Chuck,I did some dyno and track comparos on the cutout.
The car had a 274" S2, ATR exhaust, no cat, Pitbull muffs.
Chassis dyno: Found 3-5 RWHP more open.
Track time, almost nil. I was looking at 1/4mi mph.
142+ to 142 flat. Same day, cool down time, etc. Some minor weather changes were involved.
Plug readings were so close I couldn't see a difference.
Great information, Thanks for sharing!!!
Was the ATR exhaust 2.5inch or 3inch?