I recently had an O/R H pipe and dumps put on. I am running Flowmaster Series 40's. The car sounds really great but I have now gotten a backfire when shifting during a race. I did not have this before the install. I got under the car and found where the dumps are not completely welded to the mufflers at the top. I have been told by a couple of people that the dumps not being completely welded are causing the backfire. I have also been told that Flows will tend to backfire when dumps are put on. Is it that I am sucking cold air in during those high RPM shifts? These are the mods I have so that you have a better picture of what I am running. Thanks for any help.
1997 Mustang GT 4.6L 2V
C&L 80MM MAF w/True Flow inlet pipe
K&N Air Filter with fender relocation
MAC 70MM TB
Superchip with mail order tune
MAC O/R H pipe w/dumps and Flowmaster Series 40's
4.10 gears
Granatelli Solid Upper and Lower Control arms
B&M Ripper Shifter
Parts I have that are going on this week:
PI Cams
Aluminum U/D Pullies
Steeda full length SFC's
Battery relocation kit
1997 Mustang GT 4.6L 2V
C&L 80MM MAF w/True Flow inlet pipe
K&N Air Filter with fender relocation
MAC 70MM TB
Superchip with mail order tune
MAC O/R H pipe w/dumps and Flowmaster Series 40's
4.10 gears
Granatelli Solid Upper and Lower Control arms
B&M Ripper Shifter
Parts I have that are going on this week:
PI Cams
Aluminum U/D Pullies
Steeda full length SFC's
Battery relocation kit