DCAWD.com

In my quest to keep the commuter REX as stock looking as possible I was thinking of gutting one of my stock down-pipes.

I've gutted an up-pipe before and it was difficult and time consuming. I hope to not to have to expend that much energy this time so I'm opening-up to the group for sugestions on the best way to accomplish the task.

My initial thoughts are rebar and hammer for most of it and follow-up with a grinding wheel and wire wheel for clean-up.

Any other (better) thoughts?

I will say, one of the advantages of going with a non-stock DP is that you eliminate that flat flange that can interfere with the workings of the wastegate. That being said, if someone is on a budget or (like in your case) wants as much of a stock look as possible, gutting it a great option.

Rebar and a small sledge hammer will work really well if you can get the rebar around the bend at the top or the bottom (maybe bend it a little?). I keep thinking of these things, but I have never tried it. You could also throw some propane in there, stand back 15ft, and light the sucker on fire

Also, it goes without saying, wear a good dust mask and gloves.

Sabre wrote:You could also throw some propane in there, stand back 15ft, and light the sucker on fire.

Does that really work? Does it really burn the cat out or does it just break down the material so it will fracture? How much propane and how long does it need to burn?

drwrx wrote:

Sabre wrote:You could also throw some propane in there, stand back 15ft, and light the sucker on fire.

Does that really work? Does it really burn the cat out or does it just break down the material so it will fracture? How much propane and how long does it need to burn?

i've never gutted a dp myself. i'm curious to learn about it though. i know sti up pipes can usually be had for a song. might be worth it versus the labor of gutting one. i could be wrong though... fire is always fun, right?

I'm not sure how cats break down. I tried to burn out my first up pipe with a propane torch and oxygen, but it just melted the cells down and made globby goops. I don't know if heating the substrate up really hot and then flowing unlit propane across would react with the catalyst and break it down.

I do know that after 4 years of water and methanol injection, my 2nd cat evacuated the premises entirely.

Could try putting the pipe on the grill and takin the garden sprayer to it every ten minutes. Maybe extreme thermal shock would help fracture things up a bit?

zaxrex wrote: I do know that after 4 years of water and methanol injection, my 2nd cat evacuated the premises entirely.

this made me

complacent wrote:i know sti up pipes can usually be had for a song.

Indeed, I have an 07 up-pipe ready for installation. $50

zaxrex wrote:I'm not sure how cats break down. I tried to burn out my first up pipe with a propane torch and oxygen, but it just melted the cells down and made globby goops.

That is exactly what i would expect.

zaxrex wrote:I do know that after 4 years of water and methanol injection, my 2nd cat evacuated the premises entirely.

You mentioned that at the last meet. I have to see that.

My only problem with baking it and then throwing water on it is that if you hit the metal, you could fracture the DP itself.

ZaK: I'm guessing that depends on the type of cat. I honestly have NO idea what kind of cat we have. Metal substrate? Ceramic? I think the propane would work well on a ceramic because of the pressure way cracking it, but I'm not so sure about the metal type.

nobody wants a cat it seems

drwrx wrote:

zaxrex wrote:I do know that after 4 years of water and methanol injection, my 2nd cat evacuated the premises entirely.

You mentioned that at the last meet. I have to see that.

Clean as a whistle.

Sabre wrote:ZaK: I'm guessing that depends on the type of cat. I honestly have NO idea what kind of cat we have. Metal substrate? Ceramic? I think the propane would work well on a ceramic because of the pressure way cracking it, but I'm not so sure about the metal type.

It is metal substrate, otherwise it would be $$$ to replace from the factory, as opposed to just $$.

Oops, in my head I saw up pipe. My bad.

zaxrex wrote:Clean as a whistle.

Get off of my screen and get onto my car!
(oh sure, like nobody here gets the Billy Ocean reference)

I spent some time looking over the dp closely and I think i'm going to pass on trying to gut that thing. There is no easy way to get a piece of rebar in there from either end (even bent). And trying to clean it out after most of it has been punched out will be next to impossible.

Zak, Is that a Subaru 2nd cat? It looks like a TXS?

Yeah, TXS.
Sorry, man. Wish it were stock.

if you wanna get a dirt cheap greddy http://forums.nasioc.com/forums/showthr ... ?t=2219396

^^^ That's a pretty good deal! Looks like the full turboback is for an 08... otherwise I would have bought it for the race car.

Darrin: You could always try to find a used Maddad downpipe. Looks stock and has a cat... meow!

Sabre wrote:You could always try to find a used Maddad downpipe. Looks stock and has a cat... meow!

Trying to find a used "shorty" down pipe is difficult. I have been looking for weeks. I ordered a Stromung shorty dp from Daddy's. Don't know when it will arrive as as I have not received a shipping confirmation yet.

If I don't hear anything by the end of the week I'm canceling the order and looking elsewhere.

It will be fun to see the gains we realize from tuning with it and all your other mods. Speaking of which, headed to ROMRaider forums now to ask about the automatic tranny...