Hot exhaust pipes under passenger and drivers seat?

[FWP]

Anyone have this problem with a TBI swap? It only happens when under high power for 30 minutes or more- i.e. highway driving with 42's and a 7000 lb pig

Engine temp is normal, the tranny gets a little warm as I would expect. Stock puter, mild cam. It's been this way ever since the swap, starting with 37's, 38.5's then 42's. Stock manifolds, if that makes a difference.

Ideas? Thoughts?

 

[sweetk30]

what cam and do you have the specs? you might need a custom chip if its off from stock a bit to far.

 

[4X4HIGH]

An engine running too rich or too lean can make the exhaust pretty hot.

 

[Hossbaby50]

With my dual exhaust & TPI I get hotspots under the seats and under the footwell for the rear passenger area. I still have carpet even for now. When I loose the carpet I imagine the problem will just get worse.

I am going to get a good 3" exhaust system built for the truck though which I am hoping will help the problem some and keep the exhaust a little further away from the floorpan.

Harley

 

[pauly383]

Harley , I got it too , but I assume in our case its the cats getting the hot . You have two , I have one . My hottest spot is just above the cat which sticks about 4 inches rearward of the heat shield .

 

[1979jimmy350]

i would guess the cat is the reason also, if you have a stock chip and a mild cam you are going to let a lot of unburned gas into the exaust causing the cat to get really hot, there are a few ways to solve this, one you should really get a chip to make the truck run the best it can, you could also cut the cat out but then your truck is still not running the best. I would suggest getting a chip and go from there