Downpipe Wrap -- Good or Bad?
 

I have a turbo FB with a GT35R and 3" 304SS downpipe. There are some components that are close to the downpipe (like the aluminum part of my wastegate), and I don't want to fry them. I've also heard that wrap can shorten the life of exhaust tubing.

Experiences and opinions?

What kind of wrap is best? There's the generic fiberglass stuff (1200 deg continuous), then there's "Inferno Wrap", which is supposed to be good to 2000 deg continuous.

cheap or generic wrap degrades over time and falls appart....sort of like insulation in a kiln. if you have stainless tubing, the life shouldnt be shortened at all. just dont overwrap it, and dont wrap ALL the way to the wastegate...maybe save an inch or two.

i have my whole DP wraped, it is the DEI brand, no problems.

If you have a mild steel or aluminized downpipe the fiberglass acts like a sponge to water and moisture. It will rot it out eventually. I'll say that the benefits outweigh the negative points. If you're running a stainless downpipe there's no drawback.

Ceramic coating.

You are better off using a high temp coating. I had my mine done a few years ago and never had any issues. I used www.hpcoatings.com and loved their work.

Did you apply the coating to the outside or inside?

To manifold, turbine housing, downpipe?

Elwood, I'll be dropping off my manifold, turbine housing and downpipe off at HP-Powder-Coatings in the next few weeks. They're going to ceramic coat mine in and out. Check them out, they're local. http://webpages.charter.net/rnmhrd/

He uses the Techline Turbo-X Brand.

Hey, thanks for the tip. I got an e-mail back from HP, and their tech rep also suggested inside and outside. He did, however, say that they wouldn't do the inside of manifolds upstream of turbos (and I'm assuming they won't do the inside of turbine housings either) because of the fear of delaminated pieces taking out the turbine.

How much does this stuff lower the surface temp, assuming I coat it inside and outside?

It reduces radiant temps not so much surfice temps!

Best way to reduce the surface temp is wrap. Also, given that the surface temp is reduced further by wrapping, the radiant heat will also go down further as well.

There's numerous ways to reduce heat, as well as reduce its presence in unwanted areas. I like to apply the same thinking as when building a house...for example, 2X6 insulated walls will work better the 2x4 insulated walls. You can also use shielding and reflective aluminum foils to reduce radiant heat's effect on the parts you'd like to keep cool.

I had mine done on the ouside & inside of the pipes

I spoke with a few tuners about this, and their general feeling is that the temperature capability of 304SS is already marginal for a boosted rotary. Adding wrap will hold the heat in and increase tubing temperatures, making the system more likely to fail.

Following this same train of thought, it makes sense to coat the inside of a 304SS system, but leave the outside uncoated, so it will reject heat faster and stay cooler. The real downside I see with coatings is that most of them will gradually wear away -- but that takes a long time (3 + years of heavy use according to HPC).

I'm going to use localized heat shields -- all the OEMs can't be wrong :).

They cant be wrong but they can be cheap! I'm thinking about getting mine coated and then wraping them. That is what i'm thinking. However mine is all mild steel. With the exception of a bend or two in the downpipe.

I've got over 30,000km's on my heat wrapped (cast) manifold and (ss) downpipe.........For what its worth. I'm going to be wrapping my SS manifold when it goes on as well, I've been through alot of setups and I've never had an issue from wrapping. Don't know much, but I know what HASN'T failed on my setup :)

ive seen ceramic coated manifolds on a evo i work on start to flake in months....i guess just make sure whoever does the coating, does good work..good work usually (and unfortunately) means more money though

those that say the wrap will hold moisture- once you start the motor that moisture will burn right off.

Way I see it is if wrapping the pipe means I might need a new downpipe a little sooner so be it, its worth it for the comfort of not being baked to death in the car and to protect those things around it.
Think about it- a downpipe is probably the cheapest thing in your car and one of the easiest to replace- besides most people end up changing set ups or motors anyhow and never see the full life span of the part.

Im going to wrap more of my exaust, im sick of the heat in the car- also going to put heat shielding under the floorboard.

Yea my vert gets real hot inside too. I just had my downpipe, manifold, UIM LIM, and all my intercooler piping ceramic coated. It helped a little but not as much as i would have hoped. I plan on wrapping my downpipe on top of the ceramic coating. Also will be putting the DEI sheets with adhesive on the heat shields underneith. Hopefully that takes care of some of my heat problems.