Quoted for truth.

 

If there is an OReilly's or similar near you I know they carry it. I saw some yesterday behind the counter for sale at the one down the street from my house.

 

I know of 2 stores that sell it. I'm going 2morrow

 

^Disagree Adam. Wasn't like all of a sudden I'm driving an NA....but it did make a noticible difference on my car. And it significantly reduced the radiant heat to the transmission tunnel too. It was worth the $50 or so and my time.

 

just for reference, here's a pic of my old wrapped downpipe vs my new jethot coated downpipe...

the wrapped downpipe had a random tech high-flow cat welded into it, that's why it has a "bump" in the middle.

 

*off topic* I had my downpipe coated with jet-coating or something, I touched my downpipe with my finger tip and my skin turned white and gave one of the worst burns in my life, lucky it wasn't too serious.

soaking the wrap in water would make the wrap conform easier.

 

^ thats third degree. and what the hell were u thinking? a thin coating of paint was gonna protect u? i'm afraid to touch a turbo heat blanket let alone bare metal... lol

 

there is 2 different wrap that Dei selling. so which one you guys use to wrap it?


Titanium Wrap with LR Technology

http://www.designengineering.com/pro...sp?m=sp&pid=95

and this:


Exhaust / Header Wrap
http://www.designengineering.com/pro...asp?m=sp&pid=9

so which is which..? anyone ?thanks

 

^^^^ good ? i saw the same thing when i visited the site. i would like to know if anyone has any experience with the new stuff, or if they are just jumping on the titanium bandwagon to sell my product.

 

Jim, The turbos produce XX amount of heat. If it isn't radiating off your DP, it is coming off somewhere else. It doesn't disappear. When the car is moving, normal airflow will move radiant heat from an unwrapped DP very quickly. Radiant heat is likely only a factor at idle.

I don't know the physics about improved performance from wrapping. It doesn't make any sense to me that there would be a measurable gain. However, I will take your word that it does do something.

 

The hotter the exhaust tem is the more velocity it has. This makes more power and spools turbos faster. By keeping the heat inside the pipe keeps the velocity up as high as possible.

 

Actually after the turbo, that does not apply. A freezing downpipe would be preferred. Backpressure after the turbo is undesirable.

thewird

 

I don't know what you're trying to say here. I agree backpressure is undesirable, however Dudemaan was %100 correct.

 

Correct - you want to use all the energy (heat & pressure) you can in the turbos, not dissipate or expel it afterwards. However, wrapping is not in vain - it keeps everything surrounding the pipe cooler, including the engine compartment.

 

I still don't understand how wrapping your dp has anything to do with what thewird or Dave w are saying. Keeping heat (exhaust energy) in the dp (by wrapping or coating it) only serves to increase velocity which reduces backpressure in the manifold which makes your turbo more efficient. Agree?

 

Bought my thermal wrap online, here. The 15-ft roll was barely sufficient for my 3" Bonez S/S DP. I didn't coat either the old wrap (which ripped off eventually) or the new one. No indication of bad effect on the DP from the old wrap.

Higher heat in the exhaust pipe raises the pressure of the gases leaving the engine. The increased pressure of the gases does increase their exit velocity. But the increased back pressure is not desirable. This is why one goes to a larger diameter pipe... to decrease back pressure. It's not really velocity that is a driving factor... for minimum back pressure the exhaust port would be open and not exit into a pipe, and the velocity of the exit gases would drop extremely fast once out of the port. There would be zero back pressure and the turbos would be as happy as possible.

 

The TURBO hotside velocity is increased due higher pressures as a result of keeping the heat in the TURBO. Creating higher pressures in the downpipe due to extra heat is will REDUCE TURBO VELOCITY which is the opposite of what you would want.

Wrapping the downpipe is generally a good thing though as it keeps heat away from other things, however it has nothing to due with velocity.

thewird

 

just bought the wrap kit off ebay, the store i went to sold only the wrap and no ties or spray.....

Exhaust / Header Wrap Kit - with Black HT Silicone Coating $122.85

ebay, $87. shipped for the same thing

 

That's fine, but you make that assumption that backpressure will rise due to the added velocity, which would only be true if the downpipe is not large enough to support the added velocity. Extra heat is not created, it just redirected. I am reffering to a 3" single turbo downpipe.
My main arguement here is that wrapping or coating your downpipe will have ZERO negative effects on manifold backpressure.

 

so the lesson of the story...

Wrap the DP to protect everything else in the engine bay, especially the part of the harness that extends across the top of it... which I would (and did) wrap in some heat shielding.

This is the same reason why single turbo's have heat blankets... right? Otherwise who would put one on?

 

I'm 100% sure its not noticeable but if there was a way to accurately measure it, wrapping the downpipe actually has a negative effect on exhaust flow at the turbo. Using the argument, that if your exhaust is big enough, doesn't count since your using size to compensate for lack of efficienct. Besides a full 3" exhaust will still have backpressure on a decent horsepower rotary. I'm making 415 rwhp on a Mustang dyno with the 500R-SP and had 11 PSi of backpressure with the Racing Beat dual-tip catback and it dropped to 3 PSi when I installed a full 3" titanium canister.

Don't get me wrong, wrapping the downpipe is generally a good idea to keep the heat where it belongs. However, I want to make sure its understood that the wrapping's only positive benifit is keeping the heat away from other things. And depending on the position of your turbo, it might not even matter.

If I were to build a race car I would not use wrap, only a turbo blanket.

A turbo blanket actually provides some positive benefit as it keeps more energy in the turbo. And keeps the turbo from superheating the air around it.

thewird

 

can anyone tell me the different in this 2?

thanks

 

the difference between the 2 are ones made of lava something, and you dont need to wet it to put it on. and it gives it a carbon fiber look.

 

The added velocity is because at any given pressure, gasses expand in proportion to the absolute temperature. So if the exhaust is hotter, it takes up more volume, and needs to flow at a higher velocity so it doesn't stack up. Since it has to flow faster, more backpressure is generated by the increased flow velocity (viscous drag through the pipe). Any size pipe will still cause more backpressure as the flow is increased. If the pipe is large enough, the backpressure becomes so small it can be hard to measure the difference. Remember, a higher flow HAS TO BE FORCED through the pipe by a higher inlet pressure (backpressure at the turbos). This effect is present all the way to the end of the exhaust system. So, if the exhaust is kept hotter early, it will generate more backpressure all the way through the system.

It's not much different from air flowing through a hose - more volume of flow means higher velocity, and also means a greater inlet pressure (backpressure) needed to move it.

Dave

 

^ Better explanation hehe.

thewird