| I have been itching to steal a AEM CAI
from inventory for a while now and I finally broke down and installed
one on my car. My test results were surprising, I knew the factory
intake was restrictive but I didn't know just how restrictive it really
was.
The first step was to test the
restriction that the stock intake created. I used a manometer to
measure the pressure drop present after the air box. I tapped the
manometer into the turbo inlet hose and made a few second gear runs to
measure the restriction. The restriction was a staggering 26"
of water which converts to .938 PSI. This is the difference in
pressure between the atmosphere and the turbo inlet hose, so nearly a
full pound of pressure is lost due to the restrictiveness of the factory
intake snorkel, resonator chamber, air filter, and air box.
The next step was to install the AEM
CAI and take some more measurements. Installation was fairly
straightforward, the AEM CAI comes with very thorough instructions
which includes plenty of pictures. The only real challenge during
the installation was not breaking any of
the plastic clips that hold the wheel well molding in place. A
little patience and a gentle hand and I managed to remove all the clips
without breaking any. To gain a little extra room to maneuver I opted to remove the
wheel/tire instead of just turning the wheels all the way to the right like the
instructions recommended. From start to finish the installation
took me about one hour.
The first thing I noticed when
driving the car was how much
more audible the turbo was as it spools up, ah I love that sound.
The blow off valve can also be heard more clearly but it's not TFATF
loud. Right away I also noticed that my boost pressure had jumped
by about 1/2 PSI, a good indicator that a lot of restriction was removed
from the intake. A quick adjustment of the OAMBC restored the boost pressure to the
same level it was before the installation of the AEM CAI, 14.5 PSI in
second gear.
After making a few runs in second
gear the drop in intake restriction was very noticeable. The
restriction caused by the AEM CAI was 12" of water or about 0.433
PSI, less than half the restriction posed by the factory setup!
The seat of the pants difference in horsepower was great, power didn't
taper off as quickly when reaching the higher end of the RPM range and
boost response was quicker. Before the installation of the AEM CAI
revving the car in neutral from idle to redline the turbo could only
produce 3 or 4 PSI of boost pressure, now 8 to 10 PSI of pressure can be
seen. This reduction in spool time helps driveability and also makes
launching the car easier because the boost comes on quicker which
reduces the chance of bogging down the car off the line. |
