if it sounds raspy it coming from the midpipe, not the header

Yeah I still have the raspy sound too. I'm glad you bumped it, I'm gonna do this this weekend along with welding my clutch.

Not always true Dozer. Racing Beat said it themselves too (just spoke to them on the phone) if the walls of a header are too thin, then it could create some sort of buzz. heat wrap has been known to help but not always.

i dont know if it will fix the sound but i dont think it costs much so why not try :)

will wrapping of the header or midpipe toast the O2 sensors?

Well my rear O2 doesn't work anyway so its of no concern to me. As for wrapping the header I don't know.

Here's word of advice:

I wrapped my previous Miata's header (actually two of them). One was a Maxim Works Header and the other a Racing Beat 4-1 SS Header. Both of them were not your run-of-the-mill ebay header. They had great welds and great construction. After I heat wrapped the headers, over time, they eventually failed at the welds. My other friend who had the same headers (he was a CSP guy and the Maxim Works was popular amongst them) didn't crack his after 5 years of abuse - but he has no wrap.

I can assure you that the surrounding temperatures will go down for sure. However, I'm guessing that the path that the exhausts run need no additional wrap.

If you do have to wrap, make sure to keep 1/4 inch overlap and constantly pull from every angle. You do not want ANY moisture to get in there are start rearing its ugly head.

I just want this wrap so my interior doesn't get so hot. http://www.amazon.com/Floor-Tunnel-S...=3UWO3DNZZD7ZJ

I never thought about moisture (not that we have had any) but i guess I can unwrap it and re-wrap it in a few months.

Dang this stuff is $50.00 at autozone for one roll!!!

team may have some good points, but not all.

the product warns you of voiding header manufacturer's warranty, so take caution.

stay away from this wrap for those using ceramic coated headers. it cracks them for sure, and from personal experience... it does! so the warning is reasonable. just need to not ignore it!

i did not have any problems using it on the mild steel oem headers on my honda, or any stainless steel ones... which is where most bikers use most of this stuff on.

so as long as its not a thin crappy ceramic coated metal... you may be fine. my friend has this stuff on his old 60s bike without any problems on oem mild steel pipes. so its ur call...

stainless steel "should" be more than strong enough to handle it, unless of course, its made from somewhere that doesn't care about quality control and cuts corners. so again, the thickness again may play a role.

i'd surely stay away from ceramic coated ones...

any inputs are welcome if i'm wrong

I will be putting it on my SR midpipe.

Moisture??
Any moisture in the wrap will cook out in the first 5 minutes of you running it. Not to mention that you're actually supposed to soak the wrap before you put it on so you can wrap it better. Moisture shouldn't be an issue.

Good point.

I'm really considering wrapping my midpipe (don't like the rasp), but I've heard both - avoid moisture, and now, not to worry about moisture. :uhh:

I almost imagine that it wouldn't matter too much, since driving the car in the rain will certainly soak the wrap anyways. Hmmmm..

if you really want to wrap the exhaust here are some things i have experienced
1- you will have to replace the wrap at some point.
2- if you wrap too much to close to the o2 sensors--they will not perform correctly. My a/f gauge (LT 1) which has been spot on for a while recently went crazy when i was stuck in traffic--going 3 mph in a 95F day. I dont know about the factory one--car was running ok but i am sure the increased heat was also affecting it some. I had my oem header and midpipe wrapped.
3- after that i unwrapped and installed a heat blanket that is elavated above the pipes by a bracket , i also installed it to shield the trans. I also placed some heat protection on the floorboard part above the pipes. No prob since.
4 heat wrap will make the exhaust gas hotter at the ends and it will be easier to melt the chad close to the exits.
hope my experiences can help someone.
OD

Hmmm. So it will make my tips hotter? I don't have a problem with my shrouds melting and I don't want a problem.

yes it will--especially on the track or autocrossing where you have a more constant wot. The heat has to go somewhere-----?
OD

Even without a wrap,

I've melted my shrouds a tad bit from running in the canyons at a very aggressive pace. Also, my tips were glowing red at the top of the mountain for a tad bit. I also have some of the finish coming off the tip of my MS exhaust.....I think from the constant heat.

I have used both but ceramic coating is a better bet. More expensive if professionally done but lasts alot longer, looks better, doesnt hold moisture and wont have the cracking problem some people get with wrap.

Thats a negative sir.... that is actually the "Second Law" (the third when you consider that thermodynamics contain a "Zeroth" law). And if you want to get into more detail about it, there actually isn't a law that says "hot goes to cold", but moreso details how thanks to entropy, a body cannot spontaneously go from a state of cold to hot.

before deciding what to wrap, research why you shouldn't use wraps in the exhaust system of the renesis engine.... hint: it has something to do with the way the exhaust ports' uniqueness compared to older rotaries.

If the (after wrapping) hotter exhaust picks up velocity, why? It does so because there is greater pressure between the manifold and the tailpipe exit. That greater pressure could be called backpressure ....

that depends on how many strands you want to split a RCH into ...

i dont understand the point of wrapping a header to be honest, and you have to ask yourself exactly what your main purpose is.

For example, why would you increase the velocity of the exhaust ? what is the purpose? No, it will not give you any gain on a renesis. Exhaust wraps main purpose was to improve exhaust scavaging at the header, and considering the renesis is a zero overlap engine ... there really is no point.

Second, like OD said, wrapping the exhaust INCREASES temps at BOTH ends. Now, consider "both ends" of the exhaust... what is on one side? the tips right? so what, you melt a shroud, nothing to cry about ... what is on the other side of the header? The side plates of the rotor housing. Now do a little reading on the renesis engine and realize that the main caveat of its design is that its exhaust flow goes through the side plates ... those side plates thus have a hotter deltaT than the rotor itself. What does that affect? One of the most critical failure points of a side exhaust rotary engine ... the side seals.

Ok fine ... lets just forget about that problem, and lets consider that heat doesn't just magically dissapear (mr 'i quote thermoD but clearly dont know a lick of shit about it). Anyone ever see what an exhaust header gasket looks like after miles of abuse on a wrapped header? you would be surprised how badly it is trashed.

Again, this isn't something new, and has been discussed ad nauseum on this forum. They have even been discussed in VARIOUS books on the renesis engine. Like I said bud, you are retired ... you stated you have plenty of time on your hands .... pick up a good book and do some reading... you would be surprised what the world outside of a "Harley" entails

Increased exhaust velocity is of greatest benefit on Turbo Cars. So really I also don't see the purpose of wrapping our NA cars. Theoretically faster exhaust on our zero back pressure calibrated cars would just be an improvement on overall exhaust flow, BUT from what I have been reading, The Cons of wrapping our exhaust outweigh the PROS.