nehemiahj

First off yes I have read a lot of other threads and searched them. With that out of the way here we go. Ok so I am going with the Borla exhaust on my 2011 scion xb. I was wanting to add a intake system too. I have narrowed my choices down to 3. I really like Injen but every site I have looked at says its not compatible with a A/T....M/T only. So with that in mind which is better AEM CAI or the K&N SRI? i know that K&N boosts up to 9 hp and AEM is upwards to 5 to 10 or more.

Rockztar

iTrader: (1)

depends of what you want CAI for top end and SRI for low end

if you drive city most of the time id go with k&n sri, if you do a lot of highway driving then CAI, but you also have to think about rain season with a CAI...if you get lots of rain and water puddles where you live then just get the sri

ScionFred

iTrader: (1)

CAI is for more power from low to high end and SRI is for more intake noise and appearance. The engine is a vacuum pump and can only suck in so much air at any given rpm. If that air is colder it contains more oxygen and the ECU will add more fuel providing an increase in both hp and tq. Colder intake air can also handle more ign timing advance without detonation, which also provides more hp and tq.

If you do a lot of city driving a CAI is much better since the SRI will be sucking in very hot air from under the hood. At highway speeds the SRI may perform equally to the CAI in cold weather when underhood temps aren't nearly as high. At slow speeds and on hot summer days, the oem airbox is probably better than a SRI in terms of actual hp and tq.

If you expect to drive through deep standing water, you should equip any CAI with a bypass filter to prevent the slight possibility of hydrolock. IMO K&N's +9whp claim is BS.

FYI here are links to truly independent 2AZ-FE intake system testing:

https://www.scionlife.com/forums/viewtopic.php?t=92108

http://www.importtuner.com/powerpage...rs5/index.html

Given your 3 alternatives, I would definitely get the AEM. As a bonus, the AEM includes the best filter.

nehemiahj

Thanks a lot Fred. I see what your talking about. The AEM CAI is awesome. I know there is a thread on here about bypass filter but I cant find it. How would I do a bypass filter?
Once again I greatly appreciate your help. Looks like you saved me from a 230 mistake from buying that K&N filter!

ScionFred

iTrader: (1)

You're welcome. The bypass valve replaces the silicone coupler that joins the 2 CAI pipes together. In the event that you submerge the filter in water, the valve opens and reduces the vacuum at the filter end so it won't suck in water. You can get the valve from AEM or several others. You just need to get the correct size for your CAI pipes (3" ?).

After looking at the K&N short ram, it's not too bad since it includes a heat shielding box around the filter but I still feel that a true CAI is better. You can tell a lot just by placing your hand in the filter locations with the engine hot and running.