I have engine out now... Should I wrap the Downpipe
with Themo-tec heat wrap? Before re-install...
What advantages does this have?
And What Disadvantages?
thanks for the replies... jack

 

advantage, it lower engine bay temp = more power
disadvantage, from what i heard it shorten the life of the pipe.

 

Hey thanks for the reply...
But how would it shorten the life of a Downpipe? I have a Stainless steel one from ATR...
And how much HP would I gain? Probally only 2- 5 Hp I imagine...
What's better getting it cermamic coated or to use this Exhaust
heat wrap?
jc

 

I wonder can you wrap it while the downpipe is still on? or do you have to take it out? Also which thermo wrap works the best?

 

Well, I can speak from experience. I used Thermo-Tec header wrap on my stainless steel RP downpipe for a little over 3 years and then got it Jet Hott coated a few months ago.

The reason header wrap can cause problems is if you drive in the rain or allow the wrap to get wet. The moisture gets held in and corrodes the pipe since the thick wrap is slow to try. If you go this route, definitely use a stainless steel DP and not mild steel. I don't drive in the rain so it was no problem but over the years the wrap gets dried out. When I took the DP off a few months back the wrap tore while wiggling it against the frame to get it out of the car. The stainless steel was still in good shape, no corrosion.

I decided to try Jet Hott's 2000-F coating. It cost about $60 and is holding up well. Header wrap was about $30 but won't last as long. I never took temperature readings but it seems like the header wrap reduced temps more (using my hold your hand above the turbo side of the motor method of measurement). You could drive the car and immediately put your hand around the wraped pipe with no burns only warm to the touch, I won't try this with the Jet Hott. Either method is still much cooler than it was with the pre-cat or non-treated DP.

Also, I think the header wrap insulates more noise because it seems louder with the Jet Hott. No perceptable difference in performance of the two methods.

As for putting header wrap while on the car, I wouldn't recommend it. It was a PITA to do with the pipe off and application is critical to it working right and lasting. The wrap must be overlapped and tightly wound.

If I started over again, I'd do the Jet Hott coating.

 

The wrap, especially if applied with a heavy hand, can cause higher temps than you would believe on the pipes, and cause them to essentially errode - or so say a couple of articles out there.

Personally, I like the wrap because it provides some sound dampening, in addition to heat. I had a wrapped DP, then had it jet-hot coated (no wrap) and I could hear the exhaust pulses resonating through it, esp at Idle. So I put wrap back on.

I don't buy the thoery about wet - after you drive your car in the rain, the pipe will be so very hot. And when not driving, it would be pretty hard to get a lot of water on the DP. I think the only real disadvantage on a steal pipe would be winter salt that would collect and *that* could cause some premature rust - but there are good silicone paint sprays to use on your wrap (see summit). On a SS pipe or a ceramic coated pipe there should be no issue at all.

You can wrap about 75% of a DP wile it is on, but not the part closest to the engine.

 

I talked to a rep from swain tec, and he said other coatings (I suppose he means Jet Hot and other types excluding Swain tec coating) are "cosmetic in nature....a few steps above high temp paint mixed with ceramic"...I wonder what the swain tec has over the other coats...does anyone have any experience or hard temp comparisons between different coatings?

The swain tec guy also said rotaries and RV's (believe it or not) are the most difficult to keep coatings from cracking; due to the expansion and contraction of metal under high temps.

Some are also saying SS downpipes are weaker at the flanges, compared to steel ones..anyone have any experience with SS pipes cracking from high temp?