Phil99vette

iTrader: (11)

Think of compression as a multiplier and boost as your base. The higher the multiplier the greater your compression is under high boost levels. The reason guys like to run low compression and high boost is it yeilds a lower effective compresion. Bottom line is the cylinder pressure it makes, you can make the same power with 2 different boost levels and 2 different compression ratios if it makes the same cylinder pressure. I like to run high compression for a couple reasons.... it makes spooling easier and you can make way more power when you throw the juice at it. For example....

8:1 and 30# of boost makes your effective compression 24:1
10.5:1 and 30# makes your effective compression 32:1

So your compression went up 2 points while your effective compression went up 8 points. But beware you better have an engine that can handle it. Our ECR is roughly around 40:1.

ZL1Killa

iTrader: (17)

Holla back. LOL. I can tell you know engines pretty durn well. and very well stated, especially "But beware you better have an engine that can handle it."

Phil99vette

iTrader: (11)

LOL, we cant wait to try and run it out the back door again.... last year it went 199.86 on a pass where we pedaled it right at the 60' mark and put a cylinder out just before 1/8. Should go 210+ very easy.

383lt1impala

iTrader: (33)

That's the idea im gonna run c16 and 6-10psi depending on what my engine builder likes.

JoshuaGrooms83

iTrader: (2)

ok so with a really good tune and a stock 10.1 CR, whats a good safe psi level with a T76 rear mounted turbo? tryign to bring a good thread back alive.

brians91formula

iTrader: (12)

Forged motor or stock? Head studs or head bolts?

JoshuaGrooms83

iTrader: (2)

stock block but looking into arp head bolts or studs, leaning towards studs though. still on the fence with 317 heads.

MaxxMitchell

iTrader: (15)

I have a few guys pushing 22-24lbs with 76mm's up front on 10:1. But all are on E85, LS9 gaskets, studs, stock heads, cams similar to the LS6.

Grr

iTrader: (2)

I am putting together a rearmount setup with the 13:1 motor in my sig, on E85 of course not trying to make big power jsut 650whp or so. Probably only get away with 5-7psi before I start pushing water since the heads are so thin

JoshuaGrooms83

iTrader: (2)

um, gonna stick to premium pump gas since E85 is hard to find lol

tonybain42

I've got a camaro with a 370ci, lq4 block, mahle forged pistons, compstar h-beams, dart 205 heads with ARP headbolts, fast 90/90 running about 11.3:1 CR I'm planning on adding a t70 rear mount turbo and was wondering what a safe boost level would be. The motor made 440 at the tire at EPS. and i'm running a T56 with a 9" rear and 4.11 gears, mainly street driven, but more power could never hurt, lol!

ZL1Killa

iTrader: (17)

Stud it:
SEXY


on stock block....what about pistons and rods? stock also? if you are keeping 10:1 compression and running on 93 octane I see no reason why you couldn't run ~14~16 degrees maximum timing and run 12~14psi (to be in the 2bar sensor range). You will want to keep the fuel mixture in the 11s keeping her safe

JoshuaGrooms83

iTrader: (2)

nice! i am actually. already on my "official" list of things to get lol

heroz22

Ok fellas I know this is an old thread but this is what I want to do. The motor is 11.5:1 CR, I have JE custom nitrous pistons, stock rods with ARP rod botls, ARP main studs, ARP head studs, Thunder racing heads (Same as PRC stage 2.5) Thunder racing nitrous cam specs are close to 232/238, 42lb injectors, 255 pump and right now I am sendign a 150 shot to it and she loves it but I am wanting to go boost. I want to Build my own kit with a PTE 6262 on the rear and I was just curious if I could do this on pump. If not can I go E85 and make it work and work well. My power goal is right around 700. Please let me know what you guys think

THADD

iTrader: (12)

Damn back from the dead. Ok so how about this, a guy I race with is running 12:1 comp with a 76mm around 25 lbs on c16. Yes it's fast

smokeshow

iTrader: (17)

No, not on pump gas. Not with that turbo either. Or that cam. Or injectors or fuel pump. Everything would need to change.

SuperC1

iTrader: (4)

For this I would run a bigger turbo and make it a front mount if possible, and then I wouldn't run any more than 8-12 psi with a good tune. I actually did this with a 76mm on 12psi and pump gas and it ran like a scald ape.

gallo-lo

iTrader: (11)

Lq9 stock spec build using twin s366 BW e85 drinker..

Black Reign

iTrader: (2)

Studed 408 at 9.7:1 with twins at 21 on e85 ftw!

Michaelfir

Im running a 12to1 compression BBC with tunnel ram in the picture i think i will show that on new guy,anyway i have a twin hybrid T3T4 turbos thinking about adding the turbo manifolds and tap into both carbs 1 for each with carb hat. I was told a high compression engine give u that good leave and the small 8lb turbos will spull faster than the large. the turbos have a built in blow offs and i have a couple of waiste gates, 1-5/8" headers shortfacing strait up i was going to wrap them for the heat. i running canfield heads big valves, 697 lft roller cam lifter all roller etc. any thoughts?