Is it senseless to add headers before replacing the stock cats?

 

no, exhaust can come in any order

i theenk?

 

Nah, it's not a a "bad idea". As far as flow restriction, the cats are probably the worst; replacing those first might get you the most noticeable initial gains. However, there's nothing wrong with doing the headers first if you want. If you've got them and know someone who can install them for you... go for it. But down the road, you'll definitely want to address at least the cats and the stock y-pipe, as those are very restrictive areas. (You can do a whole cat-back exhaust if you want, but replacing the stock y-pipe with a good aftermarket piece usually frees up as much flow as a full aftermarket exhaust.)

 

HF cats will only lessen the restriction on the engine...as will the headers. Our dynos have shown that in the vicinity of +20hp is possible with just the headers on a stock 350...so go ahead and indulge in a set of headers...but remember the test pipes are an economic thing that you will want to install at the same time because you are working on the same exact part of the car.

Victor D.
www.nexusindustry.com

 

I'm installing just the crawford headers now... will modify the exhaust lil later...

 

Well I've already got the Borla TD so my assumption is that the headers should be a welcome addition to my set up. Since I am gonna be replacing the cats in the semi-near future anyway, I guess my biggest hangup involves having to pay twice for the install. Once for the headers, and again later for the cats. If I can be patient, I may wait until I have both and get them installed at the same time. I am getting in on the sweetheart of a deal that Jason from TopSpeed is making on the GB for the headers and then in a month or two I am gonna get some High Flow Cats from the Crawford boys. All this modding...it's becoming a sickness

 

Im currently running DC Ceramic Headers, Stock Cats, NISMO Exhaust and it keeps me very happy

 

I wouldn't worry too much about that. The cats are a super easy install. If you have a buddy who can work on cars or who works at a shop, he'll probably do your cats for a case of beer or something. That's how I got mine installed.

 

Good to know. I have a good friend who is pretty knowledgeable and has access to a lift. He just replaced his clutch a couple of weekends ago on his Mustang so cats should be pretty easy for him.

 

Taking labor into consideration, the cats will cost you under $90 at most exhaust shops. The headers are a much harder install and should be done by a pro. I had my DC Sports installed for $450.

 

Yeah, the header install is a serious job. Definitely a pro job. The cats are pretty easy, though. They are under the car, so if you can put it up on a lift it shouldn't take long at all. My buddy did mine in about half an hour at his shop. The only thing that can slow you down is if the bolts are really stuck. They sometimes get that way on the super hot exhaust parts like headers and cats.

 

I am counting on getting the top speed headers, and crawford cats. What should be next after these two mods?

 

ok so which mod has better hp and torque increase? headers or hi flow cats?

 

Headers for sure, but you are paying much more for it and to install.