American Power

I will be doing probably 2 HPDE's per month. The car is a weekend warrior. No trips to Starbucks with the Mrs. in the Z.

I have built the car for occasional street use, friday night get together or Sunday morning blast, but mostly track fun. I will be running....

Forged LS7 with 12.0-1 Compression ratio.
Ported heads with cam, springs, TI retainers, Morel Lifters, chromoly push rods. Ported T-body and Intake. LPE CAI. AR headers.
LG coilovers
Hoosiers
T1 Sways
Caravaggio seats w/ harness bar and 5 Pt harness
Stoptechs
LG Spindle ducts
Exedy Clutch/ Lightened flywheel

I have AR headers 1 7/8 with High flow cats. To make the most out of this engine do I need to go catless. I know with the X pipe it will be a little louder and I will probably smell a little gas. That aside...

How much power am I robbing from my engine, and those cats are going to be under a lot of heat and pressure..

What should I do? Even if the HP gain is small, Perhaps the engine will run better during those 20 minute HPDE...

Your thoughts... Anyone gone from cats to no cats and see any advantage at the track?

wtknght1

We were allowed to remove the cats this past year in T1 and it was definitely louder...and we did get more power...about 5HP as I recall. The key though is the tuning. Just taking the cats off won't get you more power. In fact, it will probably be worse and your engine will run a lot richer (flames out the back). If you take them off, you must get the engine retuned to benefit from the extra exhaust flow.

If you're not going to do that, don't waste your time.

95jersey

I did exactly this on my C6Z and noticed a slight seat of the pants improvement, but did not DYNO the improvement. But more importantly, the engine now rev's faster and has better throttle response, and now I can actually hear the motor when I blip the throttle. At HPDE's I could not even hear my own car, which I actually use the sound of the motor more than the RPM guage itself. I I also use my car for 95% track, and didn't want to drop the $1200 on a cat back for just an improvement in sound.

With the mods listed above, honestly, the last thing you need to worry about is 10 more HP.

American Power

I'm not worried about gaining 10 hp so much. If I go this route I will have it tuned for no cats. I just think the car will run better at the track, and it's an 80% track car.

What the hell, I'll try it. If I don't like it I'll switch it back to the Freeflow cats.

AU N EGL

Does that other 20% time need to be concerned about emissions and annual inspection? If not take those cats out.

If it does, Random Tech Makes high flow cats and X-pipe. Tuning the car for these high flow cats, helps with the emissions inspection plus give more HP then stock cats. Not like open and no cats, but much better then stock.

Good Luck