QuoteI've heard that cars use the wrap to keep under hood temps down and the exhaust gasses hotter so they travel through the long exhaust pipe easier, being less dense.

Scott, I'm not sure about the hotter gasses traveling through the exhaust pipe easier, being less dense.  With steam pipelines at a power plant it's the opposite, the more dense the steam is, the lower the pressure losses in the piping.  If the density becomes less, it results in higher a velocity which in turn  results in higher friction losses.  I suspect that a gas like exhaust gas is similar and if we could somehow cool the exhaust way down in the pipe, the backpressure on the engine would drop.

I think another advantage to wrapping exhaust pipes in cars is to keep more energy available for the turbocharger, if there is one.  About performance advantage on a Duc, I honestly don't know, but I like Atomic410's reason that it saved his boots.   

There is no performance advantage on a Ducati to speak of.

The MAIN hypothetical advantage would be to spread the heat of the exhaust so the entire pipe sheds heat more evenly, however, you will still get hotspots under the wrap and it will prevent wind from cooling them down.

Ceramic coating is the best for spreading and shedding heat, but you do not get any rider protection with ceramic.  The wrap gives much better rider protection.

Another benefit to wrapping the pipes is less heat radiates from the pipes to the rider.  As far as exhaust flow and temperature goes, it is more a convection issue than a density issue.  On our bikes any difference would be something between negligible and none.  Even with a car the biggest gain would be from the reduction of underhood ambient temperature, the benefit being a cooler mixture entering the intake.  Cool dense mixture means more power.

Quote from: howie on January 22, 2009, 09:00:56 AM
 Cool dense mixture means more power.

yep, i have a mister on the intake on my Volvo.  IPD sells them.

i was looking into doing the same thing for the ducati, but it was a lot of complication for little hypothetical performance gain

Quote from: ducatizzzz on January 22, 2009, 09:20:30 AM
yep, i have a mister on the intake on my Volvo.  IPD sells them.

i was looking into doing the same thing for the ducati, but it was a lot of complication for little hypothetical performance gain

What kind of Volvo do you have?  I've got a PHII S40 with the Eurosport Tuning intake and heat shield.  Doing the exhaust wrapping on the Duc just to make everything darker and more sinister.  No performance gain is needed for me, just like the way it looks.

Quote from: Bellagio on January 22, 2009, 12:53:07 PM
What kind of Volvo do you have?  I've got a PHII S40 with the Eurosport Tuning intake and heat shield.  Doing the exhaust wrapping on the Duc just to make everything darker and more sinister.  No performance gain is needed for me, just like the way it looks.

an early '98 S70 T5 with a bunch of IPD upgrades... programmable ECU, turbo, bigger intercooler, and the water mist injector.

i was really surprised at the difference with the aquamist.  i had the new ecu and turbo running and gas mileage went down a bit, but after the mist injector, mpg went up about 5-10% and it felt noticeable different, esp accelerating in high gear -- a lot more available top end power.

and i do have my engine compartment pipes wrapped, mainly the turbo feeds as they get pretty damn hot.

http://smg.photobucket.com/albums/v720/ctkurt/?albumview=grid&fullsize=IMG00004.jpg

CTKurt,  That is a good looking bike and the pipe wrap really fits with it.  What a monster should look like.

CT- I'm a fan of how it loos with the header just silicone coated.  I think I just need to spray mine up instead of buying more wrap.  It looks very finished.

Ok, I'm gonna pipe in here folks. (pardon the pun!) While I am a newbie to this forum, I have drag raced Harleys for over 10 years and have a National Championship to show for it. Wrapping your pipes is the WORST thing you can do to a street motorcycle's exhaust system. While it has a purpose for drag bikes, they are raced on a prepped track and never in the rain. Water and minerals from the street will eventually work their way through the wrap and eat your pipe away. Unless you plan on replacing your system every 2 years, you are MUCH better off coating them with a ceramic coating like those offered by Jet Hot or HPC. Heat retention can improve exhaust velocity, but a ceramic coating is much more efficient at it, and it reduces the pipes skin temp at the same time, reducing thermal fatigue. A wrapped pipe will disintegrate for a number of reasons, including thermal fatigue and corrosion, and since it is wrapped, you can't see it happening. Ride on the street with wrapped pipes, and one day you'll have pieces falling off of your bike like limbs off the Black Knight in The Holy Grail!

GREAT Information.

Quote from: MadDaddy on January 23, 2009, 12:33:46 AM
Ride on the street with wrapped pipes, and one day you'll have pieces falling off of your bike like limbs off the Black Knight in The Holy Grail!

..so it will be just like having a vintage Ducati!

Thanks for the input Dad.  It took me hella long to get the pipes wrapped, so I'm going to ride around for at least one season with it.  After this year I'll end up cutting it off, def don't want to have to replace the pipes.

Quote from: MadDaddy on January 23, 2009, 12:33:46 AM
Ok, I'm gonna pipe in here folks. .... A wrapped pipe will disintegrate for a number of reasons, including thermal fatigue and corrosion, and since it is wrapped, you can't see it happening. Ride on the street with wrapped pipes, and one day you'll have pieces falling off of your bike like limbs off the Black Knight in The Holy Grail!

Thats like a pretty good definitive answer, which I like to hear.

If one were set on wrapping their pipes, could they be ceramic coated or some other corrosion resistant coating first? Then wrapped, and be assured that there pipes will hold together. 

Quote from: OverCaffeinated on January 23, 2009, 08:50:49 AM
Thats like a pretty good definitive answer, which I like to hear.

If one were set on wrapping their pipes, could they be ceramic coated or some other corrosion resistant coating first? Then wrapped, and be assured that there pipes will hold together. 

It would probably help some, but even the ceramic coating will corrode off eventually.  It just gives you a bigger range of "error" so to speak.  Quality of coatings vary too.  I have seen the under-pipe rust thru on some bikes, but that was the part of the pipe directly exposed to the road and it was probably smacked up wit ha lot of gravel.