I've got a somewhat odd situation here - I searched but couldn't come up with anybody having the same problem.

I just bought a new(to me) axle back exhaust and put it on the car, when I fired it up it was smoking quite a bit, mostly just normal exhaust color with a bit of black at high rpms. I went for a quick drive (5 minutes) to test it out and see how it sounds and I just noticed as I was pulling up my driveway the engine temp was in the red, like top of the needle. I have no clue how long it was up there, I've never had any problems with overheating in this car before.

Basically what I'm wondering is if a higher flowing exhaust can make that big of a difference to engine temps, or if this is purely coincidental and my fan just happened to cut out at the exact time i swapped mufflers..
I also have a big cold air intake and header. the engine in question is a z6. I shouldn't need any fuel management for just i/h/e right?


any help would be appreciated.

thanks