With several things.

1. Performance. I actually measured the performance after I gutted the cat. I did 3K-6K sweep on the tach with a stop watch averaged the three runs before and after. After gutting the cat the car was about 1 second quicker consistently. Conditions were the same...within the hour of the same day.

2. Backpressure being needed. That's a big fat no no with turbo cars. You need NO backpressure after the turbo. In fact no exhaust at all is ideal when talking turbo. But since we can't do that we compromise.

I have plenty of automotive engineers who are friends that agree, plus actual dyno charts showing the car with a 2.5" full exhaust, down to a 2.5" downpipe, down to open turbo. Guess what? It gained *9* hp at the same boost by going from open downpipe to open turbo right off the turbine housing. The curve looked the same with no loss anywhere.

3. That screen inside the cat. I just used a big pry-bar and scraped it out and pounded it to the hole, got some channel locks and gave a good tug. It was tough but a good gutteral grunt and it was out. :-)

I know I disagree with a lot on the board, but I'm a pisser for empiracal data and have been building turbo cars and performance cars in general for over 16 years. I'm not trying to piss anyone off, just present facts to help you get the most of of your car. :-)

posted by 24.18.134...

• Gutting a SPG cat, BuHuSPG, Wed, 26 Dec 2001 23:37:14
  • So whats the verdict, BuHuSPG, Thu, 27 Dec 2001 23:35:00
    • Cat Guts, SteveW, Fri, 28 Dec 2001 10:43:49
    • the turbo is the backpressure!, dave n, Fri, 28 Dec 2001 08:59:52
    • Re: So whats the verdict, Jay Hassinger, Fri, 28 Dec 2001 07:45:10
  • Re: Gutting a SPG cat, SDP, Thu, 27 Dec 2001 12:36:29
    • Sorry but I have to disagree, Jay Hassinger, Fri, 28 Dec 2001 07:55:13 <-- Viewing This Message
    • Great thread, now what kind of cat is the best...., lms, Thu, 27 Dec 2001 17:48:20
      • Search- high flow cat, but why 3" down? (long), SDP, Thu, 27 Dec 2001 20:11:21
  • remove it with the downpipe, dave n, Thu, 27 Dec 2001 06:43:01
    • Re: remove it with the downpipe, Johann F, Thu, 27 Dec 2001 08:01:00
      • So by your logic then, Jay Hassinger, Thu, 27 Dec 2001 08:47:30
        • Re: So by your logic then, Johann F, Thu, 27 Dec 2001 09:50:11
          • Re: So by your logic then, Jay Hassinger, Thu, 27 Dec 2001 10:50:50
            • no theory here., dave n, Thu, 27 Dec 2001 16:10:07
            • Re: So by your logic then, Johann F, Thu, 27 Dec 2001 12:50:33
              • Well some final thoughts, Jay Hassinger, Fri, 28 Dec 2001 07:58:52
                • Re: Well some final thoughts, Johann F, Fri, 28 Dec 2001 08:27:46
                  • Re: Well some final thoughts, Justin VanAbrahams , Fri, 28 Dec 2001 11:57:46
              • Agree- and some, SDP, Thu, 27 Dec 2001 20:28:51
              • Dunno which FI system you're referring to... but,, bazil burns, Thu, 27 Dec 2001 15:26:46
                • Re: Dunno which FI system you're referring to... but,, Justin VanAbrahams , Fri, 28 Dec 2001 11:35:45
  • Re: Gutting a SPG cat, chrisx, Thu, 27 Dec 2001 04:09:34
  • yes but just a few considerations, Quinn S. Kurz, Thu, 27 Dec 2001 01:51:26

No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.

• Prev by Date: Re: So whats the verdict, Jay Hassinger, Fri, 28 Dec 2001 07:45:10
• Next by Date: Well some final thoughts, Jay Hassinger, Fri, 28 Dec 2001 07:58:52
• Main Performance Bulletin Board

StateOfNine.com

SaabClub.com

Jak Stoll Performance

M Car Covers

Ad Available

The content on this site may not be republished without permission. Copyright © 1988-2024 - The Saab Network - saabnet.com.
For usage guidelines, see the Mission & Privacy Notice.
[Contact | Site Map | Saabnet.com on Facebook | Saabnet.com on Twitter | Shop Amazon via TSN | Site Donations]

Random Saabnet.com Member Gallery Photos (Click Image)