FMU and Supercharger Pulley Question

NitroNixon · 05-14-2003, 08:08 AM

Do I need a FMU if I don't have a supercharger installed on my car? I'm asking because, I recently bought a 87 Mustang the came with a FMU already installed and it has an extra rib in front of the crank pulley, which looks like it was meant to run the belt for the supercharger that was once installed. Should I remove the FMU? It seems like my car is running rich, very rich. I get a lot of smoke from my pipes when I pull off from a light.

As far as the crank pulley, does anyone think that I need to replace it with a regular crank pulley, or even a underdrive crank pulley? Am I losing power for having this extra set of ribs in front on my serpentine belt?

Thanks for any replies.

302 LX Eric · 05-14-2003, 08:22 AM

No, you don't need the FMU. The FMU should only be working under boosted conditions anyways, so I don't think it's even doing anything for you. I would just stick an adjustable FPR on there and set it factory pressure (about 39psi) and be done with it.

E

NitroNixon · 05-14-2003, 08:55 AM

Thanks for the reply, I get a adj. regulator then, so should I leave the FMU in the car then?

Stang_Crazy · 05-14-2003, 08:06 PM

No, you don't need the FMU anymore. Just grab an adj. FP regulator and ditch the FMU.

05-14-2003, 08:08 AM	#1
NitroNixon Registered Member Join Date: Mar 2002 Location: DC Posts: 129	FMU and Supercharger Pulley Question Do I need a FMU if I don't have a supercharger installed on my car? I'm asking because, I recently bought a 87 Mustang the came with a FMU already installed and it has an extra rib in front of the crank pulley, which looks like it was meant to run the belt for the supercharger that was once installed. Should I remove the FMU? It seems like my car is running rich, very rich. I get a lot of smoke from my pipes when I pull off from a light. As far as the crank pulley, does anyone think that I need to replace it with a regular crank pulley, or even a underdrive crank pulley? Am I losing power for having this extra set of ribs in front on my serpentine belt? Thanks for any replies. __________________ 87 GT As of 2/1/06 650 DP Carb Crosswind Intake Edelbrock Performer Heads 97 Explorer Bottomend w/ B-303 Cam 1.7 Roller Rockers Flowtech Longtube Headers Flowtech H-Pipe MSD Black Wires MSD ignition MSD Distributor Blaster 3 Coil Electric Fan Underdrive Pullies T5 Trans Hurst Shifter Lowered 1.5" 373 Gears

05-14-2003, 08:22 AM	#2
302 LX Eric or '331 LX Eric' Join Date: Jan 1999 Location: Columbus, Ohio Posts: 2,142	No, you don't need the FMU. The FMU should only be working under boosted conditions anyways, so I don't think it's even doing anything for you. I would just stick an adjustable FPR on there and set it factory pressure (about 39psi) and be done with it. E __________________ 1991 5.0 LX Coupe - 40,750 miles 331 cu. in. / Tremec 3550 / BFG Drag Radials 12.22 @ 114.31 mph - w/1.89 60'

05-14-2003, 08:55 AM	#3
NitroNixon Registered Member Join Date: Mar 2002 Location: DC Posts: 129	Thanks for the reply, I get a adj. regulator then, so should I leave the FMU in the car then? __________________ 87 GT As of 2/1/06 650 DP Carb Crosswind Intake Edelbrock Performer Heads 97 Explorer Bottomend w/ B-303 Cam 1.7 Roller Rockers Flowtech Longtube Headers Flowtech H-Pipe MSD Black Wires MSD ignition MSD Distributor Blaster 3 Coil Electric Fan Underdrive Pullies T5 Trans Hurst Shifter Lowered 1.5" 373 Gears

05-14-2003, 08:06 PM	#4
Stang_Crazy It's never clean enough! Join Date: Jan 1999 Location: Shaler, PA Posts: 1,542	No, you don't need the FMU anymore. Just grab an adj. FP regulator and ditch the FMU. __________________ ~Dan 2001 SVT Lightning 89' GT : Taking up garage space and waiting for a buyer... Rice Hater's Club - Member #11