Exhuast Wrap?

raventai · October 21, 2003

last allison fluid change I noticed how much of that tranny is surrounded by exhuast pipe, I am thinking it may help out with tempratures to keep this area cooler,

found a good price on soem plain fiberglass wrap (good to 1000 degrees)

http://store.hamiltonmarine.com/browse.cfm/4,5654.html

there is other stuff marketed to the racing croud that is rated for higher tempratures but it is quite a bit more expensive, I dont think the exhuast gets over 1k degrees on this truck

suposedly keeping ht eexhuast gas hotter allows it to escape easier giving better power

waht will the cats and O2 sensors think of higher tempratures? the cat will just burn cleaner right?

CMNTMXR81 · October 21, 2003

The only time it will matter for the cats is on initial heat up. The quicker you "light off" the cats, the quicker the truck gets into closed loop operation and the closer to stoich it'll run. Afterwords, it won't make any difference at all.

But I agree, heat wrap may be a good idea. We do have some big plumbing down there, but remember, being a higher truck, we also get a lot of airflow under there, so it may not be that critical.

How much is header wrap from Summit or Jegs?

raventai · October 21, 2003

Cool that makes sense, most places want about $30 for 50' the marine place only want 16 for 100' (+10$ shipping) I am going to see what I can get locally for fiberglass cloth tape at a glass supply house

http://store.summitracing.com/default.asp?...=both&part=wrap

summit is even more expensive

similar at Jegs

http://www.jegs.com/cgi-bin/ncommerce3/Pro...351&prmenbr=361

I have been reading and supposedly it can be a place for moisture to collect and cause corrosion, I think I the combo of high use my truck gets and stainless exhaust will keep me from having any problems,

and if you say the emissions stuff should be OK with it I think we are go now I just gotta buy it

Thanks

raventai · October 21, 2003

http://www.boilerroomsupplies.com/boilerga...ist.html#t-tape

here is some more cheap and in may sizes but I would have to buy $100 worth

might be good for group buy

edit 50$ here

http://www.theboilerman.com/gaskets/boiler...t.html#ind-tape

edit again I ordered form the boiler man and she said they have a 100$ minimum but they will let me in for a one time order of 50, ordered 100' roll of the 2"x1/8" for the exhaust system and 100' roll of 1¼x1/8" for use on the exhaust manifolds if the rest works out well

if anyone does the same get the plain do not get the "drop warp" it has missing cloth in the middle for nstalling bolts through it when used as a gasket

MCourson · October 21, 2003

I would have to say becareful with wrapping the exhaust. We used to have to wrap our exhaust pipes on the kart but the wrap would trap the heat in (and we run methanol which burns a lot cooler than gas) and every 2 races or so we would be replacing pipes due to them cracking and breaking. Even though it is technically illegal for our rules (even though there is no performance gain) we quit wrapping the pipes to save them, havent lost one since.

raventai · October 22, 2003

ouch! do you think higher temps will cause this large diameter stainless exhaust problems?

raventai · October 22, 2003

ouch! do you think higher temps will cause this exhaust to have the same problem?

CMNTMXR81 · October 22, 2003

Can't say about the higher temps cracking them. I know they've used this type of stuff up on headers since the 50's and it's hotter there. I wouldn't worry about the corrsion thing due to moisture if you drive the truck long enough to get the pipes up to full operating temp long enough to dry them. If you take short trips, it may be an issue.

And yes, the sooner you get the PCM into closed loop mode, the quicker it'll bring the O2 sensors online to monitor A/F and to stoich. Up until then it purposely runs rich in an open loop mode (ignoring input from the O2's) similar to a speed density set up.

So in theory, wrapping them, increasing the heat, therefore lighting off the cats sooner is a good thing. Some of our 8.1's have an A.I.R. system (mine doesn't) that basically injects air into the exhaust stream at the manifold to help speed up that switchover to closed loop.