93 GT Mustang Mufflers and Drive Shaft clearance issues

[93gtmustang]

Is there anyone on here running a Ford Racing aluminum drive shaft with a Flowmaster Exhaust? I want to know what kind of clearance you have between the driveshaft and mufflers. The exhaust that came with my car (fabricated , welded up with flowmaster mufflers) has about 1/4" clearance if that, and the driveshaft is pretty beat up from occassionally rubbing on the mufflers and driveshaft loop, from hard launch's at the track.

I'm getting a new alum. driveshaft and a loop with better clearance than the Ford Racing one that I have.

I have BBK shorties.

I've been looking at going with a BBK off road H-pipe, and Flowmaster cat back American Thunder,or Pypes?, Magnaflow?

I don't really want to spend alot, Flowmaster seems the best price for a full exhaust.

I would really like to go with the Mac Pro Dumps. But are they legal for inspection?

This car is street legal only because I dont have a trailer set up yet. The car is street driven only a 1/2 hr to the track and back.



Thanks for all the help



---------------------------------------------------------------

1993 GT Mustang / Ford Racing GT-40 Crate Motor B-303 Cam / Tremec T-5Z / 4.30 Gears / Detroit Locker / Moser 31 Spline Axles/ Subframe Connectors / BMR Upper and Lower Control Arms / Lakewood Adjustable Drag Shocks/



Best ¼ Mile Time – 13.18 @ 104mph

 

[Onefine88]

I have the FRPP Aluminum DS and Flowmaster exhaust on both my GT verts.

No driveshaft to exhaust clearance issues on either car.

Good Luck

 

[Mustang5L5]

I have the alum driveshaft and American thunder cat back....no issues at all

 

[jrichker]

I had a similar problem on the 89 GT I had. The mufflers had the bolt up joint that coupled them to the H pipe. If I was not very careful about how I twisted the mufflers, it would either rattle against the frame where the exhaust pipe went over the axle or rub against the driveshaft.

The trick is to jack up the car and put jackstands under each corner, but not on the rear axle. Then place the jack under the center of the rear axle and jack it up and down. This places the car in a similar position to what it is like while driving. Now observe the clearance between driveshaft and mufflers as the axle goes up and down. Loosen the muffler to H pipe joint bolts and twist the mufflers to change the clearance. At some point you will find a spot that provides maximum clearance between mufflers and driveshaft, but does not rattle against the frame. When you find it, tighten up the muffler to H pipe joint bolts and start the car to make sure that there are no rattles and rubbing. Run the rear axle up and down to check it out and then let it down off the jackstands.

 

[93gtmustang]

I had a similar problem on the 89 GT I had. The mufflers had the bolt up joint that coupled them to the H pipe. If I was not very careful about how I twisted the mufflers, it would either rattle against the frame where the exhaust pipe went over the axle or rub against the driveshaft.

The trick is to jack up the car and put jackstands under each corner, but not on the rear axle. Then place the jack under the center of the rear axle and jack it up and down. This places the car in a similar position to what it is like while driving. Now observe the clearance between driveshaft and mufflers as the axle goes up and down. Loosen the muffler to H pipe joint bolts and twist the mufflers to change the clearance. At some point you will find a spot that provides maximum clearance between mufflers and driveshaft, but does not rattle against the frame. When you find it, tighten up the muffler to H pipe joint bolts and start the car to make sure that there are no rattles and rubbing. Run the rear axle up and down to check it out and then let it down off the jackstands.

Thanks for the tip on setting the clearance.
There are no joints to loosen, this exhaust is welded at all points.
I think I'm going with the Flowmaster American Thunder cat back, then I can adjust.
Thanks for all the help,

 

[93gtmustang]

Are Mac Dumps street legal, will they pass inspection?

 

[88blowngt]

Is there anyone on here running a Ford Racing aluminum drive shaft with a Flowmaster Exhaust? I want to know what kind of clearance you have between the driveshaft and mufflers. The exhaust that came with my car (fabricated , welded up with flowmaster mufflers) has about 1/4" clearance if that, and the driveshaft is pretty beat up from occassionally rubbing on the mufflers and driveshaft loop, from hard launch's at the track.

I'm getting a new alum. driveshaft and a loop with better clearance than the Ford Racing one that I have.

I have BBK shorties.

I've been looking at going with a BBK off road H-pipe, and Flowmaster cat back American Thunder,or Pypes?, Magnaflow?

I don't really want to spend alot, Flowmaster seems the best price for a full exhaust.

I would really like to go with the Mac Pro Dumps. But are they legal for inspection?

This car is street legal only because I dont have a trailer set up yet. The car is street driven only a 1/2 hr to the track and back.



Thanks for all the help



---------------------------------------------------------------

1993 GT Mustang / Ford Racing GT-40 Crate Motor B-303 Cam / Tremec T-5Z / 4.30 Gears / Detroit Locker / Moser 31 Spline Axles/ Subframe Connectors / BMR Upper and Lower Control Arms / Lakewood Adjustable Drag Shocks/



Best ¼ Mile Time – 13.18 @ 104mph

Not to run off topic but what RPM are you crossing the traps at? And what's your 60 foot?

 

[93gtmustang]

Not to run off topic but what RPM are you crossing the traps at? And what's your 60 foot?

60' is 17.76-1.85 depending track conditions

traps about 5800 rpms, i'm shift at 5600 rpms and the shift light comes on before the finish line