boost with 10.5:1 compression?

[Alxsmt]

from JE

"The piston can take boost as long as you don't detonate"

so it looks like im gonna try a few lbs. does any1 have a good place to start learning about superchargers/setups? i have googled a little bit but havnt even had a chance to sit down and spend a few hours doing it

[SappySE107]

what are you basing that on? A 60V6 that has tried it? if not, don't tell me you can't run 6psi on 10.5:1 with pump gas. I bet 12.4:1 won't run on pump gas either by the logic being used for the above statement, yet it does and is. 11.5:1 on midgrade NA.

Is the LS motor better? Overall probably, but they don't have the I/E flow ratio that the 3500 heads have. They don't have splayed valves. I don't know what their quench is either but you might want to compare specs that matter to knock resistance.

[BillS]

10psi with meth injection and some good gas should be do-able.

Well yeah. The answer to how much boost you can run with 92 octane and 10.5 compression is basically NONE!

If you have access to racing gas then you can run a little boost.

Far better to drop the compression down under about 9.5 and run a reasonable amount of boost.

I run 12-13 psi on 8.5 and on 94 octane it will detonate on a long run (good thing I also run a knock sensor that kills the fuel feed!)

[IsaacHayes]

10psi with meth injection and some good gas should be do-able.

[BillS]

with 10.5 CR, 5-6 psi would be pushing it. the LS1/6 kits are only 4.5 psi. and those engine are better.

I'd agree with that.

You are going to have some righteous detonation problems anywhere above very modest boost.

OTOH, if you do want to try out 10 PSI, be sure to let one of us know so we can be there with a camera....

[torq455]

with 10.5 CR, 5-6 psi would be pushing it. the LS1/6 kits are only 4.5 psi. and those engine are better.

[IsaacHayes]

As long as its not thinner than a stock piston, you should be fine. Stockers work for decent levels of boost..

[SappySE107]

You are good, just do it

[Alxsmt]

well im pretty sure im not gonna do it...

directly from JE.

"The pistons we made you are a 2618 Alloy, and that is our choice material. The difference between a N/A piston and a forced induction is the thicknesses and skirt design."



im pretty sure i could get away with it and be just fine with a small amount of boost but idk if im willing to take that chance. they wernt really specific so i asked them if they didnt recomend it. waiting for a reply... nitrous is my next question for em

[IsaacHayes]

A CSC can approach the efficiency of a turbo, so I think you'll be good with one of these.

[no_doz]

increasing boost on a supercharger isnt quite as simple & nice as increasing it with a turbo-of course you can always lower the pulley size, but then again the supercharger can only spin so fast before its past its peak efficiency & you may start running into problems & may be better off with a bigger blower

[IsaacHayes]

Oh yeah headers will still out flow manifolds even if they are not scavenging.

[95SleeperAcheiva]

you could always run nitro methane fuel, 100% mix! You'll have tons of power for a few passes......Till your pistons slag anyway.

[Alxsmt]

i just dont want a turbo on this engine. a supercharger would be better for what i do anyways

so do i advance the supercharger a few teeth for more boost? or just turn the dial?



thanks guys

[RedBird]

yes but even poorly designed shorty style headers show good gains over stock manifolds. blasting exhaust pulses down a nice, smooth tube with decent transitions is much better than slamming them into the side of a manifold, going 90*, then tumbling haphazardly down a rough, SMALL flow path :P

headers would definately not be negated with a turbo. if they scavenge good without a turbo they'll work decent enough with a rear mounted turbo, too.