what kind of power are you turbo guys putting down. i am looking at a 76mm turbo on a 370ci motor, is 10.2:1 rato and i can get it lower, im looking in to a new 408 9.1:1 cr but im a little far off for that.


looking to go for 700+rwhp,


thanks Josh

 

There are a lot of units that will make the power on a 370. A Turbonetics 78 with a F1 turbine wheel and a 1.15 a/r would work good. Should make 800whp on that unit.

If you are planing on a 408 down the road I would look into something with a better exhaust side though. At minimum a PT88, better would be a Garrett budget 88 or a GT47-88.

 

your going to be limited on your boost numbers by your compression ratio with the current motor. low 10's:1 is great on a low boost street motor for throttle responce and off idle power, youre not really talking about the boost capability you need for that kind of rwhp until your in the low 9s like you are looking for in your big inch build...

but I'd imagine a 10.2:1 370 with a good 76mm and .96 a/r exhaust side would make an awesome street setup!!! all the tq youd ever need and properly tuned I'd say you could probably run up to around 9lbs without a problem.

 

I have a 370 10.1 compression engine and a gt-67. It is nice on the street, and I can hit 10 psi pretty easy with a little meth and no kr. Unfortunately, my meth system died before I got to crank it up to find the limits of timing/boost before I decided to replace the gt-67 sts with a front mount 75mm.

If it were me and I could do it over, I would look for the turbo you will actually use, see what pressure ratio it is most efficient, and build the engine to suite.

 

so a 10.1 motor and a 76mm with a .96ar would do the trick on the street. im looking a good street truck. i ran a 7.75 with a sts t70mm and did not spool off the line at all. loved it. but the motor went 2 day after. then i went to a 112hh and liked it for a little bit, now i have this Nitruos set up and ran a 8.0 last night but i need and want to be back down in the low to mid 7s.


just lookin to make a good street truck and at the track sometime.

thanks for all the help

 

That 76 will definitely get you what you're looking for, just be mindful of your timing with that much compression. Detonation is reached way easier... And please, don't put that STS back on (and I'm not trying to start "the debate" again) just put it up front where it belongs and run it...

 

10 4 thanks for the help... im going to see what i can do with KB....i like the kit he makes and i have done biz in the past with him, just a good stand up guy!

 

76 can get you there on a 370. No real need for the 408. Compression and boost just depends. In the past is was low compression and lots of boost. Main reason lots of heat with lots of boost. Keeping your air temps down with a good intercooler, and water/meth or even E85, 10-1 is not that hi.
Everything is a trade off, higher heat, less timing less power.
low on compression on street trucks, it can kill gas milage.
Heres Stock 4.8's dyno sheet. Got him into the mid 10's...