Thread: Forced Induction Compression Ratios
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Old 01-09-2020, 05:39 PM   #30 (permalink)
Irishrogue
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Quote:
Originally Posted by Gray Goose View Post
What are you guys thoughts on compression ratios when going Forced Induction.

I know most people just keep the stock compression ratio even when rebuilding.

I'm thinking of going 9:1 or 10:1 since I don't have E85 local and I will be running 93 for 95% of my driving. I cannot see it making more than a 10-20 HP difference when using E85 and perhaps no HP loss when using 93 octane, since the timing can be pushed.

I do plan on pushing high boost at some point! I am building this motor to handle big boost and big HP! So the common thought as with most platforms would be to drop the compression ratio.

Thoughts? There is a wealth of knowledge out here and guys who have tried it all.


Thanks
For what it's worth, I went with 9:1 compression on my rebuild and did 685hp 615 tq on 91 octane at 20 lbs of boost. I don't have the low end problem spooler was talking about, I think that's mostly credit to Seb's tuning abilities with the throttle response. From what Seb explained to me the main limiting factor to running higher boost is the intake manifold.
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