Hi-Flo cat vs. testpipe?

[Jeff240sx]

Right now I have the factory 2" Inlet/Outlet dummy cat, and am going to swap it with a 3" resonated test pipe or a 3" hi-flo cat. I really want my 3" turbo-back exhaust, with no bottlenecks. Now I'm wondering what will be best for my three issues, first bieng most important:
1) Power. Which makes more?
2) Sound. Anything should sound better than that box, but what will quiet things more? And if a non-resonated test pipe is the answer, so be it.
3) Other benefits. You tell me this :).
The testpipe will probably be a Project Silvia piece, while the hi-flo cat will be an ebay item *shrug*
Let me know opinions, so I can finish the underside of my car.
-Jeff

[240Stilo]

My guess is you probabaly already know what you want but need people to back you up. With power being the #1 issue go with the project silvia test pipe.

[speeddreamz]

My guess is you probabaly already know what you want but need people to back you up. With power being the #1 issue go with the project silvia test pipe.

-Power, hardly any backpressure = faster turbo spools = also better high end.
-It sounds meaner.... not quieter than anything that has a cat though. So , it will be louder even tho its resonated
-shoot flames...which is cool untill a cop sees it

[Jeff240sx]

I really don't know what I want. My car is damn loud, and I'd prefer not to shoot flames, since with flames comes backfires. I'd give up 3% horsepower for less flames and quietness. I think either will give more power than the dummy cat that's in place. If a hi-flo cat will increase spool drastically, or severly limit horsepower, then I won't get it. If a resonated test pipe is louder than non-resonated, I'd want that.
Looking for help!
-Jeff

[sykikchimp]

a 3" Hi-flow cat will quieten the car just a little, and sacrifice a very small amount of hp. They are still straight through after all. What make them "High-flow" is generally the design of the openings into the catalyst. regular cats typically have louvers that stick out into the exhaust flow. High flow cats typically just have holes. They take longer to heat up, but work just as well as a normal cat when up to temp.

Be green! use a cat!

[Gladman]

i doubt a high flow cat would sacrifice any hp... if anyone it would add low end power that would outweigh any higher end loses..... a 3" highflow cat isnt goin to be very restrictive at all.

[WilloW]

I don't know about the power gain, but a nonresonated testpipe will be just as loud as a resonated one. I've been told that the nonresonated will flow better than the resonated, but it will sound like crap. I've owned both before and I can't tell the different with the power gain, but I can tell how shitty the nonresonated pipe sounds.

[240Stilo]

Supposedly there have been issues with high flow cats also so you might want to look into that. Personally, I tried to search for issues with it and came up with nothing. Who knows...maybe I didn't search hard enough.

[INeedNewTires]

i would go with the Hi-Flow cat from Catco, sold at www.summitracing.com its cheap (46 bucks) flows great, works great, and keeps things as legal as possible. i just bought one myself, and although im not turbo, it helped quite a bit. you probably wont give up any power (that would matter) and the sound would be a bit quiteter (which is good!)