Triumphrat

MGD

I as many other Sprint ST 05-06 owners have a little bit of an issue with the heat that radiates along the right leg and through the seat. So I was thinking about wrapping the whole length of pipe, all the way to the can, with header-wrappings.

Now.. one of my colleagues say, good idea, just go ahead, it will make exhaust fumes hotter, travel faster, and be more efficient.

The other colleague tho.. he say that if I wrap the whole way from engine to can the heat will have no place to go and will creep back to the cylinder and top with risk for overheating.

Anyone have some real info about this?? :???:

MickMaguire

Just speculating, but I dont feel the latter has much substance. You could always leave the top few inches bare.

I might be more a little more worried about any possible effects of the extra heat on the oxygen sensor in the ehaust though.

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Mick...

MGD

Hmm, never even thought of that, how much do you think it could affect the sensor? Could it even damage it?

MickMaguire

I have no idea, its just speculation

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raproe

I saw a Harley with header wraps a few weeks ago. The heat had no place to go so his mufflers had actually turned blue. :wow:

On a more serious note:
The hotter exhaust does three things. First, as your colleague says, it makes the exhaust travel faster. But, since flow resistance rises as the square of the exhaust velocity, the higher velocity increases the flow resistance...just like you added a baffle to the muffler. That is not a good thing since the engine spends extra work to push the exhaust through that resistance and that work doesn't go to the wheels.

Second, the increased heat increases the speed of the exhaust waves in the exhaust and changes the rpm's (upward) where the engine gets the best scavenging. That can be a good or bad thing depending on the tuning of the rest of the engine setup.

Third, the scavenged exhaust that goes back into the engine is hotter. That means the exhaust valves and cylinder head will indeed run hotter. The oxygen sensor gets that extra heat as well. That's not a good thing either.

The bottom line is two out of three bad things will happen and, unless you mess around with a dyno or have some good simulation software, you can't tell about the third. It may give enough improvement to overcome the two bad things or it may also make it worse.



[ This message was edited by: raproe on 2006-07-26 18:04 ]

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MGD

Ok, starting to look like I should look deeper into this issue before I don anything.

I actually do not look for any "more power", rather, it´s only about getting rid of some of the heat radiating off the rear part of the pipes.

I don't have any problem if the only issue is the muffler turning blue.

That is from around the foot up to the silencer.

Only wrapping the rear half of the pipes would then move quite some heat forward if I understand it right, and there seem to be enough of that under the fairings already.

bigern2300

I've seen disclaimers from automotive header manufatures that warn against the use of header wrap. They claim the heat retention could cause metal fatuige/failure. Obvouisly, we are talking about a somewhat less heat on a motorcycle exhaust system, but just a thought.

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glw

I used it on my 05 R3 and it was never a problem, I am not sure how much it helped, but probably around 20% better. No discolor of pipes or any other problems arose from this.
My 06 R3 Classic seems much worse (hotter maybe due to cat still on and full) so am thinking about doing that one also. (and removing the cat again)
The heat shield clamps that are on the 3 pipes that come off the engine wont fit anymore though so you need to attach those heat shields with hose clamps. You can hide them pretty good though so you dont see them.
They will smoke a little the first time they get wet, but not for long and it didnt hurt anything. "Be Cool" has some about an inch wide or you can also get 2inch wide but it was easier to do it with one inch. they also have black or tan color. Get it at any speed shop.Try it, it wont hurt nothing.. good luck.

chefjpd

Coming from a car performance point of view (basically the same as bike), the exhaust wrap does not, and cannot make the exhaust gasses run hotter. They cannot get any hotter than the initial exhaust port temperature. All it does is prevent heat radiation through the header pipes. The only thing that will run hotter is the temperature of the exiting exhaust gasses.
The exhaust gas loses heat when they flow through the header pipes, so at the exhaust outlet, the temperature is decreased. There is no way for the header weap to introduce more heat into the system.
As far as the O2 sensor, you cannot damage it with standard exhaust gas temperatures, they function best when hot as it is. The same for the Cats, they are more efficient as they get hotter.
So if you can reduce your radiated temperature on your legs, there is no real negative to the wrap.

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Darkhart

I assume that this would also apply to powder coating the Pipes? as I under stand it, this it would do the same as wrapping the Pipes.