I am looking at getting the borla cat back system. it has teh cutout after the cats to bypas the muffler. I know people have sail that you should always put the cutouts before the cats on the headers but if you have dual cats that will the restriction from that be negligible. How will it effect the power out put and the sound of my exhaust system. I currently have stock exhaust but i do plan to get the cat back system and also two highflow cats from Magnaflow or similar and some coated slp headers W/ AIR.

Thanks for the help guys.

Raptere

1991 Camaro Z-28
5.7L TPI dual cat
Bone Stock (So Far)

 

I've got an electric cut-out on my 91 Z28....located after the cats in the 3 inch Intermediate pipe. Both of my cats are removed.....I hope you like the sound of NASCARS...because.....when mine is all the way open....that's what it sounds like.....it's really raw....and VERY VERY loud....I had my stereo on 20....and it even drowns it out......but..it's cool...because..by the flip of a switch.....I can have it to just Flowmaster volume...

 

What if you still have two cats there?

 

I've got the one cat setup on my car, so I would only need one cut-out. How much does one of these cost? What brands are out there? Also, I live in CA, so I am strongly assuming having this will be an automatic fail at smog inspection, am I right? -89IRO

 

you can get the cut outs at summit or jegs. the whole point of them is there is a plate with the plate on all of the exhaust goes through the entyre system (Fully Legal) Only when you want extra power in lets say a race you can take off the plate and insted of the exhaustgoing through the muffler and the cats depending where you put it does it become illeagl because it is basicly then a strait pipe.

 

you can get the cut outs at summit or jegs. the whole point of them is there is a plate with the plate on all of the exhaust goes through the entyre system (Fully Legal) Only when you want extra power in lets say a race you can take off the plate and insted of the exhaustgoing through the muffler and the cats depending where you put it does it become illeagl because it is basicly then a strait pipe.



I know having it closed would be, technically, legal, but when you have to get a visual smog inspection, I don't think this will work. Anybody else? -89IRO

 

Here in VA a cutout will not pass if installed before the cat (as it should be), even if it is not electric. Anything after the cat is fair game though.

 

I had the Borla on my 96 Z28. I didnt really notice any more power with it open, but the sound was AWESOME! If you were going to get a cutout I would not have spent the money on the borla. And two cats flow much better than one.

Brian

 

My cutout is right after the dual cats, where they join together. It works just fine for me there, but I've never had it dynoed to see the difference.

 

They say that the exhaust isn't as loud if you're running cat(s), so if you installed the cut-out after the cat(s) it wouldn't be "open headers" but it would still be very loud, right? I will go on the so cal board to see if this is legal. -89IRO

 

You wouldn't believe how much quieter it will be with a cat than without... Nothing like open headers at all. If you have free flow cats it might be louder than than with the stockers, but if you're gonna have cats there isn't that much to gain from a cutout behind them besides a few more db's.

Later,
Harry