Looking for some info on NA intake design...I've always been under the impression that long runners on an intake are for higher RPM use -- i.e. tuned for high RPM.

The 2.2 and 2.4 intakes are cumbersum and have a big plenum and super long runners to the cylinder head. The TB sits on top and the air goes down about 8" into the plenum and then each cylinder tube is over 14" long to the cylinder head.

Yesterday I looked at a Civic SI 2.0 engine for the first time and was surprised to see a very short-ram intake. the TB is on the side with a small plenum (maybe 10" long) and the individual intakes run off the plenum pretty straight into the cylinder head -- each is about 8" long. Shouldn't this design be for low end performance and not high RPM performance? It just seems to go against every tech article I've read about intake design considering the Civic SI 2.0 revs so high.

This isn't bashing the Cobalt nor promoting the Civic -- just would like to hear from some knowlegable tech on the intake design differences.

You have it backwords, Long runners is for better low end torque low rpm power, and short runners are for high RPM power..

You have it backwords, Long runners is for better low end torque low rpm power, and short runners are for high RPM power..

this is correct. its the same as exhaust. shorty header = top end, long tubes = bottom end

this is correct. its the same as exhaust. shorty header = top end, long tubes = bottom end

dual intake ftmfw





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what did i just say?:wtf:
i'm turning into cc08

^^ you lost me there too actually...lol