adam1803

iTrader: (65)

I plan on running 15psi max, only at the track probably so running race gas won't be a problem. For the street i'll be running 10-12psi max. I have been planning on re-using my gt2-3 cam for it but im not 100% on that yet. My IAT's at the moment with the 60-1 turbo at 6 psi are only a few degrees above ambient but i will be switching to a gt67. Hopefully the better efficiency of the gt67 will keep IAT's fairly low.

1SlowHoe

iTrader: (28)

Everybody is doing a 370ci lately.

Mine will be about 8.7:1 and eventually putting 12-15psi at it.

8ALTNG

iTrader: (1)

I think that with a cr of 8.5:1, you should be able to run 15# no problem. That is assuming that you are going to run your FMIC and maybe throw 4-5 gals of a 112 octaine race fuel in there when you go race. I ran 15# on the street, on 93 pump with the 4.8/67mm combo. My cr was right at 8.3:1 I believe.

parish8

iTrader: (6)

everyones set up is diferent. with my current motor 408/8.7cr, very efficent turbos and large intercooler i can only run 11psi on pump gas. thats at 15deg. sure if i droped the timing down to 5deg it might goto 15psi. who knows it might even make more power with that setting.

i wouldn't try and run 15psi on any of these motors without race fuel or meth. that being said it still doesn't answer your question about cr. does anyone know what just that one change will feel like? most people up their cubes and toss in a bigger cam along with cr changes so knowing what just the change in cr will feel like is hard to say.

8ALTNG

iTrader: (1)

I agree whit Jim. There are many factors at play here. I think that you could find some good info on this over on LS1Tech, in the FI section or even in the regular ls1 engine section. Lots of guys have run 370 combos over there.

adam1803

iTrader: (65)

well i just ordered my pistons, i got diamonds with 15cc dish. It should put my CR right about 8.7 and i can tweak it from there depending on which gaskets i use. Should be fairly good on low end still and be boost friendly.

8ALTNG

iTrader: (1)

Nice choise Adam

fullthrottledan

iTrader: (2)

ive got a 370 as well, with a dynamic comp of 9.46:1. Its very hard to see 15psi for me. no way on pump gas. I have tons of low end, which is nice with the 6 speed and 3.42 gears. I do have a descent size intercooler (31x12x3 air to air) and my intake temps have been pretty low. I dont plan to run a ton of boost, just about 12psi or so. In order not to detonate i have to keep timing really low as well.

TurboBerserker

iTrader: (1)

8.7:1 is a good choice IMO. Jim runs that, I run 8.65:1 (probably only different due to the gaskets we use or minor differences in the pistons).

I'd still look at meth -- for piece of mind if nothing else. Plus you will be able to run more timing regardless of what boost level you settle on (and will be able to run more boost with meth anyway).

adam1803

iTrader: (65)

I've thought about using meth before, but im just not sure i want to have to worry about it not spraying or running low and then blowing up my motor.