a very similar setup to my 408, 8.5:1 CR, 225 ETP heads, 230's/230's cam made 400+rwhp through a M6 trans. I think those numbers are low, but a turbo will take care of that.

 

Lets assume the 10 PSI gives you 200 rwhp and 75 shot gives you 100. 600 minus 300 gives you 300 which is still better than my numbers and your engine is only a little higher cr (9.2 vs 8.7) and 30 ci smaller.

If my auto has a 20% drive train loss vs your M6's of say 10% that is only a 10% difference then factor in the 17% lower numbers from this dyno and I am still low. Your numbers would be 450 crank hp - 20%(auto drive train loss) - 17%(dyno) = 300rwhp.

Something has to be wrong with my setup I just don't know what. I am thinking I am down between 50-100 hp from where it should be.

 

Those dynos usually read way low, just run it at the track ASAP befor you make any rash decisions. Track #'s are all that matters any way. 15PSI reliably on 9.5:1 is pushing it, without race gas, or E85. About 12 is all I would go on 91. If you want 15PSI I keep it at 9 or below.

 

im 9.2 to 1 and i didnt have any issues running 91 with 15 psi.


i did how ever r un meth , and max 17-18 timing in most areas

 

me and justin were talking about it and I think your cam and your cr is really holding you back. I had a much bigger cam and full exhaust and i could only run a 13.5 at the track which is not much better than my old 6.0.

How long before you put the sts on it? if its going to be a while then i would get some stock zo6 or ls2 heads. and that will bump up the cr to the 9s.

 

I looked at an online cr calculator and got the following results:

Current setup:
WCCH P&P 6.0 heads(73.5 cc) = 8.7 cr

Swapping Heads to:
Stock LS7(70 cc) = 9.03 cr
P&P LS6(69 cc) = 9.10 cr
Edelbrock 245/215(66 cc) = 9.35 cr
AFR 225(62 cc) = 9.69 cr

Also, changing to a Z06 or similar cam for now might be good. Plus I have head that the Z06 cam is ok for boost.

 

I wouldn't go with a smaller cam at all. If anything throw the sts on it and see how its going to do. how big of a stall are you running?

 

It is a 2800 stall from Edge Racing.

 

Not sure why anyone would care what their motor makes without the FI option if it was built for that. That is pretty much asking to let yourself down. If you figure out all the things that will be happening in the design of your plan with the FI, then most of those things change when you run it without the FI. So dont get so down on yourself. Only be disapointed if your combo does not do well once you have put the FI on it. Then you can compare to what your goals where.

I would not expect some of the motors I built to make much power without their turbos on them, but once you put some boost on it, they make crazy power.

Rick

 

i have to speak on this subject. i would want a strong NA motor before i boosted it. the more power you make NA the more power you will make on boost. plan and simple. what your motor makes at 1 bar is a good number to use what your motor will make at 2 bar that is doubled. if his motor only makes 250 rwhp at 1 bar hes looking at close to 500 at 14.7lbs. thats not very impressive. thats right around what thunder550 makes. now he wants to run 20 psi thats only going to net him 585 rwhp roughly....thats not much hp out of a 408 when some 4.8s and 5.3s are seeing those numbers..... i see it make the most you possibly cant NA then add boost. if you can produce
4xx na that is a good base for making close to 1k rwhp when you crank it. at the 250rwhp level hes at now i would expect that out of a baby motor...