cat...

Gary Derian gderian at cybergate.net
Thu Aug 20 12:11:24 GMT 1998


A real air pump won't use any more power for the air it compresses than the
Vortech does.  Does your air bypass actually pump much air into the exhaust?
Check the pressures.  You should be able to run lean during cruise without
driveability problems.  Isn't that what EFI is for?
Gary Derian <gderian at cybergate.net>



>While we are on the subject of cat's, I have a sort of EFI related question
>about cat's more especially on that rotten egg smell.
>
>First thing's first a description of what we are all up against.
>
>1984 RX-7 13B with a Vortech supercharger, SDS EFI 2 primary and 2
>secondary injectors of 50lb/h ea.
>
>Exhaust temp at idle is 750Deg. F WOT is 1475Deg. F the thermocouple is
>about 2.5" from the exhaust ports; the exhaust is a custom-made 2.5' pipe
>with a hi-flow 3 way cat and a Borla muffler.
>
>I am bypassing a small quantity of compressed air from my Vortech to the
>air tube in the cat, but I am getting a very bade rotten egg small from my
>exhaust I am leaning out my AF mixture but now I am at a point where I am
>afraid to lean out more and kill my engine and also I get a bit of stumble
>if I do lean it out more, the AFR monitor that I use is one of those cheap
>ones, It reads a bit riche.
>
>What is a guy supposed to do run a car that smell's like rotten egg's or
>pull the cat off, or get a reel air pump and loose a few HP?
>
>Alain Marchildon
>
>
>




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