nothing235

Hi,
I have a mostly stock '87 N/A. I recently bought a used Bonez High Flow Cat(Owner said it had less than 10k miles on it, and it looked to be in pretty good condition.) This cat has the exact same dimensions as the stock cat. It should suffice for emissions by itself so I want to remove the pre-cats. I need to replace them with either a downpipe from the stock exhaust manifold to the new cat, or? a new manifold pipe directly to the cat?... Anybody know where I can get one of these 2 pieces?
Thanks,
Ryan

socalrotor

iTrader: (1)

well seing that your in CAli home of the hater smog shiznit the best thing to do ,IMO, is take off the first and second cat and gut them till there hollow. That way you will always pass the Visual/Test only smog. BTW the first cat is empty 90% of the time, so chances are you won't have to mess with it. Now all your left with is the second one to mess with. I have had 3 Fc's and all of them had NOTHING in the first cat. Hope this helps.

nothing235

I was considering gutting the pre-cats...Visual emissions should pass either way, I don't think a pre-cat is required for visual, just a cat. (At least thats what is listed to 'check visually' on the checkoff sheet they gave me after passing.)

However, from what I hear gutting pre-cats creates a lot of turbulence and would not be as beneficial as a straight pipe. Does anyone know if this turbulence effect is negligible or not?

Sadly neither my parts car, nor my car's 1st precat is empty so I may end up having to gut them both.

Jager

iTrader: (10)

Buy my Bonez supeflo, its everything from the exhaust manifold to the last stock cat, where a high flow cat sits.

$150 shipped.

socalrotor

iTrader: (1)

good answer.....buy another cat

I also live in cali and I Failed "test only" due to not haven't all three cats. I got screwed I guess. I haven't heard about the terbulance issue, but I haven't ever search it either. Also, won't it be pretty loud with 1 cat on a straight pipe? I think the first 2 cats also quiet it down a bit.

Jager

iTrader: (10)

It was rumbly, not too high pitched, as my cars site right now (******* LOUD). With the stock exhaust manifold its considerably quiet then a car with headers.

I just mentions it to him since it might be cheaper then going without custom, plus, its a good system.

37FC3S

The Bonez super flow is $315, the race pipe is $150. I have a Bonez super flow and passed a smog test at a test only station. Racing Beat has down pipes for NAs that might work but I would call them to confirm that it would work on your car.

nothing235

I called racing beat, they said they have no N/A downpipe to stock Cat setup... oh well. For now I'll just gut the CATs. Maybe I'll add another post tomorrow titled gutted cats turbulence asking about this turblence thingy. Thanks for the info and help.