So here are some clips of the hahn exhaust and catless downpipe, both with the cutout closed and open:

http://www.youtube.com/watch?v=iw2ODRztqkg

The camera guy kept hitting the "record" button as I drove by (stopping the recording) but you can get an idea of how it sounds.

At idle, sounds like crap when open and when closed creates a huge exhaust leak right past it. WOT I think its over the "rice" line... Im going to pull out the electric valve and bolt the plate back on permanently.

However, with the cutout open and cruising on the highway, I noticed an almost 150 degree lower temperature difference...

 

A lot quieter then I though it would be.

 

Beleive me, its not quiet by any means. When you are in the car, the stereo has to be up at 3/4 volume before you can even begin to hear it.

Remember those videos were made with my friend standing off the side of the road, ZOOMED IN. In the first run of the cutout open, you can hear the camera distort, and I'm still a good 75 feet away. If you want to get attention, this is one way of doing it, but it will get the attention of people you dont want (aka cops).


However, thanks to the turbo, its not nearly as loud as it would be on a N/A car

 

150 degrees colder than what, and where is this temperture measured?

 

COT temp

 

the 08+ (dont know about earlier years) have a stock EGT sensor - I have no idea where it is physically, but its before the downpipe. I was monitoring using my interceptors.

BTW for anyone that doesn't know - COT is Cat Over Temp. The stock ECU uses this sensor to enrich the fuel mixture if the temps go above a set range, thereby lowering EGTs to a safer range.

 

There isnt actually a sensor, it's a calculation done inside the ecu.

 

I thought it worked through the 2nd o2 sensor?