Replace the CAT on 2.5" Exhaust
10-05-2010, 04:14 PM
#1
Rennlist Member
Thread Starter
Replace the CAT on 2.5" Exhaust
I have a similiar question that was brought up in the "WTB 3" exhaust" thread, and I did not want to hijack that thread so. . .
I have been looking for a way to switch out the cat in my original exhaust, but it seems as though the only way to get the desired results is to just go ahead and get the full 3" exhaust with the sport cats.
Anyone have any other cost effective ideas?
I have been looking for a way to switch out the cat in my original exhaust, but it seems as though the only way to get the desired results is to just go ahead and get the full 3" exhaust with the sport cats.
Anyone have any other cost effective ideas?
10-05-2010, 04:36 PM
#2
Three Wheelin'
Buy whatever cat you want online, take it to a muffler shop and have them weld it up. All told you'd be out of pocket ~$100 for the cat (or more, if you really want to splurge), and <$100 to have it installed, depending on the shop.
Or for $500: http://www.944online.com/cgi-bin/ASI...skukey_1000432
Or for $500: http://www.944online.com/cgi-bin/ASI...skukey_1000432
10-05-2010, 05:12 PM
#3
Rennlist Member
Thread Starter
Unfortunately, I live in CA (see sig), and it is not that simple. I have not found a muffler shop yet that will "weld it up". That's why I was wondering if any company has a kit or something, or if anyone in the Bay Area knows of a shop that is willing to "weld it up"?
Anyone?
Anyone?
10-05-2010, 07:13 PM
#5
Three Wheelin'
Magnaflow makes Cali-Specific Cats. On Summit they have: http://www.summitracing.com/parts/MPE-36106/
I did a quick cross reference from Magnaflow's site and that is the one recommended for the 944 Turbo.
Maybe if you tell them it's Cali-Approved they'll be more inclined to help? Worse comes to worse you go to a not-so-good neighborhood and find a muffler shop there.
I did a quick cross reference from Magnaflow's site and that is the one recommended for the 944 Turbo.
Maybe if you tell them it's Cali-Approved they'll be more inclined to help? Worse comes to worse you go to a not-so-good neighborhood and find a muffler shop there.
10-06-2010, 10:21 PM
#6
I also live in calif and I just removed mine yesterday. I keep 2 seprate pipe sections, One has the cat welded in place and the other has the cat removed, Takes abour 1 hr to switch them over. 9 bolts total and you are done.
10-07-2010, 01:26 PM
#7
Drive-by provocation guy
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Before I went with the 3" exhaust I just cut the cat out with a saw zaw and clamped in its place a piece of 2.5" straight pipe from the parts store.
Took about 30 min and cost about $7 and made a major difference.
Took about 30 min and cost about $7 and made a major difference.
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10-07-2010, 03:26 PM
#8
Rennlist Member
Thread Starter
I checked out the one on 944online and their is no info. on it. So I asked them some basic stuff, i.e. cell count, diameter, direct-replacement, and there response was "That's a good question. I will ask the manufacturer and get back to you."
that was Monday. . .
I am looking for a permanent solution, not hack, saw, bolt, unbolt, switch every 2 years, and was hoping someone had something and/or knows someone, etc. with knowledge of CA stringent smog testing.
I geuss the LR is the only viable example because I have gone to "poorer neighborhoods" and the muffler shops are scared to work on a porsche.
that was Monday. . .
I am looking for a permanent solution, not hack, saw, bolt, unbolt, switch every 2 years, and was hoping someone had something and/or knows someone, etc. with knowledge of CA stringent smog testing.
I geuss the LR is the only viable example because I have gone to "poorer neighborhoods" and the muffler shops are scared to work on a porsche.
10-07-2010, 10:18 PM
#10
Rennlist Junkie Forever
Here's what you want to do...
Buy the Bursch 2.5" test pipe. Buy the cat you want, take both to the muffler shop and have the cat cut in to the test pipe and welded up. Then take the piece home and swap it out with your stock piece.
Likewise, if you don't want to run a cat, just run the Bursch 2.5" test pipe alone.
What you DO NOT want to do is to cut out the stock cat and replace it with a straight pipe. What most people do not understand is that the factory pipe is double walled. And in the area where the factory pipe transitions from vertical to horizontal, the inner part of the pipe is crushed down considerably. You cannot see this from the outside.
That said, the performance benefit is partially from the cat removal, but mainly from eliminating the crushed section of factory exhaust.
The Bursch test pipe is a direct bolt in and costs about $250 new.
And I can tell you that an aftermarket boost controller, a Tial wastegate, and the Bursch test pipe will make the turbos in these cars hit 2x harder than they do now. It's great money spent.
TonyG
Buy the Bursch 2.5" test pipe. Buy the cat you want, take both to the muffler shop and have the cat cut in to the test pipe and welded up. Then take the piece home and swap it out with your stock piece.
Likewise, if you don't want to run a cat, just run the Bursch 2.5" test pipe alone.
What you DO NOT want to do is to cut out the stock cat and replace it with a straight pipe. What most people do not understand is that the factory pipe is double walled. And in the area where the factory pipe transitions from vertical to horizontal, the inner part of the pipe is crushed down considerably. You cannot see this from the outside.
That said, the performance benefit is partially from the cat removal, but mainly from eliminating the crushed section of factory exhaust.
The Bursch test pipe is a direct bolt in and costs about $250 new.
And I can tell you that an aftermarket boost controller, a Tial wastegate, and the Bursch test pipe will make the turbos in these cars hit 2x harder than they do now. It's great money spent.
TonyG
10-07-2010, 11:38 PM
#11
Burning Brakes
Here's what you want to do...
Buy the Bursch 2.5" test pipe. Buy the cat you want, take both to the muffler shop and have the cat cut in to the test pipe and welded up. Then take the piece home and swap it out with your stock piece.
Likewise, if you don't want to run a cat, just run the Bursch 2.5" test pipe alone.
What you DO NOT want to do is to cut out the stock cat and replace it with a straight pipe. What most people do not understand is that the factory pipe is double walled. And in the area where the factory pipe transitions from vertical to horizontal, the inner part of the pipe is crushed down considerably. You cannot see this from the outside.
That said, the performance benefit is partially from the cat removal, but mainly from eliminating the crushed section of factory exhaust.
The Bursch test pipe is a direct bolt in and costs about $250 new.
And I can tell you that an aftermarket boost controller, a Tial wastegate, and the Bursch test pipe will make the turbos in these cars hit 2x harder than they do now. It's great money spent.
TonyG
Buy the Bursch 2.5" test pipe. Buy the cat you want, take both to the muffler shop and have the cat cut in to the test pipe and welded up. Then take the piece home and swap it out with your stock piece.
Likewise, if you don't want to run a cat, just run the Bursch 2.5" test pipe alone.
What you DO NOT want to do is to cut out the stock cat and replace it with a straight pipe. What most people do not understand is that the factory pipe is double walled. And in the area where the factory pipe transitions from vertical to horizontal, the inner part of the pipe is crushed down considerably. You cannot see this from the outside.
That said, the performance benefit is partially from the cat removal, but mainly from eliminating the crushed section of factory exhaust.
The Bursch test pipe is a direct bolt in and costs about $250 new.
And I can tell you that an aftermarket boost controller, a Tial wastegate, and the Bursch test pipe will make the turbos in these cars hit 2x harder than they do now. It's great money spent.
TonyG
This sounds like the best solution to the OP's probably. And mine.
10-08-2010, 11:45 AM
#12
Rennlist Junkie Forever
Everything I read one of your posts, I learn something new. At what power levels will the 2.5'' test pipe become restrictive? It seems like everyone here says the $600 3'' exhaust is necessary to get rid of stock exhaust restrictions...
This sounds like the best solution to the OP's probably. And mine.
This sounds like the best solution to the OP's probably. And mine.
Somewhere in the 350RWHP - 360RWHP ish...
TonyG
10-08-2010, 12:25 PM
#13
Rennlist Member
Tony's right on all counts. As for welding in a new cat, you can review the CARB rules and refer your muffler shop to the list of approved converters for "Pre-OBDII" cars published by the State of California and found here:
http://www.arb.ca.gov/msprog/aftermk...xemptcat09.pdf
And see this link for the related requirements:
http://www.arb.ca.gov/msprog/aftermk...ftermktcat.htm
In short, you have plenty of options. Just go to Summit's online catalog and you will see a number of weld-in converters that are CA-legal for pre-obdii cars like the 86 951.
Bursch test pipes are pretty well made and fit nicely. Probably best to install it in place, then have the muffler shop weld it the cat in place, so that you know it's the right length, fit, etc. Or, get yourself a mig welder.
http://www.arb.ca.gov/msprog/aftermk...xemptcat09.pdf
And see this link for the related requirements:
http://www.arb.ca.gov/msprog/aftermk...ftermktcat.htm
In short, you have plenty of options. Just go to Summit's online catalog and you will see a number of weld-in converters that are CA-legal for pre-obdii cars like the 86 951.
Bursch test pipes are pretty well made and fit nicely. Probably best to install it in place, then have the muffler shop weld it the cat in place, so that you know it's the right length, fit, etc. Or, get yourself a mig welder.
10-08-2010, 12:36 PM
#14
Hey Man
Rennlist Member
Rennlist Member
If you go the Bursch route you can have V-bands welded on so you can remove the cat for 'off-road' use and swap in a straight pipe. I have an new Bursch TP sitting here I plan to have welded up once I get to that point.