header wrap or ceramic coating 034 down-pipes???

[Tarmac]

Header wrap is getting a bad "wrap". Are header exhaust heat wrap the reason pipes crack from heat. It is really more an issue of alloy quality used by the manufacturer of the exhaust system.
I'm not certain which Stainless Steel is used for the 034 MotorSport 3" down-pipes?

& dose Ceramic coatings reduce as much heat as a header insulating wrap does? I'm tossing which way to go, Heat wrap or Ceramic coating?????

I took my intake manifold in to get ceramic coated & the business owner advised me not to heat wrap my 034 3" down pipes because in time they will crack?
I understand he's advise is expected but a lot of people are starting to share the same views (wrap them & they will crack)!!!

Both industries seem to be having this on going heated argument. Is this an argument with one outcome, Agree to disagree

Has anyone had headers or exhaust down-pipes cracked due to heat wrap?

[diabolical1]

i've heard many times that wrapping manifolds (due to probable cracking) is bad. however, so far, i haven't heard anyone advise against wrapping downpipes.

[Razorecko]

i coated my old dp (mr2 turbo) in black bbq paint =) worked fine. The only benefit i see to coating a dp is if its close to your trans pan or electrical wiring that's sensitive to heat. Outside of that leave it be for best heat dissipation

[Zba]

I recall reading somewhere that using the wraps traps moisture and eventually leads to corrosion and cracking. Can anyone corroborate this?

[Dubluv11]

i have heard of headers and manifolds cracking...not downpipes though...but i'd imagine the downpipes of a turbocharged car would get jjust as hot if not hotter than the headers or manifold of a non turbo'd car... i'd just leave them be buddy, if they were meant to be wrapped or coated...the stock ones would be from factory.

[diabolical1]

Outside of that leave it be for best heat dissipation

i would think you'd want to keep the heat for better velocity.

... if they were meant to be wrapped or coated...the stock ones would be from factory.

not true. i doubt the manufacturers are going to go above and beyond whatever it takes to get the car to meet noise requirements and emissions.

[Dubluv11]

header wrap has nothing to do with noise requirements...nor emissions..

if you're talking about those 2 things aside from this topic, then yes, they do actualy.. they use glues and foams underneath your carpet to reduce road noise, they use 4 cats on the s4...2 are just precats and the reason for those cats is to warm the car up to operating temperature sooner so if you need heat you get it faster... VAG group does things for the benefit of the consumer that most other companies ike gm would never think of...or implement them about 4 or 5 years after VAG has already been using them

[Dubluv11]

they do go above and beyond the expectations for road noise, ride quality, emissions, and comfort of the consumer because they want people to continue buying them...
my s4 is 10 years old with 280 000 km on it and it passed ontario emissions standards like a brand new vehicle... when i go over bumps in my lowered car i hear no rattles or vibrations, no clicks, ticks, knocks, or thuds. these cars are designed for quality and comfort and built to last IMO...

[Mott Power]

I would say it's the installers fault if these problems are happening. Most header wrap SHOULD be coated with a high temperature ceramic paint to insure moisture doesn't get inside. I could see the possibility of it happening on the cast headers, but not on DP's if done correctly; at that point I would say it's poor craftsmanship (granted it happens at the welds).

[MacDaddy]

I would prefer to ceramic coat personally, but if i was on a budget i would wrap them.

as far as people saying to do nothing, i think thats a terrible idea, when i did piggie pipes my engine bay became significantly cooler and made the car a little more consistent. Everyone goes on about bigger intercoolers and all this stuff, but never think of the other things which are creating heat and working against their big $1000+ intercoolers.

I say if you got the money coat them, if your cheap wrap them. A cooler engine bay is something every S4 needs.

[Dubluv11]

is it really worth the risk to potentially crack something thats costs me 1000? thats the way i look at it... if i was guaranteed that they wont crack or corrode... then i'd do it..

[Tarmac]

I would prefer to ceramic coat personally, but if i was on a budget i would wrap them.

as far as people saying to do nothing, i think thats a terrible idea, when i did piggie pipes my engine bay became significantly cooler and made the car a little more consistent. Everyone goes on about bigger intercoolers and all this stuff, but never think of the other things which are creating heat and working against their big $1000+ intercoolers.

I say if you got the money coat them, if your cheap wrap them. A cooler engine bay is something every S4 needs.

I'm from Australia & to coat the 034 DP's will cost me $300 each. (not including the mid pipes) Keep the heat in is a good idea but will they crack nobody really knows. As you guys say, is it really worth the risk to potentially crack something that's costs me well over a $1000 bucks? I need to weigh it up, if I keep the heat, will this give me more HP?

[Raacerx]

Its stainless steel dude. Its not going to corrode. Wrap will technically trap moisture sometimes. Stock manifolds are not stainless, and theoretically could be more susceptible to corroding. Me? I am wrapping my downpipes, ceramic coated manifolds, bi pipes, inlet pipes, and outlet pipes. Im sorry but there is never a point where heat is going to help. I will gladly take the insignificant amount of velocity change you might have with a few hundred degrees in temp differences, to get the benefits and advantages of an engine bay that sees that much less heat. Heat is a huge enemy to our S4's. It doesn't help. There is plenty of evidence floating around showing the benefits of cooler engine bay temps, and therefore cooler intake temps and oil temps and overall increase in longevity. There is very little data supporting the amount of power increase or spool time you see with any "increased" velocity of the exhaust gases in the short and small exhaust manifolds.

Also, were not talking about stock manifold or SSAC/OBX gauge metal. 034 and RAI DP's are made from standard gauge stainless; which is like three times the thickness of cheap Chinese crap or OEM. Manifolds maybe you worry. Downpipes, you do not. Wrap and coat them if you can afford it; otherwise do whatever is cheapest and most effective in your point of view.

PS. I saw drastically decreased engine bay temps with kevlar wrapped SSAC 2.5" downpipes compared to OEM piggie pipes and heat shields.

[Tarmac]

I've got the DEI Titanium Exhaust Wrap made from pulverized lava rock and can stand 1800 degrees directly. OK, so I should wrap the DP's. Your correct in saying the 034 DP's are a top quality product & what about the mid pipes, you guys think any benefits there?

[GarbatyA4]

I wrapped my 3" DP on my 1.8T... Had No issues.

DP's will be fine. Its amazing how well the stuff works. AFter moderate driving... i let my car stand for a couple minutes. The tape is warm to touch. Keeps heat in and keeps exhaust velocity up :)

The moisture aspect? lol Do you honestly think moisture will trap in the tape thats in contact to the exhaust. Think about it boys.

ps. You're supposed to soak and wring the header tape in water before you wrap

[Tarmac]

I got this from the DEI web site re the (DEI Titanium Exhaust Wrap)

Why only a ¼" overlap, isn't more overlap better?

More is not always better when it comes to exhaust wrap. You can hold too much heat in the tubing
and manifold to the point of changing the molecular structure of the metal. This can cause premature
wear of the tubes or fractured welds. Overlapping ¼" is receommended as this allows just enough
heat to emit.

[Tarmac]

And this...........The moisture aspect?

Will wrapping my exhaust pipes make it rust?

If the exhaust pipe is made of mild steel, it may rust over time with or without exhaust wrap. If you are
going to wrap any kind of steel pipe we recommend using DEI HT Silicone Coating to spray the header
or pipes prior to applying Titanium exhaust wrap. However, there is no need to apply DEI HT
Silicone Coating to Titanium wrap.

[BlackS4TT(Josh)]

I got this from the DEI web site re the (DEI Titanium Exhaust Wrap)

Why only a ¼" overlap, isn't more overlap better?

More is not always better when it comes to exhaust wrap. You can hold too much heat in the tubing
and manifold to the point of changing the molecular structure of the metal. This can cause premature
wear of the tubes or fractured welds. Overlapping ¼" is receommended as this allows just enough
heat to emit.

Great point. Assuming the heat cylces of the DP result in complete heat treatment of the steel... unwrapped pipes would normalize the metal, and heavily wrapped pipes would full anneal it. While normalizing results in a higher strength material, both treatments increase ductility. Therefore, I don't see how this would cause a brittle fracture. I don't know much about welding, but maybe the welds can't handle the process?

Need a materials expert here!

[DiscoPotato]

I recall reading somewhere that using the wraps traps moisture and eventually leads to corrosion and cracking. Can anyone corroborate this?

I beleive I have heard this somewhere...

[diabolical1]

header wrap has nothing to do with noise requirements...nor emissions..

you're right, but in my defense, i never said they did. perhaps it's just the way i stated my point that is the problem. i was simply saying, that the manufacturers' concerns with exhaust (and exhaust tuning) pretty much stop at those two things. unless design constraints lead to some sort of other potential issue (like jeopardizing wiring or something of that nature) i can't them using exhaust wrap or ceramic or any other thermal coating.

[MacDaddy]

why not just ask 034? they know the thickeness of the metal used in their downpipes, I'm sure they have a better idea than anyone here if they are going to crack or not.

[Tarmac]

why not just ask 034? they know the thickeness of the metal used in their downpipes, I'm sure they have a better idea than anyone here if they are going to crack or not.

Yes true...... but the awnser will almost be predictable.....something like ("they will never crack") But you are right, 034 customer service is excellent & I should give them the benifet, will send an emai ASAP and askl!!

Just think if they handed out a guarantee aganst cracks on those 3" pipes when wraped, haha that would be nice....

[Zstudd]

i talked to my mechanic who's been working on euopean cars for thousand's of years and i asked him the same about wrapping my dp's. he said it's a toss up and has alot to do with the materials in the piping. could crack or might not. i don't wanna take the chance so decided against it. i just have the ceramic coated exhaust manifold and calling it done.