At what point do you think that forced induction is not an option compression wise on a street driven car that can't have C116 fuel in the tank at all times?

If I had a cyclinder compression ratio of 11.87 to 1, any way a turbo or super charger can be ran with low boost levels, say 4-5 psi? At what compression level do you think it would become unsafe??
This would be on an LT1 application, which I think had 10.5 to 1 compression stock, but with the heads, crank, and pistons I have a chance to get would be 11.87.

And how well does alky injection work on these applications, on my GN its a proven octane booster with 24-25# of boost, but those are 8.5 or 8 to 1 compression ratios.

 

Buy a set of relief pistons...save yourself the worries. Alky drops the intake charge temp without intercooling, also helps with the octane, but 12:1 is rough enough to handle without pre-det on the street when the car is naturally-aspirated, nevermind with a power-adder. Doesn't make a whole lot of sense to go through the hassle of adding a supercharger/turbocharger when the whole time you have worry about if by the time you make it to work if you'll have a hole in one of your pistons.

 

It could be done, especially with a big cam to bleed off some cylinder pressure. However, the gains might not be worth it.

Rich

 

Figured that would be the answer, I have an opportunity to get some heads/crank/pintons at a good price just it was off a N/A setup and would bring it to 11.87, and I was planning forced induction. The heads alone are LE3 fully ported and polished, and would raise the LT1 compression from 10.5 to 10.8 and I'm sure 10.8 would be possible to boost to maybe only less than 5 psi but probably not much more on pump gas. I think the stock LT1 can only be boosted to 5 psi with no other mods, an Ls1 is less compression, 10 to 1 and can go to 7 psi stock from what I have read.

Does that sound right? I think I may just stick to stock LT1 ported/polished heads and port match the intake then add the forced Induction.