I'm looking to use some exhaust wrap on my down pipe after it gets some Jet Hot and I wanted to know what size ties I should use: 8 inch or 14 inch ? I think I have a bonez down pipe with 02 bung.

http://www.hrpworld.com/index.cfm?fo...action=product

 

IIRC, you'll want the longer (14" ties) for the 3" downpipe. I believe they were four to a pack. FWIW, I found soaking the wrap in water made it fit a little easier (I think I was using the 2" wide wrap) without folding when trying to go around the O2 bung.

 

Soaking the wrap first is much easier, if its fiberglass, prevents generation of dust too. I doubled wrapped the DP and used only one 4 inch SS hose clamp located near the mid pipe area. Didn't have those wraps, just stretch it tight.

However, I had the engine out at that time. But it can be done under the FD, just a little more effort. Good luck

 

You will want the 14" straps for a 3" downpipe.

 

This is what I'm looking to get from hrpworld.com


DEI-010416 1 3/8" x 30" Cool-Tape

DEI-010301 Black HT Silicone Coating (High Temp Paint)

THT-11152 2" Wide Natural Exhaust Wrap - 2"x 1/16"x 15 ft.

DEI-010202 14" Stainless Steel Locking Ties - 4 Pack

-----

I've read the silicone coating is to help seal the exhaust wrap so it doesn't get contaminated by the elements (oil, fuel, road grime, etc) over time.. not sure how helpful this is, but seems to make sense. Anyone try using it?

The cool tape is for wrapping the new wiring harness (and other odds and ends) that is also being installed, I figure the $20 bucks for the cool tape is a great way to help keep the new harness from getting crispy. Anything helps right?

 

I don't know about soaking it in water first, that kind of fits the bill for all of the horror stories I've heard. Water gets trapped by the wrap and ends up eating right through the metal.

 

eating through ceramic coated stainless steel? or even just plain stainless steel? even after the car is running for a few minutes and the down pipe heats up?

that doesn't make any sense, there must be something else causing the breakdown of the down pipe in whatever stories you've heard.

 

Oh, somehow missed that it was going to be ceramic coated. All of the other stories I've heard just included plain steel. Ceramic coating and then wrapping should be perfectly fine.

 

I think the DEI instructions suggest soaking it to make it more pliable.
FWIW I ran wrap on a mild steel downpipe for nearly 4 yrs. (maybe 30k miles) Just took it off last winter during a rebuild to find some minor pitting, but nothing that comes even close to compromising it's integrity. That said, I sanded it down this time and painted it with the DEI hi-temp paint before new wrap went on. Then I sealed it with more paint. It looks nicer.

 

considering ex. temps frequently go past 800 I dont see a problem with rust.

 

I wouldn't have thought so either, but I've read a lot of posts here and on other boards about the dangers of exhaust wraps. If I have time later, I'll see if I can't search and find some links.

 

I don't disagree that there were many saying not to do it. I probably read the same threads. But I was too lazy to remove my mild steel DP before adding the wrap. I anticipated having to replace my DP with a stainless one after all that time but was surprised on just how little pitting there was. I'm not recommending others do it. Ideally, I think that heat coating AND wrapping, as the OP is doing would be the best way to go.

 

The water makes its easier to wrap it tightly. Its going to all evaporate as soon as the downpipe gets hot anyway. Wear gloves and long sleeves as the fiberglass will irritate your skin.