I'm looking at internals for an eventual FI build and haven't quite decided on whether I'd like to go with a turbo or a centri application. My question is what an ideal CR is for a turbocharger? Also, what piston brands have a decent reputation?
Compression ratio for turbocharged induction
- Thread starter MR.ADAMS
- Start date
No less than 9.5 to 1. Low compression results in slower turbo spooiling and low pre-boost power...seriously.
You'll probably get a lot of different answers to this question.
I had my short-block built to 9.3:1 after discussing my plans with several shops. I personally wouldn't want it much if any lower than that or out of boost power is going to suffer...
I had my short-block built to 9.3:1 after discussing my plans with several shops. I personally wouldn't want it much if any lower than that or out of boost power is going to suffer...
I'm in the process of a new turbo build and I am shooting for around 9.5 or so but I am running E85.
i have mine around 9.5:1 might be a touch under... and hope it works well with my turbo setup..
Thanks guys, I realized that the CR doesn't differ much between turbo and centri applications, it's the PD blowers that need lower CR.
I've got 8.5 in mine, nothin a 2-step can't overcome:banana:
im at 8.5 now, next build will be with flat tops better low end spool and torque
9.5.1.
I would go no lower than 9.5 to 1...ever. 8.5 to 1 comp results in an hp level that is 5rrwhp lower than the stock conpression at the same boost level, even with a PD blower. I know people running 10 t0 1 compression with turbos and centri superchargers and they are very happy. The pre boost power is great and the turbo engines spool quickly.
Combining a short runner (5-6") and 8.5 to 1 compression results in poor driveability and low power up to 6k when compared to longer runners and higher compression.
Combining a short runner (5-6") and 8.5 to 1 compression results in poor driveability and low power up to 6k when compared to longer runners and higher compression.
Food for thought.
[ame=http://www.modularfords.com/forums/showthread.php?t=154750]Track Results - E85 and 11-1 Compression - ModularFords.com[/ame]
[ame=http://www.modularfords.com/forums/showthread.php?t=154750]Track Results - E85 and 11-1 Compression - ModularFords.com[/ame]
e85 is a great fuel, but it's not readily available everywhere and by the looks of it, it's availablility hasn't expanded in recent months. That thread does however show the potential of a higher compression/low boost setup.
I have a guy running a TT, 324 with 10 to 1 compression and it's on 93 octane, it's pretty impressive.
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Sounds like it! I have an NA 281 with stock compression, and it's on 93 octane lol... shit
So it sounds like the better way would be to go higher compression and lower boost/timing rather than lower compression and more boost/timing, which is what I thought.
I recently sold a set of 75lb injectors I had for my setup with plans to go larger for E85 (I even heard there's a set of high impedence 120's available now). Corn gas is pretty readily available in the area of central Illinois where I live but I'm looking to drive this car a lot... take it to Mustang week, want to go out to California with it, etc. I'm beginning to wonder if it wasn't a mistake to pursue the E85 option...
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