AEM CAI intake pipe measurement...

[myeverlovinsir]

I would appreciate it if someone out there with the AEM CAI could take the measurement of the pipe diameter at the TB where it mates with the rubber hosing. I would do it, but it's bloody cold out and if someone is bored, please do this check. Hondata needs some accurate measurements to try to troubleshoot their tune. I was under the impression that it was 2.75" (69.85mm) but am not entirely sure. Thanks again to the first one who does this. Wish I lived in a warmer environment. ;)

[myeverlovinsir]

Well, it seems that lewjay is the winner on this one. He came thru with the numbers. The AEM CAI is 2.5" in diameter which translates to 63.5mm at the TB mouth. Thanks to lewjay for the info.;)

[lewjay]

Here's a blurry ass pic
http://www.dslextreme.com/users/lewjay//ep/aemcai.jpg

[IceD out N CALI]

blurry but not bad;)

[Suk02Si]

hmm, I wonder if the Injen is the same diameter.:o

[lewjay]

I believe injen is 3in. Oh yeah, that's speedracers' CAI...I just got it.;)

[myeverlovinsir]

Hmmm... looking at the pic. the ID on that is closer to 2-3/8" and the outside is 2.5", so I would say our available flow diameter is 60.325mm. This changes things a bit. The concern raised by hondata was how could the CAI provide any benifit to the 64mm TB if the restriction is 60mm at the mouth of the CAI? Baffling indeed. Some how the gains are still there and this is just another weird puzzle about how these engines react to a larger TB. If the Injen is larger I will try a swap to see if there is any benifit. Can someone with an Injen CAI please do the same check and provide a pic as well. tks.;)

[chunky]

Originally posted by myeverlovinsir
Hmmm... looking at the pic. the ID on that is closer to 2-3/8" and the outside is 2.5", so I would say our available flow diameter is 60.325mm. This changes things a bit. The concern raised by hondata was how could the CAI provide any benifit to the 64mm TB if the restriction is 60mm at the mouth of the CAI? Baffling indeed. Some how the gains are still there and this is just another weird puzzle about how these engines react to a larger TB. If the Injen is larger I will try a swap to see if there is any benifit. Can someone with an Injen CAI please do the same check and provide a pic as well. tks.;)

colder air would account for almost all of the gains i'm sure.

also, reducing the volume of air in the intake tract decreases pumping losses.

And then of course there are the resonance benefits.

[myeverlovinsir]

Originally posted by chunky


colder air would account for almost all of the gains i'm sure.

also, reducing the volume of air in the intake tract decreases pumping losses.

And then of course there are the resonance benefits.

I agree, decreased pumping losses and higher intake velocity. I wonder if a matched intake pipe diameter would help or hinder the results? Hondata is just as perplexed why this resonance is more pronounced with the smaller intake diameter and larger bore (64mm) TB. Hondata also mentioned that they did not see the any gains with the same AEM CAI and bored out TB on the type-s.

BTW: chunky, do you happen to know the diameter of the Injen CAI piping?

[chunky]

Originally posted by myeverlovinsir


I agree, decreased pumping losses and higher intake velocity. I wonder if a matched intake pipe diameter would help or hinder the results? Hondata is just as perplexed why this resonance is more pronounced with the smaller intake diameter and larger bore (64mm) TB. Hondata also mentioned that they did not see the any gains with the same AEM CAI and bored out TB on the type-s.

BTW: chunky, do you happen to know the diameter of the Injen CAI piping?

My guess would be that a matched intake pipe diameter would result in slightly more top end power with little to no change in midrange.

I don't know the diameter on the injen piping. I'm going with a custom intake design - the specs of which will be released at a later time :-D. But My general philosophy on intakes is to have an intake pipe that is at least 1/4" larger in diameter than the TB but no more than 1/2" larger than the TB diameter. This creates a velocity stack effect as the air passes through the TB.

As to why AEM went with such narrow piping for our cars, it may have been done out of necessity due to the space limitations near the TB. Otherwise I cannot think of any reason why the AEM intake would go with a pipe diameter that is smaller than the TB opening.