I'm thinking about getting cut outs installed when I have my SFCs welded in my car since the shop I am going to can do just about anything with cars. One thing I am concerned with is the shape of cut outs, as I understand it the are Y shaped and direct the exhaust flow to the cat or just out into the open so wouldn't this hurt flow when they are closed? I have dual cats so this means I need 2 cut outs correct? Lastly, I want to install headers too but I was going to get the cut out first since SFCs are my top priority so I'd just do them at the same time but with no headers will the cut outs hurt my back pressure enough to matter?

 

First off back pressure=bad...you never want it. The closer to zero...the better. Second, no shop will install a cutout before the cat and if you find one then you won't pass emissions cuz those people won't like it. You should put your cutout after your "Y" pipe. Also, I would get the headers and a new Y pipe after the SFCs...then get a good cat-back and install a cutout into that.

 

1. Get the cutouts, they're awesome to run around with. Also it money allows get you a couple of McCord Power Plates so you can open and close them with a push of the button.

2. From what I have read, the power loss is so small, that it shouldn't even be a concern.

3. If you are going to do it right, I would get 2.

4. When you have time, do a search for backpressure. If I understand it correctly (and I'm sure this will be argued), back pressure is bad no matter how you look at it. What you need to be worrying about is scavaging. Just get a good set of headers and again, if money allows, get a free flowing exhaust, and you shouldn't have to worry about. As for now, I can't imagine running cutouts with the manifolds is going to hurt anything.

5. Where were you planning on putting the cutouts? I know in most cases, you'd want it before the cat, but when I did that, I scraped over every speed bump, and couldn't even get into my driveway without scraping. I ended up moving it to the intermediate pipe, right before the axle.

EDIT: I can't type fast enough. ksrammstein beat me too it.

 

I probably should've mentioned I have dynomax dual catback 3" exhaust already on the car SFCs are my main concern right now since I have a t-top car but I figure if someone is gonna be welding down there some cutouts would be nice. I definitly want the cut outs before the cat as I'm not running any mufflers right now. As for emissions there is no visual just the sniffer so if I have the cut outs closed I should be ok right?