Stefndogg

I was wondering how the compression ratio on a turbo 944 is so much lower than that of a NA 944...I have been thinking about it for a while and the only thing that I could come up with is that the turbo car purposely has a low compression ratio so that you wont blow the manifold with too much boostm, or that they(porsche) take the compression ratio without the turbo on the boil. Is this right?

SidViscous

Yes it is because of the boost. with NA compression and a turbo blowing air you will get detonation, unless you use ridiculous octane.

The Callaway kit didn't just bolt on a turbo, it also replaced the pistons with dished ones so that you would not get these problems.

Legoland951

I like the part "rediculous octane" as long as it comes with rediculous power.

Scootin159

But doesn't the turbo still only require 87 octane? If so, why not raise it to like 9:1 or maybe 9.5:1 and require 89, 91 or even 93 octane gas?

Legoland951

Turbos are supposed to use 91 octane gas right? That's with 8.0 compression.

Scootin159

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Legoland951:
<strong>Turbos are supposed to use 91 octane gas right? That's with 8.0 compression.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">I thought it was 8.5:1