LS2 exhaust downpipe with no converter...
06-17-2006, 10:42 PM
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LS2 exhaust downpipe with no converter... I'm putting a 2006 Corvette LS2 (58x reluctor) in a '55 Chevy without the smog equipment. The stock downpipe has a converter in it. Anyone know of a source that does the downpipe without a converter?
06-23-2006, 06:56 AM
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You are probably not going to find one since that would be illegal! Anyway I needed to make some down pipes for an LS7 going in an old Corvette and needed to do the same. The factory pipe includes the converter so it is crazy priced. But the gasket is about $15! I ordered the gasket and had a machine shop make me two flanges from 3/8" mild steel and welded the pipe to this. They were $150 for four - if you had an LS7 I could make you a deal. I made a funnel shaped collecter but I do not think it is required.
06-23-2006, 07:12 AM
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For the LS2 just order up a set of long tube LS1 headers for the old box (oops 55 shoe box). I think hooker made a set.
Or you could look at the Shorty headers and mid pipes for the LS1/LS2 GTO's as they should easily fit inside the engine bay of a 55 chevy.
Oh and there are Catless mid pipes for the Ls2 GTO, SLP I think.
Or you can just take a piece of 2 1/2" tube and have it mandrel bent.
Or you could look at the Shorty headers and mid pipes for the LS1/LS2 GTO's as they should easily fit inside the engine bay of a 55 chevy.
Oh and there are Catless mid pipes for the Ls2 GTO, SLP I think.
Or you can just take a piece of 2 1/2" tube and have it mandrel bent.
07-14-2006, 03:30 PM
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Down pipe flange and gasket Since the factory cat and pipe assembly is designed to bolt directly to the LS2 exhaust manifold, GM does not offer a flange that would allow you to run a simple 2.5" or 3" downpipe. I found some interesting flange candidates at Road Race Engineering in Calif. They stock some 2 bolt flanges that can be slightly modified to fit the 4" plus Chevy bolt/stud pattern on the LS2 manifold.
The flanges they sell are flat and do not have the machined recess that the factory gasket uses to seat the sealing ring. It may work that a flat gasket is OK or even that the factory gasket will seal when tightened up againt a flat mating surface of these flanges. Onward. Good luck. Mac
The flanges they sell are flat and do not have the machined recess that the factory gasket uses to seat the sealing ring. It may work that a flat gasket is OK or even that the factory gasket will seal when tightened up againt a flat mating surface of these flanges. Onward. Good luck. Mac
07-16-2006, 10:48 AM
#6
On my Vette conversion I cut the pipes in front of the cats and weleded some aluminized steel pipe on. Yes, there is a material mismatch... but it welded up and is holding fine. Even my H2 is holding fine with my bullet mufflers in place of cats. Just cut the offending cat out and weld in straight pipe. It will work fine.
