seem to be at a bit of a plateau power-wise now, the car won't run any faster than 123.9, shifting at 5800. I think that there are a number of things that are limiting me here - turbine flow, head and manifold flows, and possibly the T04E 60 trim is out of air.

 

The thread discussing it is here:

 

http://forums.hybridz.org/showthread.php?t=112403

 

I'm running stock pistons also.

 

Doug

[CantZme]

so if i get my p90a ported well and i clean up my intake and exhaust ports, unshroud my valves(maybe i'll send it out to brusch), get a mild cam(one that peaks close to redline{6500}) and maybe upgrade to a holset hx40 (externally wastegated) do u think 375whp is in my reach with h2o inj.+pump gas, 20psi and good tuning?

[z-ya]

You can easily get 325WHP on a stock long block with absolutely no head work. You need a T3/T4 with at least a stage 3 turbine wheel. The other important thing is engine management and a good intercooler. And lastly, time on the dyno to get a good tune. I've tuned a number of stock L28ET long blocks and produced 325WHP on 13psi of boost. The remaining 50HP you are looking for is going to cost you lots of time and money, and in the end it's just bragging rights. You will also loose some drivability on the street, and proabably increase the amount of lag in the system.

 

Start with a 325WHP goal, and measure the smile on your face. Then decide if the remaining 50HP is worth the effort.