pre-cats.
Drifting
Joined: Dec 2000
Posts: 1,733
Likes: 0
From: Sarasota FL
Re: pre-cats. (devilfish)
I think you gain a little. On mine the 2 1/2" Y-pipe and main cat combined with the elimination of the pre-cats made a SOTP difference (what ever the butt dyno is worth).
Edit: sound and performance difference.
[Modified by DON M, 7:46 AM 3/26/2002]
Edit: sound and performance difference.
[Modified by DON M, 7:46 AM 3/26/2002]
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: pre-cats. (devilfish)
You may see a small gain.
But look at those waffled bends in the stock front Y! The real gains come from installing a 2 1/2" mandrel bent front Y w/o pre-cats.
But look at those waffled bends in the stock front Y! The real gains come from installing a 2 1/2" mandrel bent front Y w/o pre-cats.
Thread Starter
Melting Slicks
Joined: Oct 2000
Posts: 3,010
Likes: 1
From: Sweden/Stockholm
Re: pre-cats. (65Z01)
you say 2 1/2" mandrel bent front Y w/o pre-cats. Can a muffler shop do this to me? And what is 2 1/2" in the european metric system? And what is "mandrel bent"?
Regards
Regards
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: pre-cats. (devilfish)
So 2 1/2" is about 64mm.
I had a local specialty shop custom build a 2 1/2" SS front Y-pipe for me. They mandrel bent and welded the tubing into a very clean unit that just bolted up to my hi-flow cat and the stock headers.
Mandrel bent means all bends are done on a mandrel to give a smooth contour, without the waffeling you see in the factory pipes at the bends. This waffeling effectively reduces the cross-section and so reduces flow. If you do a crude measurement on some of the stock bends you'll see that the cross-section may be less than half that in a straight section.
I had a local specialty shop custom build a 2 1/2" SS front Y-pipe for me. They mandrel bent and welded the tubing into a very clean unit that just bolted up to my hi-flow cat and the stock headers.
Mandrel bent means all bends are done on a mandrel to give a smooth contour, without the waffeling you see in the factory pipes at the bends. This waffeling effectively reduces the cross-section and so reduces flow. If you do a crude measurement on some of the stock bends you'll see that the cross-section may be less than half that in a straight section.
