car runs quicker without the exhaust hooked up..

[Stephen Johnson]

Well i figure you guys can help me out alot since u r so limited.. I have a 306 that has 1 3/4 longtube headers.. 3in collector goin to a 2.5in dr gas x-pipe.. goin to 2 chambered flowmasters with 2 1/4in tips.. my car has run a 12.08 at 112mph with the exhaust hooked up.. and 11.86 at 115 or 116mph.. i can't figure out what the deal is.. but it has done this more than once.. Does anybody have any ideas on what is goin on.. or what to do.. I need help bad guys..lol.. I hate to drop my exhaust to run open headers.. to get in the elevens.. plus all the ford races require u to have exhaust hooked up any ways.. thanx..

[david powell]

3in collector goin to a 2.5in dr gas x-pipe.. goin to 2 chambered flowmasters with 2 1/4in tips.. my car has run a 12.08 at 112mph with the exhaust hooked up.. and 11.86 at 115 or 116mph.. i can't figure out what the deal is

hell dude take a good look at your exhaust system:it start's off big and get's smaller as it exit's the car,that is the wrong way it needs to stay the same size out of the collector or get bigger as it exit's

[Stephen Johnson]

thanx for you real good advice.. very appreciative.. i know what to do now..