Well after i swapped out my hks down pipe for my 4 1/2 monster i was a little dissapointed with the lag the massive pipe created. the factory heat shield would not fit and the aftermarket only fit the 3 inch pipes. so after pondering cutting my stocker wich i dont think would ever have worker i decided to wrap it in header wrap. what a world of difference, after letting the car idle for 30+ mins you can grap the wrap with your hands for about 10-15 secs before it gets uncomfortable. all lag seems to be gone, cars back and running great again. just wanted to vent, if anyone is having the same problems

 

Yea i wrapped the entire down pipe from top to dottom.I think its dts dst something like that. its the 2x50 roll. it was like 40. and worth every penny

 

who makes a 4.5inch downpipe?

 

I got it at bullfrog performance in zephyrhills, but im sure thay have it at any old school performance shop. Its just header wrap but make sure you get the 2x50 roll. the 1 inch wont be enough to make it to the bottom.

The downpipe i purchased was some freak deal off ebay, its a stainless steel bellomoth like like the turbo xs 4 inch but a 1/2 inch wider. the seller told me it came from over seas when was stationed there in the military he picked it up for his then wrx. but ended up getting a new car when he came home.

The Larger downpipes take alot of the loudness out of the exhaust.

 

Just to point out that technically speaking wrapping the downpipe will increase lag. You want everything as hot as possible before turbo and as cool as possible after the turbo to decrease lag.

That being said the benefit of sheilding the TMIC from the heat offsets this added lag effect. Now, if you're setup with a FMIC or on a race car that is always moving I wouldn't suggest wrapping anything past the turbo.

If you wrap any part of your exhaust you need to be sure to use the recommended hi-temp sealant product to seal the installation.

 

By wrapping the downpipe you can lower your under the hood temps by 70%. by keeping the exhaust gases from cooling, the exhaust velocity can remain high. Imporving the scavenging effect.

For every 10 degree decrease in air intake tempature, you can expect hp gains of 2% on a turbo and supercharged car.

I was prolly heat soaking my engine bay and stuffing hot air in my short ram intake. but whatever happened the wrap deff solved the problem. All you need to get if you want to wrap your d/p is a roll of 2x50 Header Wrap at any perfoamance shop. I painted the wrap b/c is sometimes changes colors after the break in process.

cavy i have some snaps of the d/p ill see if i can dig them up for ya. and if you do decide to try this, ide be more that happy to come give ya a hand.