Electric cutout/dump pipe

[mdog]

So, the mustang is sold, and by April I'll be actively searching for an Evo. I tryed to do some searching on my future ? with mixed results, but I'll throw this out there and see what the consensus is. I will be using Evoscan or Mitsulogger for my datalogging, and Ecu Flash to make any fine tuning adjustments after a good base flash from either Al or Jestr. I'm really liking the idea of using a QTP?(I think) electric cutout/dump pipe so I can go from stock to ready to rock with the flip of a switch on the exhaust. Now, keep in mind I'm using EcuFlash and I don't really want to be swapping tunes back and forth for every time I open the cutout. My thought is to have a tune for the cutout, and then just drive regularly with the exhaust closed for the majority of the time. Obviously it's a compromise, but as long as MPG and drivability isn't effected greatly it doesn't bother me. Anyone see a huge problem that I"m over looking with this? My other concern is throwig a cell for the rear 02's when I open the pipe since the aft cat 02's are pretty much by-passed when the cutout is open. Is there a way to "turn off" the rear 02's? Or does the cell only get thrown when you eliminate the cat and it reads to high of a voltage, but doesn't get thrown if the value is below a certain threshold? If nothing else it would freak folks out at the track here when I pulled up next to them in a quiet little 4 banger then all of a sudden in less then 5 seconds the thing goes to sounding like a possessed monster when you open the cutout and get on the 2-step.

[Fourdoor]

This is the exact setup I have on my wifes WRX. I did what you are talking about, had the car tuned on the dyno with the cutout open, and then just shut the cutout to run normally. It has very little affect on the wide band O2 sensor when the cutout is closed vs cutout open.

Even with the cutout wide open, some of the exhaust stream will be flowing out through the stock cat and cat back system, so you should not have any problems with the O2 sensor throwing a check engine light.

I know that QTP has a few people running a prototype downpipe built specificly for the EVO that has a 3" cutout built in just like the one I am using on my wifes car, but I don't know if they have them up for sale yet on their web page.... you may have to give them a call to find out.

Keith

[mdog]

Excellent news! Not only does that nicely maintain the stockish sleeper look, but from what I'm gathering it doesn't cause problems with drivability when you're cruising around with it closed, but on the open tune. If the pipe is $500 though for the pipe/electric cutout combo I may go super cheap and just get a 3" brand x downpipe and buy the electric cutout seperately and cut out a section of the downpipe so I can weld in the cutout. I've got a few months, but if what I buy has a stock exhaust I think this is the way I'd like to go.