erik litchy Posted March 4, 2005 Share Posted March 4, 2005 i looked before the 2nd cat in my car and the exhaust narrows to 1.5" before the 2nd cat. why did they design it so? Link to comment Share on other sites More sharing options...
archemitis Posted March 4, 2005 Share Posted March 4, 2005 low end torque! that and they never thought that heat shield would rust away. so when it was new, it looked like it had some desent sized exhuast. Link to comment Share on other sites More sharing options...
erik litchy Posted March 4, 2005 Author Share Posted March 4, 2005 low end torque! that and they never thought that heat shield would rust away. so when it was new, it looked like it had some desent sized exhuast. heat sheild? you mean on the 2nd cat? its not rusty on my car. but like everyone says scavaging does not improve by making the exhaust smaller. Link to comment Share on other sites More sharing options...
erik litchy Posted March 13, 2005 Author Share Posted March 13, 2005 i was thinking of taking a tailpipe expander to the area. can anyone think of any reason I shouldnt? Link to comment Share on other sites More sharing options...
NorthWet Posted March 13, 2005 Share Posted March 13, 2005 I haven't looked at it, but I can't think of a good reason other than fitment issues. No exhaust "tuning" is effective after the first major obstruction to exhaust flow. Mufflers and cats attenuate any exhaust pressure pulses, so no further benefit can be derived by keeping the atmosphere side restrictive. Link to comment Share on other sites More sharing options...
erik litchy Posted March 17, 2005 Author Share Posted March 17, 2005 heres a visual aid Link to comment Share on other sites More sharing options...
All_talk Posted March 17, 2005 Share Posted March 17, 2005 I think the pipe ahead of that point is about the same size, so I don’t think there is much to be gained by expanding it at that point. If the pipe forward looks larger check to see if its double wall. My ’87 GL wagons is, looks big on the outside but its only about 1.5" inside the inner pipe. Its like that from the heads to the muffler and I’m sure its stock. I found it when I had a bad rattle in the mid pipe, I fixed it with a few spot welds from the outer to the inner along the pipe, I did the Y-pipe too. Gary Link to comment Share on other sites More sharing options...
MorganM Posted March 17, 2005 Share Posted March 17, 2005 I'd cut it off right before there and go with a straight custom cat-back exhuast Link to comment Share on other sites More sharing options...
fud24682000 Posted March 18, 2005 Share Posted March 18, 2005 '87 GL wagon,D/R: So Gary--the rattle on idle and during deceleration that I have been thinking is in the inside of the cat may be something else rattling? Sure hope so, cheapest new cat I can find is $180+. Ray Mac Link to comment Share on other sites More sharing options...
All_talk Posted March 18, 2005 Share Posted March 18, 2005 '87 GL wagon,D/R:So Gary--the rattle on idle and during deceleration that I have been thinking is in the inside of the cat may be something else rattling? Sure hope so, cheapest new cat I can find is $180+. Ray Mac My '87 had the same idle/decel rattle, I read some people fixed loose cat "bricks" by squeezing the can, I tried this with no success. So I pulled the mid pipe and found it was the inner pipe, so I cranked up the welder and burned through the outter to the inner in about dozen places, and not a sound since. Gary Link to comment Share on other sites More sharing options...
[ i ]nsane Posted March 20, 2005 Share Posted March 20, 2005 Ouch, I guess I'll be making a non-cat exhaust system.. thanks for the pic Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now