Wrap the downpipe or not?

jdhogg1

87 GN hardtop
Joined
Aug 17, 2007
I just put in a turbo system on my IROC. The 3" downpipe is coated, but things are pretty tight in there. I wrapped it the other night and went cruising, kept the underhood temps down over just the Jet Hot.

Will this eat the Jet Hot and the metal? Or will the Jet Hot protect the pipe? The pipes are mild steel, I believe aluminized.
 
Yes it will eventually kill the metal. Unfortunately the wrap works well and will make the material brittle by not allowing the metal to dissipate the heat. How long ? Who knows. I use it on Street-strip cars , but never on daily drivers.
 
If its a street car if it gets moist it can end up rotting you pipe, Lou is also right about it making the metal brittle
 
Not to hijack the thread, but a friend of mine was suggesting I wrap my downpipe as well, at least the part where it comes close to the inner fenderwell. My DP is T304 stainless--can it be harmed by being wrapped? My car does see a lot of street use; in fact in the year I've had it I've never had it to the track yet. Lots of things to sort out and fix on it first...

Thanks
 
I agree with the above posts. I only wrapped about 6 inches of my D/P where it gets close to the A/C line and also the line, I noticed a big improvement in A/C performance. Wrapped a set of headers in a Dodge a long time ago and had really bad experiences. They absorb fluids like a sponge. Oil leaks turn headers into candles when they get hot, water makes them rust out the next day......
 
I'd rather wrap the pipe and protect other parts from melting and give up a little durability of the pipe.

I had a big problem melting spark plug boots on the passenger side of my stage 2 engine (stage 2 heads and ATR headers). I have MSD high temp sleeve on the wires, but the boots were exposed. I wrapped the downpipe in that area and put DEI sleeves on the spark plug boots. Seems to have solved the issues so far.

My DP is 304SS. I don't think it will have a huge effect on long term durability. The mild steel might be another story.
 
I once saw a set of ATR stainless headers that were wrapped. They were used for street duty. The headers were almost urepairable as the had extensive cracks all over.

On a race car wrapping is usually fine. On a street car I would use it sparingly.
 
Does anyone know just how hot a downpipe gets? Heat is enery, and it takes alot of enerygy to spin that turbine wheel. So a downpipe will not see heat like a set of headers will. Also the down pipe is much less likely to pick up oil compaired to a wrapped crossover pipe. Not sure if it make a difference but that's my 2 cents,
 
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