Exhaust pipes over crossmember?

[Hair]

You guys that run your pipes over the top of the first cross member, do you notice any additional heat thru the floorboard. Like sitting in traffic on a hot summer day baking like a biscuit or anything? I hate heat, scared to death of it, anything over 70, I start looking for an A/C LOL!

[grndcont]

I just installed sound detinning and heat barrier from dynamat.

[70STOVEBOLT]

Originally Posted by Hair

You guys that run your pipes over the top of the first cross member, do you notice any additional heat thru the floorboard. Like sitting in traffic on a hot summer day baking like a biscuit or anything? I hate heat, scared to death of it, anything over 70, I start looking for an A/C LOL!

Not sure what cross member you are talking about. Can you elaborate?

[67C10Step]

Gotta be the cross member the drive shaft passes through and the trailing arms connect to. I've seen many cut holes in them and pass through those. Considering that for mine in the future.

grndcont - what steering wheel is that? you can PM me as I don't want to hijack this thread.

[HO455]

I'm guessing it is the transmission crossmember he is referring to. It would be hard to quantify it as someone would have had to run their exhaust both under and above the crossmember to be able to answer the question accurately.

What I can speak to is on my Burban the mufflers were between the transmission crossmember and the trailing arm crossmember. (Basically under the front seat.) They were installed at an angle to clear the drive shaft and the result was the foam insulation under the carpet melted. (It wasn't hot enough to discolor the paint)This only occurred where the mufflers were one inch or less from the floorboard. No problems with the new exhaust system. (I had the carpeting up to install new rear seats last fall. About 15k miles at that point.) Not the best picture but it may show enough. I haven't noticed any unusual heat as a result of how they are installed. In the interest of full disclosure, I did spend my early years growing up in the desert south of Reno in the time before air conditioning.
Scroll to post 114 on the link below to see the melted areas.


https://67-72chevytrucks.com/vboard/...=698377&page=5

[Mike C]

I'm sure he is talking the transmission crossmember. And that is how it is routed on the 4x4 trucks stock since their crossmember hangs lower. I plan on routing it that way on my short step but I still need to swap the motor first!

I already cut openings in the trailing arm crossmember and welded in 4" pipe reinforcements to run exhaust through that. But on my leaf spring truck, LOTS more clearance for exhaust.