So I've paid up for a nice stainless downpipe. Did some searches and there's a lot of talk about wrapping them.



Is there really that much underhood-heat-reduction benefit from wrapping? The biggest thing would have to be just getting the precat out of there. Is there really a big benefit from the wrapping the downpipe also? This pipe is really a nice piece of work, I guess I would prefer not to wrap it and I'm trying to justify not . . . but if I get some really good pro wrap arguments, I guess I'll do it. Also, any reasons not to wrap?

i always wrap the dps and manifolds. even ceramic coated units. i knoticed a 10deg drop in oil temp after wraping the manifold and a slight drop in water temp specialy in stop and go traffic. my biggest drop came from venting the hood.

Here's my "pro" argument.......

It's effective at keeping underhood heat down to something just cooler than molten lead. Remember that a rotory engine exhaust is about 30% hotter than a typical piston counterpart. Obviously stainless won't rust, but it does nothing to reduce the radiant heat, which will bake all the plastics, solenoids etc. The more you can keep the heatsoak and baking down...the better for everything. It's relatively cheap, easy to do (particularly if the DP is off the car) and there's even a marginal performance benefit...although I can't imagine you'll be able to tell. It also tends to quiet the exaust a little too IMO.



Several years ago I did mine in DEI 2" wrap and sealed it with their silcone sealant/paint. http://www.designengineering.com/pro...asp?m=sc&cid=3

One roll is plenty for the DP, even overlapping 50%. I had enough left over to do the inlet and outlet of my hi-flow cat. Together it also significantly reduced radiant heat to my transmission casing and inside the car via the tunnel. In additon to "sealing" the wrap, that silcone coating keeps you from getting ichy if you ever have to work around it. IMHO, forget their ties and just buy some decent stainless worm-gear clamps. Fold the ends of the wrap into a "point" or "triangle" for a cleaner look.



FWIW, in July I can get off the freeway and pull into my shop. In the time it takes to run it up on the lift I can grab the wrapped downpipe with my bare hands. I doubt you could do that with just heat-coating.



My "con" argument........



It's a minor PITA to wrap the DP on the car, and you can't get right up to the flange at the engine end because of the bend. You have to wear rubber gloves, a long-sleeve shirt and eye protection while doing it. It's really a PITA to apply the sealant with the DP on the car. It's not as pretty as heat-coating.

All the stuff will run you about $80.

Ok, sounds like the benefit from the wrapping is significant and my DP isn't on yet, so I'm going to do it.



Thanks both of you for the advice.

Post up any tips you come up with and some pictures if you have time.

Should I post pictures onto this thread or is there someplace better where people can find it.



I had been hoping to find some pictures of finished wraps but didn't in searches. When I looked in the garage area there didn't seem to be any way to do a search for a specific modification. I looked at a few cars in there but didn't find any downpipe pictures. If there are any in there it looked like it would take a car by car hunt checking each for mod pictures, tedious.

banzai-racing.com. go to their cars and check out their FD. he has a single turbo 20b and the downpipe's wrapped if you're looking to see what it should look like

I wrapped mine & am glad I did. Will have to agree with others who have said it tended to keep underhood temps down.



Something else I do. After I have been out driving around in mine for awhile & pull into my garage at home, I pop the hood & let the car cool down that way. I figure that at least the wiring harness, solenoids & control stuff under the hood won`t bake nearly as bad & possibly last longer. Just what I do anyway. I spent too much time, money & effort to not try & take care of my car. I really enjoy driving it & want it to be as trouble free as possible.



YMMV.

Yeah, just post then up here in your thread.



I wouldn't worry about pictures. Fortunately the FD DP has no weird curves and is pretty straight-forward. I think the instructions suggest soaking the wrap in water to make it more pliable. I never did that because I didn't want to wait for it to dry before spaying on the sealant, but it probably would have helped.

I'll look at that. It doesn't seem like it would be that difficult but since I've never wrapped any exhaust I have been wanting to see an example before I start.



thanks