Formula934

iTrader: (4)

Ive been running catless on my procharged trans am now for a little over a year through a long tube headered/magnaflow 3" exhaust. The car makes between 650-700rwhp. Im looking to add a single cat in the I pipe to reduce the rasp and clean up the smell of the exhaust.

The 3 options im thinking of are

1. Kooks green cat ge-90140
2. MBS high flow 50 cell cat
3. Vibrant performance cat 7830

Anyone have experience with a high horsepower car and a single cat?

ddnspider

iTrader: (26)

Rasp can be handled with a small bullet muffler or resonator....and exhaust smell is due to your tune. I wouldn't add a cat.

Formula934

iTrader: (4)

I have a 24" power stick muffler sitting in the garage i was thinking to throw on there but still looking at options. While the car isnt that bad with fumes, its enough to notice. My car is wideband tuned and im targeting an AFR of about 14.2 on idle. Slightly lower then stoich to account for the 10% ethanol in the 93 pump gas. What are your thoughts on the tune?

ddnspider

iTrader: (26)

I target higher AFR and will also, depending on cam overlap, run open loop idle. The 10% difference in E never really made a difference in my tuning (up to ~750whp on 93 only) and cars idled/smelled better.

truckdoug

iTrader: (25)

solution: switch to e85

Formula934

iTrader: (4)

Would be a viable option but they dont offer it in the northeast or its hard to come by. Im forced to use 93/meth.

NitrOmm

iTrader: (1)

I had the same issue. Years of smell & years of reputable tuners trying to help (at least three with no such luck).
I simply lived with it. It got to the point that my wife wouldn't get in the car (of course I told her I would miss her ).
Ultimately I was able to get a hold of a set of Kooks greens & I gave it a shot. NO SMELL. Happy as a pig in ****.

My wife still wont get in the car ... something about going sideways in second/third gear. Apparently that's frowned upon in her world.

Note: I suffered no power loss BUT I have a TD system with two cats. Pushing all that power through a single pipe would leave me to believe you will lose some power. Yes it will reduce rasp but if that is the main concern there are plenty other ways to get it done as mentioned above.

Formula934

iTrader: (4)

Can you elaborate on the TD system you have? What brand i should say and where did you put the cats? That may be a viable option for me.

9outofs10

Where in the northeast are you? I'm near Albany and we have a few stations near me that sell it.

gametech

iTrader: (1)

Any exhaust fuel smell means you will burn up a cat. The unburned fuel will light off in the catalytic converter and melt it. Either clean up the tune or live with it. That being said, you will note that no factory engines make high horsepower through a single cat. Many of the N/A ones use 4 cats. This is mostly due to emissions requirements, but still...

Formula934

iTrader: (4)

Point taken. It seems the consensus is to live without the cats or maybe run dual cats off the y pipe. I really was curious if anyone had a single 50 cell cat up to the task.

Formula934

iTrader: (4)

Im in the central mass area. Theres only one station near me and its about 20 miles away, on the mass pike. Not alot of options for E85 around here to be honest