To wrap the DP or not to wrap the DP?
 

Hey all,

I'm getting ready to install my downpipe this weekend, and I was wondering who has wrapped, who has not wrapped, and what harm could come from wrapping or not wrapping your DP.

Thanks in advance!

i did it, it killed the high pitch whine of the turbos, i hated that

i havent wrapped mine yet but im sure its helps with heat no doubt, just wrap it. wrap it up baby!:D

really? thats weird, my friends turbos(who has a wrapped dp") were crazy loud, and i thought it was from the wrapped dp. maybe it depends on the dp?

it's better not to wrap i guess..(juz my.02) it helps coolin the exhaust durin hi speed..

Noise doesn't kill a rotary engine - heat does.

Are you more concerned with how the turbos sound or how long the engine will last?

Be smart here.

I didn't wrap mine, but if given the choice again, I'd definitely wrap it.

Wrong.

We're not interested in cooling the exhaust, we're interested in making sure the exhaust does it job correctly - move exhaust gas out of the car with minimal flow disruption and heat transfer to the rest of the car and in addition aid in scavaging any unsed air/fuel past the exhaust ports.

Well I wrapped the down pipe on my T2. If you wrap your downpipe you will reduce underhood temperatures(not sure how significant of a change), keep the heat energy in the exhaust which will means higher exhaust velocity=less backpressure=more power reduced turbo lag.. (again not sure how significant)
Err.. disadvantage is that people have reported a reduced lifespan of wrapped downpipes, If your dp is stainless steel you don't have to worry about rust... if it's cracks in the welds... don't worry about it, it would probably still last up to 5 years.

true enough, but to me i just like the sound :D

and anyways, my engine didn't last very well at all and my downpipe was wrapped :)

Great replies so far, thanks guys!

Is there any absolute disadvantage to not wrapping (besides the possible slight performance difference)? Specifically, doesn't just adding a DP in and of itself reduce underhood temps by a good 100 degrees? Is there that much more of an additional reduction in heat by wrapping it?

I have an M2 downpipe that I'm installing if it helps (as far as durability goes). I suppose if I decide to wrap it I can just get the materials at a local auto store?

Thanks again!

yea man it corrodes a bit faster, but it does drop temps quite a bit, If it didnt serious racecars and things of that nature wouldnt use it, Its there for a purpose.

-Chris

the place where our dp mounted has potential of air to metal coolin..coolin the dp exhasut(exhasut=heat) is similar concept of wrappin the dp (removin heat) that's what i was thinkin.. but i will choose to wrap the part near the turbo and let the bare metal out coolin where itz sat near the transmision area

Well.. If you wrap it up with 2 layers or just even 1 you can touch the dp without getting burnt.... well.. for a good while that is.. but I don't recommend you do that.

If it were up to me I'd wrap the whole exhaust system from turbo all the way to the exhaust pipe.

As far as cooling goes you only want to reduce underhood temperatures and for the exhaust gasses tuners try to keep the heat energy in it so that exhaust gas velocity will be maximized.

:) u guyz literaly convincin me to wrap that bitch now.. thats why i stay this forum much more the other. u learn every day.. Thanks

Wrap the entire car. Leave the windshield unwrapped so you can still see out. ;)

I wrapped on a small section of my manifold(Single turbo) and my exhaust temps went up over 100C!!!

I'd rather have high underhood temps than have 1000C EGTs:)

Well... if you feel that way... Then you'd rather have higher intake temperatures. and an overall hotter running car.

It doesn't matter really.... if you place your exhaust temperature probe exactly where the exhaust gasses are being expelled from the engine it shouldn't make much of a difference in reading....

Besides exhaust gas temperature readings is only a way to detect fluctuations in A/F ratios and does not really tell you the whole story.... you'd need a wideband for that... I don't have much experience.... well no experience in A/F tuning but I will bet my lunch that you can have similar A/F ratios at different temperatures.

Hotter intake temps can be combatted by having a good FMIC and/or water injection.

My EGT location didn't change....the only thing I did was go from no heatwrap to heatwrap in ONE little itty bitty area because I had an oil return line near the manifold, so I wrapped the manifold to keep the heat from getting to the hose. Prior to this, I would see 920c~ in 4th gear, 9000 rpms. After I heatwrapped, I saw over 1000c in 4th gear, 9000 rpms.

According to my wideband, the a/f are exactly the same as before. HOWEVER...hotter EGTs = bad for engine.

Why?

From my experience a wrapped DP will rust much quicker than an unwrapped DP. I'd get it HPC extreme coated instead.

I agree with that.

If you got the $ go for this: http://www.jet-hot.com/

yeah, but who cares if it rusts? it is only surface rust and will take many, many years to rust through to the point where it needs to be replaced.

Lets make one thing perfectly clear:
- You wrap a downpipe to decrease temps in the engine bay.

Read up on how many posts point to excessive heat causing FD engine failures as well as failure of other related parts such as fuel hoses, the rats nest, brittle vacuum hoses, etc. Fuck it if the downpipe rusts. Its only surface rust and if it does happen to rust all the way through 10 years from now, its a $200 part vs. everything else.

By keeping heat inside the downpipe instead of radiating out onto all the other parts in the engine bay. If jspecracer realized a 100 degree increase in exhaust gases in the downpipe, then that is at least 100 extra degrees cooler underhood.

Thanks dude! I really laughed my ass off to this one! Cooling the exhaust... :weed: