ATR EXHAUST Installation question/Problem

[2500avalanche]

I just got a 3" cat back ATR exhaust, new, never installed. My question is the prior owner took the original cat out, and put a 3" test pipe in its place (see pic below), So, I want to run a cat (high flow - see pic below), do I cut the part of the pipe that goes down to the original 2.5" and weld the cat directly to the pipe, and then have the cat welded to the test pipe? I am curious if that would be the correct way to connect everything...
PS: See the nice crushed part of the exhaust... It is roughly only 1" in width. Now, I wonder why my truck never could get any boost!

 

[90pgt]

Re: ATR EXHAUST Installation question/Problem

I think that would be the best way, too cut off the flange that goes to the stock cat and weld on a new flange for the new cat so it can be removed later

 

[2500avalanche]

Re: ATR EXHAUST Installation question/Problem

I think that would be the best way, too cut off the flange that goes to the stock cat and weld on a new flange for the new cat so it can be removed later

I understand you thought, but I was going to just have the cat welded to the piece, and forgo the flange.

 

[Gnocide]

Re: ATR EXHAUST Installation question/Problem

dont run the cat- not necessary

use a cut out instead- also use clamps dont weld anything

 

[2500avalanche]

Re: ATR EXHAUST Installation question/Problem

I do have a "fake" cat. I can use.
I worry about spiking...
So, the 3" test is the same diameter as the fake cat. So I can use that , what type of clamp should I use for them? I could cut the 2.5" off myself and clamp that directly to the fake cat (they are the same diameter too

 

[2500avalanche]

Re: ATR EXHAUST Installation question/Problem

Also, on the top pic, there is a bracket that the exhaust is welded to (right above the crushed part) it is attached to the cross member. I dont see it in the pics from ATR

 

[Gnocide]

Re: ATR EXHAUST Installation question/Problem

with stock turbo & wastegate setup you may spike-
you will overboost in OD with the stock system because of wastegate hole in turbo being too small.

i use 3 inch stainless clamps that came with kit
3 in steel will also work - remember this kit was designed to bolt on and unbolt for easy removal.

sounds like you'll need a reducer from 3 to 2.5 for your stock down pipe
there is no welding at all on the kit- just uses stock hangers(minus the cat).

 

[2500avalanche]

Re: ATR EXHAUST Installation question/Problem

I dont think I will need any reducer.to a 2.5". The issue is that there is that the ATR is 3" to a 2.5" (which connects to the cat). I don't have a cat, just a test pipe (which is already 3") So, what I was going to do cut the 2.5" section off the atr pipe (that is supposed to connect to the Cat, use a butt-style clamp (all the pipes are the same size) to connect the ATR piece to a fake cat, and the same butt style clamp to connect to the existing 3" test pipe. Does that make sense?

with stock turbo & wastegate setup you may spike-
you will overboost in OD with the stock system because of wastegate hole in turbo being too small.

i use 3 inch stainless clamps that came with kit
3 in steel will also work - remember this kit was designed to bolt on and unbolt for easy removal.

sounds like you'll need a reducer from 3 to 2.5 for your stock down pipe
there is no welding at all on the kit- just uses stock hangers(minus the cat).

 

[blue83z]

Re: ATR EXHAUST Installation question/Problem

would you be willing to make a copy of the ATR paperwork for me? would be nice to have in my folder of stuff.

 

[2500avalanche]

Re: ATR EXHAUST Installation question/Problem

would you be willing to make a copy of the ATR paperwork for me? would be nice to have in my folder of stuff.

Will do! Give me your email address

 

[0966Sy]

If you do not have emissions tests that require the cat then don't use one. If you do then you need to get a cat on there. The bracket that is welded to your current exhaust is the support for the cat/down pipe. You want to use a factory style cat that will slip over the stock down pipe and be supported in the back with the bracket. You ATR cat back if not modified should bolt up to the stock cat. Keeping it all bolt on will help in the future upgrading down pipe for a larger turbo.

If you don't need the cat, don't fear the boost spikes. Look into getting a forge wastegate, it will control it without spikes. I run a 20g with stock down pipe and ATR cat back exhaust with a bolt on SS test pipe made by RPM.

 

[2500avalanche]

Re: ATR EXHAUST Installation question/Problem

If you do not have emissions tests that require the cat then don't use one. If you do then you need to get a cat on there. The bracket that is welded to your current exhaust is the support for the cat/down pipe. You want to use a factory style cat that will slip over the stock down pipe and be supported in the back with the bracket. You ATR cat back if not modified should bolt up to the stock cat. Keeping it all bolt on will help in the future upgrading down pipe for a larger turbo.

If you don't need the cat, don't fear the boost spikes. Look into getting a forge wastegate, it will control it without spikes. I run a 20g with stock down pipe and ATR cat back exhaust with a bolt on SS test pipe made by RPM.

So, I need a factory style cat? Are they on every s10 or specific to the ty?
The test pipe is welded to the DP... I know, I didn't install it. it was this way when I bought it

 

[Gnocide]

Re: ATR EXHAUST Installation question/Problem

got classic plates in pa?

definitely dont need a cat
under 5000 miles a year= no cat

 

[0966Sy]

You don't "need" a stock cat, it would just be an easier bolt on affair. Now that you mentioned the pipe being welded at the down pipe makes me think first that you need to decide wether or not you can cut/grind the weld off to save the down pipe to go bolt on. If you can't save it then maybe your best bet is to have a universal cat welded on.

The cats are not syty specific, there are two different size/styles found in most 1st gen 4.3 s series trucks

 

[2500avalanche]

Re: ATR EXHAUST Installation question/Problem

You don't "need" a stock cat, it would just be an easier bolt on affair. Now that you mentioned the pipe being welded at the down pipe makes me think first that you need to decide wether or not you can cut/grind the weld off to save the down pipe to go bolt on. If you can't save it then maybe your best bet is to have a universal cat welded on.

The cats are not syty specific, there are two different size/styles found in most 1st gen 4.3 s series trucks

What I am going to do is to have the magnaflow direct fit cat welded to the DP (stock 2.5 ") and then attach the cat back to that. My truck is stock, and I worry about spikes (don't want to go boom!).
I think that is the best bet. That way, I can install the exhaust correctly, and the truck will be basically back to stock. the pipe is around 129$, and direct fit. I was under the truck earlier, and sincethey will need to cut the 3" pipe off, there is still the straight part of the DP left in which they can attach teh cat OR weld a small pipe to the DP and weld the cat to the 2.5 pipe.
I figure it isn't a worry. Things happen, just don't want to do it in a hurry, and screw it up, and have to redo it. (I waited 3 years so far to get to this point, I can wait another 2 weeks!)

 

[Aeroking]

Re: ATR EXHAUST Installation question/Problem

PLEASE, do not cut any of the ATR piping.

And unless you modify the exhaust housing or go to an external wastegate, you will spike without a cat.

 

[2500avalanche]

Re: ATR EXHAUST Installation question/Problem

PLEASE, do not cut any of the ATR piping.

And unless you modify the exhaust housing or go to an external wastegate, you will spike without a cat.

Thanks man, I am not cutting it. I will be buying a direct fit Cat so that they will bolt together, like they are supposed to.

 

[Gnocide]

Re: ATR EXHAUST Installation question/Problem

PLEASE, do not cut any of the ATR piping.

And unless you modify the exhaust housing or go to an external wastegate, you will spike without a cat.

open up the turbo hole for waste-gate -dump the cat -use cut out sounds great!

 

[Vaders Sy]

Re: ATR EXHAUST Installation question/Problem

Can you post pics of the final installation? Is that the kit RPM sells? I wanted to see what the exhaust tip looked like for my new Sy.