Heat under dash

[Granville]

The AC does fine for the waste up, but there is a lot of hot air coming footwells and under the dash. Has anyone figured a way to remove the hot air out of the footwell areas. Possibly a suction fan and hose which sends the hot air out the wheel well. Any help would be appreciated.

 

[JP Verweij]

Deep vent nostril

 

[Dan Carter]

Sorry for the obvious question, but what heat blanket protection did you use in the footwell? Have you built any kind of heat diversion shield after the radiator to push hot air out the hood slot? Cam T has a good discussion on this. I think Aaron does as well.

I coated my footbox with lizard skin. Heat shroud is on the to do list.

 

[Granville]

Sorry for the obvious question, but what heat blanket protection did you use in the footwell? Have you built any kind of heat diversion shield after the radiator to push hot air out the hood slot? Cam T has a good discussion on this. I think Aaron does as well.

I coated my footbox with lizard skin. Heat shroud is on the to do list.

That is a great question and a heat deflector is going to be my first course of action. I have ordered some heat shielding and tape to line the box. I also ordered several PC cooling fans to install under the dash to move the air. When the outside air ambient temp is 109, heat is an issue.

 

[Will Campbell]

If you have hot air in the footwells, it's because you have leaks between the body and the chassis. Adding a air diversion shield like the one the factory sells will help reduce radiant heat, as will covering the front of the chassis with heat-rejecting coatings. But hot air means you have leaks. Fix them, and your problem will go away.

 

[Howard Jones]

Between the center section body work and the chassis footbox there is a gap aprox. 1/4-1/2 inch wide all the way across the front of the fiberglass "lip" that extends over the edge of the bodywork. This will vent radiator exhaust air directly into the area under the dash and therefor into the footwell area. The air can be a hot as 175F at that point. I found this problem the first time I drove the car. I quickly covered it with duct tap and the heat when away. Thereafter I sealed the gap with thick two sided adhesive tape and then vent the radiator exhaust with a formed duct.

In a street car I would cover the forward bulkhead of the footbox with a good heat mat along with the above ducting and sealing the leading edge of the bodywork. My racecar does not have any insulation on the footbox but the surface does not get hotter than ambient air temp never the less. Sealing and ducting is a 100% fix.

There's pics of my duct on my build thread #960

 

[Granville]

That is great information. I will take the nose off and check that area. Thank you Will and Howard.

Oh ya, i have had the car for a little over a year and just passed 4k miles on the odometer. Yaaaa

 

[Granville]

I just took my Nose off. All the insulation from infront of the driver footbox had fallen out. There was an open gap. I put new insulation and speed tape. Thanks guys the the advise.