Stebro test pipe installation question | FerrariChat

Stebro test pipe installation question

Discussion in 'Technical Q&A' started by ctnbop, Nov 22, 2005.

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  1. ctnbop

    ctnbop Rookie

    Oct 3, 2004
    10
    San Jose, CA
    Full Name:
    Canh Nguyen
    #1 ctnbop, Nov 22, 2005
    I noticed that the Stebro test pipe is about 1 cm longer than the cat that I removed from my car ('88 328). I really had to muscle it in. It eventually went in, but now the muffler is shifted to the left so the muffler spring mounts are skewed (a lot) and now the exhaust tips aren't centered in the muffler grill. This can't be right. Can those of you with Stebro test pipes give some input? Looks like my options are to call Stebro, take it to a local shop to have it cut and welded, or look for exhaust gaskets that are thinner.
     
  2. CliffBeer

    CliffBeer Formula 3

    Apr 3, 2005
    2,198
    Seattle, Washington
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    Cliff
    #2 CliffBeer, Nov 22, 2005
    I assume you have the single 3" cat rather than the twin cats. I also replaced the single 3" cat with a Stebro test pipe on my '88 3.2 - seemed to be the right length to me to be honest. The problem I had with the Stebro test pipe is that the outlet end of the test pipe does not have an ID sleave liner for the compressable exhaust gasket so that when you tighten down on the three sprung exhaust bolts the gasket collapses in on itself.

    Anyway, Dan at Stebro will likely work with you here to make sure you have a good fit - it may take him some time to actually do anything (repair/mod your current pipe or produce a replacement of appropriate length) however so be prepared to wait.
     
  3. ctnbop

    ctnbop Rookie

    Oct 3, 2004
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    San Jose, CA
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    Canh Nguyen
    #3 ctnbop, Nov 23, 2005
    Yes, it's the single cat. The length of the test pipe is the same as the total length of the cat (including the inner sleeve you refer to), but the flared end of the cat outlet ends about 1 cm short of the sleeve, and that's where the extra length is. Didn't think about the gasket collapsing without the sleeve, but it makes sense. It still seals okay?
     
  4. 285ferrari

    285ferrari Two Time F1 World Champ
    Sponsor

    Sep 11, 2004
    20,847
    Southern Md
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    Robbie
    #4 285ferrari, Nov 23, 2005
    I have the same problem with a test pipe from Stebro. The first one I got also did not have a fitting for the exhaust temp sensor. The second one had the fitting but is also a bit to long and makes my pipes sit to the left a tad and not exactly centered. I am having a custom muffler made and will compensate for that with the new muffler design....
     
  5. CliffBeer

    CliffBeer Formula 3

    Apr 3, 2005
    2,198
    Seattle, Washington
    Full Name:
    Cliff
    #5 CliffBeer, Nov 24, 2005
    ctnbop, mine seals OK now - because I fabbed up a sleave for the gasket. I went through a couple of gaskets before I figured out that I really needed to add a sleave to avoid the gasket falling in on itself when tightening the sprung exhaust bolts. The length seemed to be OK for me when installed but I have a Mondial so perhaps it is less obvious if it is a centimeter or two off in either direction. Like the other fchatter's comments here, I had to also weld on a nut and a short drilled/hollow bolt (and drill a hole in the pipe) for the overtemp sensor to thread in properly. The thread for this is a little unique at 1mm rather than 1.25 as it more common in this dimension. Probably not the end of the world if you don't install the overtemp sensor as you can assume temperatures will have come down substantially by way of replacing the cat with a straight pipe. Good luck!
     

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