Two Cats in the Y

I've got 3" exhaust, no cats, with two vibrant resonators and Avo Wagon mufflers. Its too loud but I don't want less power. I want more. Going to hit 500hp next summer. I am wondering if putting a high flow cat into each side of the Y pipe would have the effect of lowering sound, helping with emissions, and keeping restriction down. I know that a high flow cat has little effect on 300hp but definitely has an affect at 350hp and up. I'm thinking if I divide the exhaust flow between two high flow cats that instead of all of it through one that it would solve all the problems without having to go the route of an exhaust cut out.

 

Let me know your thoughts.

 

Cheers

You always want more power .

You always want more power .

 

Eh.... I have been sitting on a 7163 (with quick spool!) for a few months now. Just waiting for money for the tune and modified exhaust.

 

Also I got beat by a golf last week with my 6758.

Golf R? Modified?

Golf R? Modified?

 

Debadged, quieter then my ride.

Sneaky guy.

 

 

 

K back on topic.

I don't know the answer to your original question . Hopefully, someone will chime in.

Don't cats work on temperature, I thought they had to be near the hot exhaust ?

 

You might need to find a performance muffler to add in the mid pipe.

Rally cars tend to run their cats right at the exhaust tips. It won’t be as efficient back there from the emissions prospective though because it’ll take a while for the cats to heat up enough to start the reaction. Once they start the conversion is exothermic, so they should keep themselves active at anything above idle.

i doubt they'll get hot enough unless you heat wrap the entire exhaust up to where the cats are.

Try wrapping the pipes all the way back. I wrapped mine all the way to the Y pipe and it quieted the cabin down quite a bit.

I think it would be fine. If you've played with different restrictions in an exhaust system, you'd see that any point of restriction is where the heat builds up. So if you put the cat(s) in the midpipe, the heat would sit right in front of them, and they're heat enough to do their job. Especially if you use an aftermarket, hi-flow cat. They usually only work at startup, and the egts of a Subaru turbo motor are out of range of most cats, so they still smell. (Subaru egts are in the ~1400 range, while most cars are in the ~1100 - 1200 degree range). So the distance from the turbo would actually work in their favor. And if you got (2x) 3" hi-flow cats, I'd imagine they are meant for larger motors, which typically run lower egts. I'd say go for it! I'm probably going to do something similar with an aftermarket cat in the downpipe, and a 100 cell in place of the resonator.