Okay I have been reading the se-r mailing list for a while now. They have dyno tests and techtom md-100's to prove that the CAI increases torque and hp over a JWT intake. Since a techtom won't work on 2nd/3rd gen cars, but the So cal 4th gen maxima guys did the same test. The results were that the JWT/SI intake had a higher airflow than the CAI. Now I was thinking we know that with a 3" exhaust you lose lowend-midrange torque because of slower exhaust velocity. Now could the samething be true for the CAI? Its obvious that our engine's will only take in 290 CFM at 6000rpm if our VE (volume metric effeicency) was 95%. If we were say to use a 2.5" tubing this would increase the velocity and improve lowend-midrange torque since the MAF will read a higher flow of air. Before my engine died I was going to try this on the dyno. My CAI from the MAF to the cone filter is 3", but after the MAF the stock tubing is 60mm (2.5"). Is anyone willing to try a custom 3 and 2.5" CAI on the dyno? Actually we don't have to dyno just take the Voltage reading from the MAF at the same points. Like at idle, 4000rpm (torque peak), 5800rpm (power peak) and do an acceleration run through 1st and 2nd gear with both intakes to see which one has a higher MAF voltage.

 

I have a friend who's a mechanical engineer. He used to design CAI systems for Hondas. He would agree with your suspicion that reducing the intake diameter from 3" to 2-1/2" could have a significant effect on low- to medium-range torque.

I don't have a CAI. Otherwise I'd check out what you're suggesting. I hope someone else decides to take you up on it.

 

thats a good thought....for me to try that would be perfect now especially since the CAI is my only power mod...i may be willing to try this over the summer....it all makes perfect sense too....

me and my buddy recently custom made a CAI for his corrolla using mandrel bent aluminized steel..it just so happens we used 2.5" tubing and i noticed in the test drives that there really wasn't a sacrifice in low end power....

now that i think about it...i really got to try this...

 

The only possible drawback here is that while 2.5" seems to be ideal for the 2.0L SR20DE, the VQ30DE ingests much more air in stock form and hence 3" CAI tubing may be much closer to ideal.

Some of the SoCal guys actually used only the PR lower intake arm, and kept the stock resonator piece between the MAF and TB. Supposedly that cut down on noise *slightly* and prevented the flat spot in midrange torque.

 

If anyone wants to do this, I will buy the upper CAI peace to customize my JWT intake. Just email me.

 

Thats true but assuming a NA VQ30DE with a VE (volume metric effiecency) of 100% flows 350CFM at 7000rpm. Since the 4th gen VQ30DE makes its power peak around 5600-5800rpm that is where its VE is most effiecent. Now it is a fact that the 3" PR CAI has less MAF voltage than the SI/JWT intake. A 2.5" CAI should increase the air velocity and MAF voltage. I'd be willing to try it on my max but its not going anywhere for a while .