High Compression and Blower?

87witeTtop · Jul 20, 2006

Here is the deal. I got my car dyno tuned and i have a nice new supership. Car is runing good i'll find out my ET tomorrow night but all im puttin to the ground is 270 ponies! Not good enough for me. Ive got a 306 with forged TWR pistons (domed of course for that nice high compression, havnt done a compression check yet but i know its up there) E303 Cam, FRPP 1.6 roller rockers, GT40 heads, Trick flow upper and lower inake. Thats the basic engine mods i have. Is it out of the question to blow it? I understand it is possible as long as i run low boost like 6-9psi. Anybody have any idea? Any advice will be greatly appreciated!!

gcwh02 · Jul 20, 2006

We need to know what you consider high compression?

bluevenom867 · Jul 20, 2006

gcwh02 said:
We need to know what you consider high compression?

Yup.

Also,if race gas is a possablity then most likely you can run more than enough boost on your "high compression" (unless its like 14.5:1,witch I doubt).

87witeTtop · Jul 21, 2006

I think its somewhere around 11 and the dude at axcelerated motorsports who dyno tuned my car told me thats a little too to much and i if i run a blower with too much boost i'll detonate. I understand that optimal compression for a blower is around 8

QUIKSVT · Jul 21, 2006

if your 11:1 then no blower

270 out of a 306 is sad if you got 11:1

FastDriver · Jul 21, 2006

Actually, that's not true. You can run a blower and a lot of boost with race gas. I would ask the same question on turbomustangs.com, and in particular I would ask it in the LS1 section. I've seen LS1s running around with blowers and turbos claiming to run stock shortblocks. They come from the factory pushing near 11:1 CR. If they can do it, you probably can too. The thing is, you'd really have retard the timing and keep the boost low to get it to work on pump gas.

But, why go through all the hassle? Just spray it down with nitrous, which isn't affected by compression ratio as much. You can run a 150 shot of nitrous without any problems if you tune for it. If I had your car, this would be my power adder of choice.

Chris

FastDriver · Jul 21, 2006

QUIKSVT said:
if your 11:1 then no blower

270 out of a 306 is sad if you got 11:1

In what did you run a 6.43@238 mph?

88Stang331 · Jul 21, 2006

QUIKSVT said:
if your 11:1 then no blower

270 out of a 306 is sad if you got 11:1

the only thing i have done is heads and intake and i'm putting down 270, with low compression.

JS94cobra · Jul 21, 2006

Is anything done to those GT40 heads? Any port or valve work? If you are putting 270 with stock gt40 heads I would bet you'd get over 300 with some different heads. Of course you'd want to stay with a 64 or 65cc head because any smaller your CR is going to go up even more. As far as the blower is concerned, if it was me I would not run a blower with a 11:1 CR. Although 6lbs boost may be ok with the right tune. With a 11:1 CR and 6 lbs boost your new CR will be around 15.5:1. At 8lbs boost it will be around 17:1. If you want a blower and some more boost get some head with a BIG combustion chamber...70cc 72cc...to try to get that CR down some. Or you could get some flat top or dished pistons. I know the piston part is a pain but you'd be happy with the end result and some 400+rwhp.

QUIKSVT · Jul 21, 2006

WELL I WAS THINKING THAT THE GUY AIGHT GOING TO RUN RACE GAS.. AS MOST OF US JUST RUN PUMP GAS.. BUT YES EVERYTHING IS POSSIBLE.. BUT I WOULDN'T DO IT.. I WOULD OF RAN 9:1 THEN THE BLOWER.. 11:1CR ON RACE GAS AND 6-9 POUNDS STILL AIGHT SMART.. BUT OH WAIT.. I'M SURE YOU GUYS GOT A "FRIEND" OR "READ" ABOUT A GUY DOING IT..

TELL ME THIS THEN.. IF 11:1CR AND A BLOWER WORKS SO WELL.. THEN WHY IN THE WORLD DOES EVERYONE THAT BUILDS A BLOWER MOTOR RUN LOW COMPRESSION?

STANGateURlilSS · Jul 21, 2006

QUIKSVT said:
WELL I WAS THINKING THAT THE GUY AIGHT GOING TO RUN RACE GAS.. AS MOST OF US JUST RUN PUMP GAS.. BUT YES EVERYTHING IS POSSIBLE.. BUT I WOULDN'T DO IT.. I WOULD OF RAN 9:1 THEN THE BLOWER.. 11:1CR ON RACE GAS AND 6-9 POUNDS STILL AIGHT SMART.. BUT OH WAIT.. I'M SURE YOU GUYS GOT A "FRIEND" OR "READ" ABOUT A GUY DOING IT..

TELL ME THIS THEN.. IF 11:1CR AND A BLOWER WORKS SO WELL.. THEN WHY IN THE WORLD DOES EVERYONE THAT BUILDS A BLOWER MOTOR RUN LOW COMPRESSION?

wow what a smart guy.. thats probably why he makes 977whp @8000+ rpm on a stock short block lmao

88Stang331 · Jul 21, 2006

If you are going to go high compression and boost, i would suggest switching to E85

Mendez33 · Jul 21, 2006

STANGateURlilSS said:
wow what a smart guy.. thats probably why he makes 977whp @8000+ rpm

I want to hear more about his 95 Cobra and his 6.43@238 mph.

jrichker · Jul 21, 2006

High compression & boost means you need water/alcohol injection or the order of a Snow unit. See http://www.snowperformance.net/ for more information.

The mid 60's Olds Cutlass had an aluminum block/aluminum head 215 cu in V8 that ran 10.25:1 compression ratio and a small turbo. It used a water/alcohol injection system as standard equipment from the factory to run boost using 100 octane pump gas.

luckythirteen13 · Jul 21, 2006

you can run 11:1 cr with a sc if you have the right cam. by that i mean a cam that would bleed off some of that compression out the exhaust.

and 270hp with 11:1 is piss poor there is something wrong with your car or your tuner is retarded

87witeTtop · Jul 21, 2006

Thanks guys for the advice, i still need to look into this a bit more. As for QuikSVT and luchythirteen13, im sorry that i didnt have you tune my car, i didnt post this thread to ask what you thought my rwhp is nor do i give a crap what you may think. Before you post stupid replies you should check the topic of discussion. Thanks though.

87witeTtop · Jul 21, 2006

Another question, i dont know a lot bout dyno's i just put my car on it...ya know what i mean. How accurate is a dynojet? How often does it need to be calibrated and if its not calibrated, how off could it be? Cause to be honest, i was expecting more horsepower than that.

ninety15.0 · Jul 21, 2006

Those Hp numbers seem a little low...but they arent that bad. It all depends on the supporting mods. I think that 11:1 is high but its not like that compression alone is going to be worth 50 hp. Tuning has a lot to do with it sure...but with an E-303 and unported gt-40's you cant expect crazy numbers. 87whiteTtop, i would take the advice of some of the others...get some big chambered heads to drop the compression a bit and then run low boost...at that point you will be makin serious power! good luck

2002BLGT · Jul 21, 2006

87witeTtop said:
Another question, i dont know a lot bout dyno's i just put my car on it...ya know what i mean. How accurate is a dynojet? How often does it need to be calibrated and if its not calibrated, how off could it be? Cause to be honest, i was expecting more horsepower than that.

your rwhp is right where it should be with those heads im sure of it , but if I were you I would drop the SC idea and get some nitrous , thats what I am going to do with my 306 with 11.5 to one compression , and your compression is probably more like 10.5 to one if anything if the heads are not milled and your engine block was not decked so you might wanna try to check it out to actually see what it is before you make your mind up , if its anywhere close to 10 then a blowers not going to hurt it at all

ninety15.0 · Jul 21, 2006

2002BLGT said:
your rwhp is right where it should be with those heads im sure of it , but if I were you I would drop the SC idea and get some nitrous , thats what I am going to do with my 306 with 11.5 to one compression , and your compression is probably more like 10.5 to one if anything if the heads are not milled and your engine block was not decked so you might wanna try to check it out to actually see what it is before you make your mind up , if its anywhere close to 10 then a blowers not going to hurt it at all

I would also be interested in the Actual CR. I would like to know what kind of pistons are in there to get 11:1 on a stock block/stock gt-40 heads. My CR in my 306 right now is just at 10:1 and im not thinking twice to put a blower on it next spring. Run 6-9 psi and a safe tune with the tweecer...

High Compression and Blower?

New Member

New Member

I will have images of molesting stuffed animals in

New Member

New Member

I was uncomfortably high & wearing a helmet

I was uncomfortably high & wearing a helmet

New Member

Banned

New Member

New Member

New Member

StangNet's favorite TOOL

New Member

New Member

New Member

New Member

Well-Known Member

New Member

Similar threads

Privacy & Transparency

Privacy & Transparency