This is kind of old news but I'm bored and I just wrapped up my DEI header wrap project (bad joke, I know) so I thought I'd post pics.

I had to remove the starter's heat shield to fit my homemade 3" cat-pipe and that necessitated some heat wrap. Oh, and don't mind my lack of welding skill. Lot of first tries on there.

Replaced this:


With this:


And did this:

 

Nice job for first time effort. Hmmm, I've always wondered
about the collapse inner pipe. Is it due to thermal expansion,
heat cycle or just metal fatique. Is the collapse just before
the cat Dark & how far into the pipe ?

 

No complaints here, looks good.

 

I am wlling to wager one orange that the pipe will graze on the ground. Looks nice though!

 

J Chen - the stock cat-pipe is fine at the downpipe flange but you can see it begin to collapse shortly after that. I suppose I could cut the old pipe into 6" long sections and find out, but right now it's on display with the rest of my personal Hall of Shame. It's right next to the DSM turbo with a half inch of shaft play. Yes, a half inch.

NZ951 - it's honestly not that much lower than the cat used to hang down. It did rub very lightly once when I went over a rather steep incline but then again I rubbed the bat wing too; purely driver stupidity.

 

Holy crap! How common is it to collapse like that? And are there any symptoms or ways of checking without cutting into it? Mine only has 70k miles.

 

Mine only had 98k miles and evidently it's a common 944 turbo issue. My symptom was the inability to reach high boost; in fact, I couldn't hit over 10psi.

 

BTW, the stock cat, after all of this time, is a big freaking metal CLOG! Mine had about 160k on it, and you could barely see through it with a flash light. I didn't even bother to look at the pipe. No cat is SOOO much better! Nice job Dark.

 

I've heard of a silicone spray that you can use so the wrap doesn't soak up water....and it's heat resistant.. just don't get, even a tiny bit near the intake!!

looks nice

 

How much LOUDER is the car with the new exhaust setup?

 

Dash01 - I have a 3" cat-pipe, the stock cat-back, and it's barely louder than stock. A little more rumbly but besides that it's very very quiet.

 

So the collapse was before the cat?

 

todd - Correct. As far as I can tell the collapse is due to the use of multilayer piping and the only place such piping is used is in the front portion of the cat-pipe. I'm guessing the multiple layers have a dual purpose: to add strength and to act as a pseudo heat shield. The downpipe and cat-back use single layer pipe.

 

Correction Dark,
The turbine out section of the down pipe is
also 2 layers but with more spacing between
the outer & the inner tube. I discovered it when
I did my GT25 install. Funny thing was that the
inner pipe was welded only to the turbine flange
side. I think that pipe was installed to minimise
flow reversion.

 

I noticed that same thing with the cat-pipe. It only seemed tacked at the front (downpipe side).