Several months ago I purchased and installed the AEM CAI that mounts an intake induction to the underside of the hood to make use of the non-functional hood scoop with plastic grill insert on Turbo models. The plastic grill insert is then removed to allow unrestricted airflow into the AEM induction to the AEM airbox, while still using the stock CAI pipe.

A few months go by and for the most part I'm very happy, but recently I had my entire MCS completely repainted, paint and clearcoat. I went ahead and had the hood scoop replaced do to warping and those two front fog light covers. I instructed the body shop NOT to install the small plastic grill that goes into the hood scoop because that would almost completely restrict my AEM CAI!

So I pick up Mini and what do you know, they installed the plastic grill into the hood scoop blocking most of the AEM induction under the hood. I'm exhausted at this point and put off removing it till my next day off work, but in those few days I notice that my Mini is faster in acceleration and feels snappier like it's got more torque. My GF that drives everywhere with me asks if I added any performance enhancing mods.

If my GF can tell there's a difference along with me then it's NO placebo effect! She knows NOTHING about cars and can barely operate a computer! So last night I took things a little further, I took one my T-shirt and stuffed it into the AEM CAI. To my surprise it's ever faster now that it's completely block off now, what in the world is going here, is it my Mini's inability to adapt to the AEM CAI or is there something else going on here? Do not take what stated and say it's my imagination because it is NOT!

I'm excited and confused by all of this, for I leaving my shirt in the AEM induction because I still believe that the airbox and intake charge pipe are giving positive gains. There's a huge difference between the stock intake charge pipe and the AEM one leading from the airbox to the back of the turbo.

I would appreciate any and all feedback as to why this happening!

Regards,
Systemlord.

 

i have a theory (stand back! this may be dangerous)..

many people report "performance gains" when switching back to the stock airbox from an aftermarket intake.......now the stock intake is pretty free flowing, but its not as free flowing as an open pod filter.

from what i understand about the ECU in our cars is that it will adjust the boost pressure to compensate for its environment to reach a set target power.

now if the air intake is less restricitive, the turbo doesnt have to work as hard to get the air it needs to reach the target power level set by the ECU.....so in a free flowing system, the Turbo may only have to boost a fraction of what it usually does.

i am assuming this is why many people report that their car feels like it has less low end power when switching to a pod filter.



now if you clog up the airflow, the turbo will have to work harder to pull more air to reach that set performance level......

so with a very restrictive system, the car may feel like it has more low end power because the trurbo is working much harder than it has to.

now i havent done any dyno tests to back this up.....but im willing to bet if you ran a pod filter car, then ran a car with a very restrictive intake, that you would see the pod filter cars "power band" will be shifted to higher in the RPM range and the restricide intakes cars "power band" would be lower in the RPM range......

now what about overall HP....well im no rocket scientist, but i can almost gaurantee that your heavily restriced intake is cutting your HP by a hefty amount.

again, this is all theory......but it makes sense to me at 8am with no coffee.

 

Had an old 80's 750 Suzuki that came with individual cone filters on each carb, I know this is not the same but it ran 200% better once the factory air box was put back on.

IMO CAI's have little use on a forced air motor.

 

If you look at the bulk of te aftermarket coices they basically are refinig the airflow in the piping more than the filter. Or they just open the top of the air box while reusiung the already factory CAI. Im curious has anyone done any experimenting with redoing the factory inlet tube to either a smooter less turbulent design or a differernt shorter overall path to the turbo. I know in race applications the intake is just turbo inlet and funnel shrt asnd sweet.