Secondary Cat delete only?

[satinghostrider]

Heres mine with a cat delete and resonator delete w/ Supersprint X-pipe and ACS Race Mufflers.

[rod1]

Any rasp associated with deletion of the secondary cats? With regards to replacing the section where the secondary cats are located, would resonators be a better choice than a straight pipe considering performance and sound? The last thing I would want would be my car to drone and rasp.



Also, who makes good software for the secondary cat deletion and how does it affect warranty?


Thanks

[J08M3]

no software is necessary for secondary cat delete since o2 senosors are only on primary cats. Make sure to leave the resonators and you will have no drone or rasp sound. just straight pipe is all that's necessary as replacement since resonators already exist farther back from factory.

[rod1]

Yes, but it only makes sense to get new software which takes in account the new airflow.

[KINGLEH]

Can you post up pics from under the car... The 2nd cats seem to be oddly shaped and direct from end of them to the beginning of the X' part of the X pipe.. Ide like to see exactly where you cut. I will be doing this myself. Soon...

[J08M3]

For those who haven't seen it in my other thread. I recently just sold this to another member as I got bored again and went for a full new exhaust system including HFC for the primaries haha.

[rod1]

Any dyno's comparing the two?

[powertrip]

Originally Posted by J08M3

no software is necessary for secondary cat delete since o2 senosors are only on primary cats. Make sure to leave the resonators and you will have no drone or rasp sound. just straight pipe is all that's necessary as replacement since resonators already exist farther back from factory.

I deleted my 2nd cats AND resonators and there is ZERO drone. It's really not all that raspy either...only when the exhaust is cold and you rev the engine. Other than that it sounds more like a stock M5/M6.

[marcielago]

So this thread is useless right now. You almost convinced me of not getting a full exhaust. What exhaust did you get? Roughly how much louder is it right now?

[powertrip]

Originally Posted by marcielago

So this thread is useless right now. You almost convinced me of not getting a full exhaust. What exhaust did you get? Roughly how much louder is it right now?

I just bought the Active Autowerke exhaust and the Gintani is on order. I'm installing the AA tonight, so I should be able to provide some feedback tomorrow.

[J08M3]

Originally Posted by marcielago

So this thread is useless right now. You almost convinced me of not getting a full exhaust. What exhaust did you get? Roughly how much louder is it right now?

[J08M3]

Originally Posted by rod1

Any dyno's comparing the two?

I haven't been on a dyno yet with this car.... unfortunately

[Marvelous]

[SOCAL]

I deleted the secondary's but did it in a "stealthy" way.... I picked up an extra mid pipe section from another member and actually hollowed out the secondary cats and left the primaries intact. The whole setup looks 100% stock. I also did the OEM rear section mod as seen right heeeaw http://www.m3post.com/forums/showthread.php?t=352503

As far as sound, it got louder for sure, but the perfect amount louder... it turns heads now crusing around town everywhere. There is still no drone, a bit of rapsiness was picked up but I like raspiness... go figure... very happy with the secondary delete. For power gains, who knows, if you saw the pile of $hit I took out of the secondary cats to hollow them out you would definataly see they are a kink in the system. It suites my needs and pocket book well, looks OEM, fits OEM, and screams like a burning crackhead at WOT. I love.....

[dscarfon]

i am getting meisterschaft gt2 stainless steel rear section.... any thoughts if i should delete secondary cats... PLEASE HELP!!! i want alot of rumble, neibors to get mad... but not like a raspy tuner car