Wassup to all of you...new to this forum.

Anyways, I have a 2000 Civic SiR. That should be the Canadian version of the US Si I think. I hear that it's not a great idea to do force induction to the b16a2 engines cause they have a high compression(10.2:1??) ratio. Is that true?

If it is true, then why is it a bad idea to fi a high compression engine? I was just told that it was a bad idea, but never got an explanation as to why.

 

People say its a bad idea, well they are dumb. it's a GREAT idea and you'll be even faster, however the downside is that you will need VERY good fuel management, and preferably 93+ octane gas. People always say "get low compression pistons and boost up!" ...what they don't realize is when they aren't in boost the car will be slower with a 9:1 compression ratio....i'm in the process of rebuilding my engine right now and i might just stick with 10:1 ratio, i don't want to lose any more power to get more boost, and with new pistons + rods, 12-15 psi with speed pro fuel management, it will be just fine. when you lower the compression ratio, there's more boost to play with.

 

Let me give yo the facts here... boosting a high compression engine tends to cause more heat build up in the cylinders...more heat = higher chances of pre-igniton of air/fuel mixture during the compression cycle or more commonly known as detonation. Detonation can cause severe damage to the engine (ie the rods and pistons)...

Yes, lowering the compression does cause power degradation, but only in an naturally aspired engine...lowering the compression on a boosted engine allows you to add more boost hence more power..


[Modified by MiraiZ, 8:08 PM 9/13/2001]

 

I second that!

 

Actually, I plan to do the same thing on my 95 GSR. Overly simplified, existing compression + boost determines what octane you have to run to prevent detonation. Or, if you're sticking with pump gas, stick with low / moderate boost. 5-7 psi in a well designed system with good fuel and temperature management could be worth as much as a 50% increase in torque / power. That sounds cool to me....

See Corky Bell's book - it's a very easy read and will answer many of your questions.

--
DoctorBob
"They will come out of this thing with their flag high." - Gordon Sinclair