grampa_stang

We all know our cars are much slower when it's hot out. Is it mainly because of...

1. engine temp alone
2. temp of air coming through the CAI
3. or both

I noticed the Ford Racing CAI heat shieldis sealed againt the hood to prevent the CAI from sucking in air from around the motor
which is real hot. Is this a better design that the JLT/C&L/Steeda etc? If so, has anyone sealed off the aftermarket CAI?
Is it worth it? or am I way off and it won't matter?

Thoughts?

Dantheman

It's probably both. I've heard of people going back to stock with the airbox for the hottest part of the year. I personally don't think it's worth the trouble for that. I guess it's just something that us CAI guys have to deal with. Believe me, I know all about the heat here in Fl.

Mustangmaster

I think it's the temperature of the air plus the high humid moisture in the summer air.

Lifter583

Hot air has less oxygen molecule concentrationper cubic foot of air. Simple physics, less O2, less ability to burn the fuel efficiently and completely. Less power!

grampa_stang

So if we can just get the intake to suck air from outside vs the engine compartment, our cars
will run better. Our engine compartments get very very hot and that air has got to suck for burning.

So the less air pulled from the engine compartment, the better...right? If that's the case, why aren't
our heat shields sealed againt the hood, 90 degree air has to be alot better than 250 degree air.

howarmat

They are sealed against the hood

when you close the hood most shields are touching the underside of the hood. put some chalk on the top of the sheild close the hood and see what happens when you shut the lid.

Lifter583

Actually the 90 degree air will be much less efficient for combustion then say 70 degrees, when we are moving the air is forced in through the grill, and that is why most cai have heat shields with an attempt to seal to the hood. The other main varible is altitude, higher up, less barimetic pressure, less O2 concentration. So if it is hot at higher altitude, NOT GOOD. It all comes down to how much O2 is in a given cubic foot of air and the how many cubic feet of air your engine intakes.