Seems that the 3 in X pipe with welded UltraFlos slowed my GS up about a tenth over open exhaust this past weekend. (10.35 128 vs 10.25 129 that I predicted) When I tow it to the track I'll have to pull the whole thing off to really test it. I did notice that the idle was smoother....(900 rpm in gear) I'm starting to think that the 3 in is too small and it is hindering the breathing of the Stage 2 heads. Should I lean it out with the x-pipe? Bruce
I'd like to see back to back runs on the same day...... I've never run my car w/o exhaust,But no x-pipe either.
I have a complete 3.5 inch exhaust under my car with a 3.5 inch X pipe and I didnt ever compare it to anything but my car seems to love the X pipe. The wifes GS went 2 tenths faster and 2 mph with stock manifolds and an X pipe addition!!
OK, soon I wiil remove the whole thing at the track and see. I didn't expect to go faster I thought it would run the same as open or so I heard. I was running 12 in extentions on the headers when open so maybe that was the hot ticket. Bruce
