To Wrap or not to Wrap
 

I'm a newbie(dummass) and I'm putting my remanufactured engine back together.
I bought Exhaust wrap. the kind they use for headers and I wrapped the exhaust section of the turbos and installed the heat shield over it. I'm thinking this will lower the under hood temps considerably. Do you think this is a good approach or do you think it will cause the turbos to fail prematurely from excess heat?
Has anyone tried this? It's not too late for me to remove it if the consensus is it's a bad idea.

I'm guessing it won't help much, but it certainly won't hurt. The turbos should already be armored in heat shields, so most of the heat there will be pulled through in the exhaust flow, and the rest is conducted through the engine block, turbo coolant passages and oil passages. None of that should be slowed by the exhaust wrap.

You definitely want the sheilds there because things like splashing rainwater would make short work of a hot manifold.

Dave

I am still breaking in my engine but had it without a wrap and added one about 2-3 weeks ago.

Really no noticable difference in engine heat or cabin heat that I can tell. Though I suspect that a temp gun would notice a couple degrees difference. It does "somewhat" deaden the sound of the downpipe though (less "tingy"). I say if you have it and the engine is out....go ahead and wrap it. Can't hurt. There are some thread that if your DP is mild steel that there is a potential for rust with the wrap on. Otherwise, go for it. And about the chances of turbo failure, I highly doubt it. Just think how much heat the stock DP with precat was generating. A wrap is certainly not as bad as that don't you think?

Good point, although I don't have a down pipe yet. I may leave the precat on until it makes it thru inspection and I actually have tags on the car.

might want to search on "wrap" or "header wrap". there are so many threads about this already with lots of good info.

You can still pass emissions with just a main cat. The pre-cat is just for warm up.

Edit. I see that you were talking about inspection, not just emissions, so maybe you will want the pre-cat for the visual...Sorry.

Although I've never heard of anyone failing for having a downpipe installed. You can simply tell them "hey, some exhaust shop installed that for me, what do you mean it can't pass?". And that's assuming the inspector even knows what a stock downpipe looks like. Really, everyone knows that a single cat is the important thing anyway.

Dave

Dave,
Good friend of mine made a small blanket out of the wrap material and just laid it over the heat shield (between the turbo's and the Y-pipe) you wouldn't believe the difference. If he's wrapped it under the shields it should work just as well if not better. Jack

That's really interesting - it would make sense since there is usually a column of really hot air rising off the turbos. It would also help to keep the temperature of the hot part of the iron more uniform, and that would help reduce the thermal stresses that crack the manifold.

Well I have my turbos going back on now, and some extra wrap, I think I'll try it myself. If I want to remove it later I can just take off the heat shields and cut loose the wrapping.

Dave

Tom made me a pattern for making (laying out the strips of wrap) his little blanket just lays right on top and drops down a bit towards the LIM. I have to admitt I was surprised at what a difference it did make. I haven't done mine yet as I have a set of Pettit high flow's going in sometime soon. Jack

if u have the downpipe off, go ahead, if not, dont bother.

i have heard that wrapping intake pipes, while most consider it fugly, decreases intake temps by about 5 degrees, any thoughts?

not too sure about the drop in temperature, but I can rest my hand on my downpipe (single turbo setup) now that it is wrapped. If you don't pay too much for the wrap, and the parts are off of the car then I say go for it. I did my downpipe, and the runners on the resonated midpipe.

i'll tell you what.. I wraped my downpipe a while ago and the stuff began to dry rot so i pulled it completly off.. I cant believe how much warmer it feels in the cockpit! I dont know maybe its the hotter weather but i'm going to rewrap it!

Wrap....definately, if your wrap is rotting you can also spray the wrap with hi heat temp paint (black or silver) and this will help keep contaminates from soaking into the wrap. You can still put your hands on the wrap after a spirited run and not get burned. This may help the rotting problm. Jack

Were did you get the wrap you used?
What brand?
Ebay stuff?
How long before it went bad?

I got mine at Advance Auto. 2" wide x 50'. I plan on wrapping the downpipe as soon as I get rid of the precat.

One of the local speed shops Thermo-Tec 50 ft. roll about a dollar a foot. Jack

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Pro-tip... wear some gloves.
Don't get itchy like I did... :lol: