[YBnormal07]

Waiting list?

Hey all,
I'm thinking of disconnecting the exhaust line just in front of the 2nd cat (or resonator box...looks the same these days) just in front of the center differential. I'd like to see if there are any performance gains from the reduced backpressure. Everything I understand about a turbo says that the great the d/p across the turbine, the faster it spools the compressor wheel, therefor quicker response.

My question is with less backpressure, I should get faster flow through upstream cat. Will this affect the upstream cat at all? I know it won't hurt exhaust temps as the sensor is upstream of the disconnect point. Just concerned that I might fry my cat. Don't know enough about them to be sure. I'm heading out in about an hour so any response would be appreciated.

Assuming I can disconnect with no issues, I do know to drive the car for a bit prior to realizing any gains, as the ecu will need to adjust.

Regards,
Scott

 

[bi11y]

there wont be any emission issues removing that cat?

 

[YBnormal07]

oops...guess I should clarify. This wouldn't be permanent. Just a track day test to see if I can gain a tenth or so in the quarter or a couple of tenths on a road track.

I actually already disonnected it once just to see how easy it is and to hear the sound. Surprisingly not as loud as some of the kids cars you hear running around. Takes about 5 minutes, 10 total if you include jacking the car up to access it (with proper supports of course).

Anyway...any response on issues with the cat? This about the only concern I can think of (for short duration running that is).

Scott

 

[YBnormal07]

OK...since I didn't get any negative responces I gave it a shot. Took 3 passes in about 85 degree heat, so not excessively hot. Best time was my first run...a 13.1 @ 103. A new personal best for me!!

Won 50$ bucks on a side bet on my 3rd run, against an Evo. Kids were betting he would take me. 13.28 against his 13.9. cha-ching!

As for the sound, it is different, especially once the turbo is in full spin...sounds like a jet going down the road. Weird.

Timeslips to be posted later.

Scott