The other day I had received my new Renick catless downpipes, so I took the car down to Chequered Flag Automotive to let Chris and Shawn get those installed. While it was there, they spent lots of time tracking down a noise in the left front of the car that appeared after the first autocross. After checking and tightening everything on that side of the car, they disconnected the newly installed sway bar and methodically played with end links etc, The weird part is that the sound appears to be gone now but they never really found anything.
Each pipe has a resonator in place of the cat (4th image), and there is a H pipe (crossover pipe) that connect the two together. There are all kinds of extra bungs on the pipes in case you need to connect more sensors (wide band O2, etc).
I pick up the car in the morning, and when I get back home I have a new tune to install to better take advantage of the lower restriction in the exhaust. It should bump me up another 25 or or so (up to 525 rwhp?) and allow the turbo's to spool a little quicker. EDIT: New tune installed. The car seems to rev a little quicker and the throttle response seems to be a little sharper. And it sounds a WHOLE lot better. 🙂
Not sure what else I really want to do to this engine right now. I may go ahead and do the Renick cold air intake worth another 20 hp to bump it up to a total of about 540 rwhp? That should be plenty. The car is still under warranty so I don't want to do anywhere close to what's been done to the other car. I will get a Boostane tune which would bump things up again due to the higher octane (102 versus 93), to ~560-570 hp. At that point I'd be good for now. If I need more power in a straight line I'll hop in the other car. 😉 Saw a dyno of another ATS-V with the IDENTICAL setup as our red V and it was making 693 rwhp and 704 ft lbs of torque on E70. Not bad for a 3.6 liter V6. 🙂