quik01ss

iTrader: (24)

-After melting a piston this week and scoring the cylinder all up getting a

new short block thats forged and balanced.

-What compression should i run when im going to be using SpeedINC's TU1

Cam and stock 241 heads looking for around 500 550 hp/tq again and not

going over 10psi with this cam.


*Motor comes in these ratios: 8.5:1, 9.0:1, 9.5:1, 10.5:1, and 11.0:1

COD02SS

8.5:1.. **** even 8:1 if you can

trans2000am

iTrader: (49)

all depends on how many pounds you wanna push and say 9.5 to 1 would be fine

quik01ss

iTrader: (24)

hmmm... ive seen a guy on here with TRT Turbo's cam and made 500 or so

with just 6 or 7 psi i dont know the specs on that cam as if it were the same

or close to SpeedINC's cam..

So maybe ill get TRT's cam and say run 6.5 to 7.5 psi. isnt if you go to low of

compression the car will fell like crap out of boost? Correct me if im wrong.

trans2000am

iTrader: (49)

yea car out of boost with low compression motor will feel like crap.

COD02SS

Then run more boost

quik01ss

iTrader: (24)

i think 9.5:1 should be ok then thank guys ^^

ssdriver27

iTrader: (15)

Im 9.0 to 1 and I wish I went 9.5 to 1. sluggish in low rpms or when not in boost. just go forged with weisco 2618 pistons and a stainless chrome plated rings. 9.0 or 9.5 should work well. ~Guy

Websy21

iTrader: (34)

What he said unless you want to run allot of boost and get the msot out of pump gas. I built my 370 with 8.5 CR and plan to max out my 80gts up to about 18psi on pump with meth if it needs it up top.

Sounds like you want to run mid boost, so 9-9.5 would be cool. Heck stock blocks push up to 10psi before they grenade and some go up to 12 or more with claims of it holding for awhile. Allot of people run 317 castings on there stock blocks for insurance which drops it about half a point to 9.5CR and run 10-12 psi. So with a built motor that should be cake, if you want to turn up the wick get some meth or throw in race gas when you go to the track.

MY99TAWS6

iTrader: (3)

Running more boost dont solve the problem of off boost performance. But thought some guys said they didn't notice loss of performance with 8.5 ?? I would think higher compression would also help give quicker spool up. I went 9.5 to 1 but do plan on running an alc/meth system all the time and maybe e85 later. I am shooting for maybe 12.5 psi or so as likely max daily boost and 10psi is likely going to be more than fine even. I am expecting a monster ! Also bigger motor will let you run lower boost and give you better off boost torque and quicker spool up. But of course it all costs more money. FI is not that cheap!

dman

iTrader: (5)

compression is not your enemy, and you should have a power goal in mind not a spot on the boost gauge. If you can acheive your power goal with 10:1 comp and run less boost your going to enjoy the car on the street alot more than the limp wrist 8:1 motor. Not to mention better fuel economy due to better VE. I've always setup my street turbo motors with 9 - 9.5:1 comp and set a timing curve to match the octane of the fuel used. You'll get less of that "light switch" feeling you get from low comp/high boost when the power comes in. My lastest combo will have 10:1 comp and twin turbos. I have no predetermined boost level, just a performance goal which is all that matters. Not to mention that I will also be running E85 fuel along with my meth injection kit.