Compression ratio for Supercharged LS1?

[JeremyRay]

Any body know the ideal compression ratio for an 02 LS1 that will be supercharged at 8-10psi? Still doing my home work. Anybody ever deal with MTI or HPE out of Houston Texas?

[Packy]

I would say around 9.0 to 9.5:1 for the compression ratio. I have dealt with MTI before!

[JeremyRay]

I take it that they did not live up to there advertisement? What went wrong and where would be a good place to go for an engine built to my specs? Thanks for your help.

[Liquifire]

I would agree with the 9.0-9.5 compression.......It should be safe with those levels at that compression.

[JeremyRay]

Thanks for the reply, any other advice you care to give for a supercharged ls1?

[70RScamaro]

Hi, im new here but iam very knowlegeable. I have a engines book and it has a chart in it. it goes by COMP ratio to PSI of boost. so if a stock LS1 has 9.0 or 9.5 with 8 PSi of boost you will have a 13.9:1 Compression ratio with 9.5 u would have a 14.7 comp ratio. its a pattern more boost higher compression ratio's but you would be safe with 9.0 but i think thats the limit you. with this compression ratio you will have to run at least 100 octane. this is why lower intial compression ratio is better for turbos and superchargers

[Liquifire]

then how would you run a vehicle at fourteen to sixteen pounds of boost? According to your formula, you would need rocket fuel to be able to do that. There are people here that run a 8.5 CR and go double digit on the boost and use nitrous. How is this possible with the formula of your book? Lots of people run six or seven pounds of boost on the stock CR, on pump gas. What does your formula say about that?

[C&Cbird]

Most seem to run in the area of 9.0-9.5. I would think trying for 9.0 would be a little safer and maybe even give you the chance to expand a couple of lbs in the future if you wanted to.

[Ed Blown Vert]

The stock 10:1 could handle 8#.

But 9.0-9.5:1 would be better.

I am running 9:1, but I plan on running 10-15# of boost.

[chriSS396]

this is a dumb question but could i ever look at running pump gas with a s/c at 9-12 or really 9-15 lbs of boost

[Liquifire]

this is a dumb question but could i ever look at running pump gas with a s/c at 9-12 or really 9-15 lbs of boost

not on a stock motor if you expect longevity.....but if lower CR is used, then yes.

[Ed Blown Vert]

not on a stock motor if you expect longevity.....but if lower CR is used, then yes.

I run pump gas. But my engine is forged with a CR of 9:1

A stock engine should be able to handle pump gas with 8# of boost.

[djvaly]

hey Ed my 402 ls2 is 11:1 just like LS7 motor, I guess they'd have to forge it to bring the CR to 9s then put a s/c? just curious, perhaps a project in 2 years from now.

[Ed Blown Vert]

hey Ed my 402 ls2 is 11:1 just like LS7 motor, I guess they'd have to forge it to bring the CR to 9s then put a s/c? just curious, perhaps a project in 2 years from now.

You could install a blower now. But you would only be able to run 2-3# of boost.

[djvaly]

You could install a blower now. But you would only be able to run 2-3# of boost.

I see. thanks for the info

[Ed Blown Vert]

I see. thanks for the info

I was able to run 5# on my old engine with 11:1

[djvaly]

and that gave you what rwhp gain at 5#?

[Ed Blown Vert]

I think it was 100 rwhp

[djvaly]

it's definetely worth it. the procharger goes for 4-5k?

[djvaly]

I gotto ask Santa Claus to be nice for next year, this year putting money in the sock for a house perhaps by April next year...