Maybe someone more intelligent or who knows more about Minis can explain this to me. A few months I got a used, lightly modded 04 MCS and I the other day I was examining the Dinan Intake a little more closely. It seems to draw outside air from the power steering compartment by way of the vent by the windshield. This is where I get confused. When driving at speed, wouldnt the rushing air outside the vent create negative pressure relative to the calm(er) air inside the compartment from which the intake is open to? It seems this would actaully be drawing air from within the car and expelling it out the vent. Accordingly wouldnt the engine have to work harder against this vaccum to draw air in, as opposed to having a slight "ram air" effect or simply a neutral pressure environment? Even the black plastic grating appears designed to expell air rather than allow it to enter the conpartment.

Surely im wrong about this, but I just want someone who knows their Minis to splain it to me!!

Thanks!!!!!!!

 

All CAI's draw air from the exact same place.Even stock.

 

Tests done a couple of years ago showed that there was almost zero pressure at the base of the windshield on our cars. Consequently the engine "sucks" air in through the filter quite easily, against atmospheric pressure at best.
The problem with minis is not insufficient air unless you are trying to produce over 250HP. The temperature of that air, on the other hand, is a serious concern...

 

Of course the vent air comes through the cowl vents, so if there's air rushing through all that duct work, there must be some pressure...

 

Thanks Dr Phil, Im slowly discovering that a surprisingly large number of Mini owners actually take the time to actually test all the little things that car owners often speculate about. Its a cool phenomenon!

I must agree with you about temperature. Our weather here in Texas has recently snapped from 90's+ to the low 70's, even down to the 40's a few nights and I feel like some one turned my 15% pulley into a 19% without my knowledge. Aside from not having to run the ac 24/7, the cold air has completely changed the feel of the power band and Im now DREADING next summer's heat!!! I know there is nothing you can do to eliminate the effects of 100 deg temps, but to what extent do sprayers, diverters, scoops counteract the heat's power drain? Will I have to replace ICs to really see a difference?

 

That is actually aerodynamically true for almost all street cars. Even the 60's era cars - hence the development of cowl induction hoods.

 

Honestly, changing your IC would not yield significant improvements, especially compared to some of the alternatives--specifically water/meth injection or variations on that theme. I believe a meth system is just around the corner that may be competitive in price with some of the more expensive after-market ICs. Since they offer substantially better IAT drops, I would advise waiting. Especially as it might be a long winter...