Thread: Header Wraps

FWIW, I pulled my set-up off in the fall to get at my alternator. I had my downpipe wrapped with thermotec but the manifold was not wrapped. The downpipe looked like brand new when i pulled the heat wrap off and the manifold was showing some signs of rust starting.

Needless to say the manifold was sandblasted and resprayed with BBQ paint and wrapped the same as the downpipe was.

YOU should invest is some brakes!!

this is very tempting for me now that i hear all these stories of it working well. i have no A/c and my header has not been installed yet. how much did every one use? should i use 1 inch wide? or 2 inch wide? i want it to look really nice if im going to do it. will i be OK with 50 feet of 1 inch wide?

ill be doing my secondary in 2inch wide and not worried about it looking super uber awsome.

I am pretty sure I used 50ft of 1 inch wide on the primaries, but it has been a while. It also depends on how you wrap them. I pulled mine really tight and overlapped a lot because I didn't want hose clamps visible on top like the pic above. I liked the wrap a lot too, cooled things down. I could pretty much hold onto the headers after an hour of driving. couldn't find any pics of it, makes me sad it looked real clean and I spent about 2 hours wrapping it.

2" will probably be too thick to deal with on primaries. This is why I got 50' of 1" black (for looks ).

I will post up when I get it and when I install it

I have always used the 2" without problems. A helpful tip, soak the wrap in water for a few minutes before using it. It will keep fiberglass dust from flying around, and make the wrap much easier to use.

i agree soaking the wrap is a good idea

Hahaha, here goes, you guys are going to hate me for this...

Being the geek I am I decided to find out for myself how much exhaust gas temperature affects its velocity. So, I set up a sheet of calculations to calculate the gas velocity based on the density as a function of temperature. A few things to note about this are that I used the density values for air because the densities at different temperatures for exhaust gas are not readily available and my theory is that air will still give an OK approximation. Also, I did not include any flow energy losses like friction.

Anyways, I am pretty sure I did this correctly, and the results I found I have put on a chart to show you all. Don't quote this as being 100% correct but based on my assumptions and such I think it works out like this:



It looks like the velocity really does increase with the exhaust gas temperature, but not by a huge amount. Although you can't argue with having a little extra flow, to me it seems like the bigger advantage to wrapping your headers is cooling your engine bay. Now I want to do it too lol.

BTW: This chart is for an SR20DE with 2 inch headers

Yah, would have loved to have figured out how to do it w/o the clamps, but at least it doesn't move. Most definitely NOT a waste of bux - it's a CHEAP solution to radically reducing underhood temps - lots of expensive pieces in there that will be LOT happier and likely last a LOT longer. Don't know about performance gain; wasn't the reason I did it. I think also I used about 50' of the 1" stuff. 2" would be a royal pita to use around all those bends.

Should have added - on the clamps: I've crewed for sports racers for over 3 decades (early days, McLarens, recently, Lolas) - you learn a few things doing that - 1) keep it simple; 2) make it strong; 3) keep it neat; 4) if you have the time, make it pretty. (Pretty usually means more neat.) Why? If it doesn't break, you don't have to fix it.

^Not on the daily, the ceramic pads on stock calipers do just fine for me ..............My other car is getting the big brakes.......,but if you have some spare NX calipers laying around at your place. You can put them on the my car as a surprise if you want to




^Nice chart