Steve Baur
Former Editor, Modified Mustangs & Fords
January 25, 2007

Step By Step

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Mmfp_0310_01_z Clutch_masters_drivetrain_upgrade LaunchingMmfp_0310_02_z Clutch_masters_drivetrain_upgrade New_clutch
The Clutch Masters FX 300 system retails for $626.40 and comes with pilot and throw-out bearings, and the clutch alignment tool.
Mmfp_0310_03_z Clutch_masters_drivetrain_upgrade New_flywheel
The CM aluminum flywheel weighs about 9 lbs. less than the stock one and lists for $429. It can improve the efficiency of supercharged engines and reduce turbo lag in hairdryer applications. The CM clutch kit and flywheel can be purchased together for just $715.
Mmfp_0310_04_z Clutch_masters_drivetrain_upgrade Shifter
Removing the shifter handle is the first priority in a clutch change. Using a quality aftermarket shifter the like the Pro 5.0 unit pictured here will help you get those gear changes more easily.
Mmfp_0310_05_z Clutch_masters_drivetrain_upgrade Exhaust_removed
Next, we removed the exhaust system. If you have shorty headers, it's just a matter of pulling off the H-pipe, but as you can see, our monster long tubes required a little more disassembly.
Mmfp_0310_06_z Clutch_masters_drivetrain_upgrade Long_tube_headers
The clutch cable can be released at the fork by removing the inspection cover and then prying the fork forward enough to release the cable.
Mmfp_0310_07_z Clutch_masters_drivetrain_upgrade Removing_the_transmission
With the cable released and the exhaust out of the way, the driveshaft is next followed by the transmission.

Failure is not a good thing. Especially when you have the highest hopes prior to its occurrence. We were hoping to put down some blistering elapsed times with our ProCharged Mustang GT, but the combination of molasses-like BFGoodrich drag radials and 330 rwhp proved to be too much for the stock replacement clutch that had been living in the trans tunnel for the past few years.

In the August 2003 issue of Muscle Mustangs & Fast Fords, we installed a complete street/strip exhaust system from Bassani, and when we went to the track to test it out, the clutch slipped; a problem only exacerbated with the addition of drag radials. For that reason, we never got back to the dyno to check our results. By the time we got the new clutch installed, we were again unable to get to the dyno as our story deadline and other scheduling issues arose. We were, however, able to bring you some track results, which is quite amazing given the monsoon spring that we had. Before we do that, let's take a look at Clutch Masters, and how they were able to put all of our supercharged power to the ground.

Like our recently installed Bassani exhaust system, we wanted a clutch that would be capable of handling even more horsepower than the motor currently produces. After all, we're horsepower junkies just like you and if 330 is great, 500 is better. That being said, we contacted Clutch Masters of Rialto, California, and asked them what they recommended for our combination.

Clutch Masters has a disk for just about everything and every power level. Its FX 100 starts out with an organic clutch disk along with a diaphragm pressure plate that uses the company's high-leverage system. The high-leverage pressure plate is designed to eliminate crank walk and thus thrust bearing failures. The higher leverage action also allows the use of a heavier clamping pressure, without the heavy pedal to push.

Stage 2 moves up to a Kevlar clutch disk, and Stage 3 uses a segmented Kevlar disk for even greater power-holding capability. "The segmented design traps air, and that air gap allows the disk to handle more power" said Clutch Masters Manager Lonny Futch. "Kevlar also lasts two-to-three times longer than an organic impregnated disk." The FX 300 uses the same high-leverage pressure plate and still offers a smooth clutch engagement for good drivability.

In our February 2003 issue, David Vizard tested Clutch Master's aluminum flywheel on three different cars and came away with promising results. After talking with Lonny, we felt it would be best (both safety-wise and performance-wise) if we replaced our stock 140,000-mile steel flywheel with one of Clutch Master's lightweight units.

This two-piece flywheel meets SFI spec 1.1 or 1.2, and uses a backing plate made from 6061-T6 aircraft grade aluminum and an A36 steel clutch surface for weight savings and better wear characteristics. Included with the flywheel are both 28 and 50oz counterweights (used according to your rotating assembly) that are secured to the flywheel via the provided hardware. An OEM-style ring gear is also employed and secured to the flywheel with removable bolts. Think of it as a modular flywheel. Each part is independently replaceable. You can purchase the clutch and flywheel separately, but we opted for the discounted clutch/flywheel package, which sells for $715.

Installation is no different than with any other clutch and flywheel system. Clutch Masters includes the clutch alignment tool, throw-out bearing, pilot bearing, and of course, the clutch itself. Dan Ryder of Danny's Pro Performance in Keyport, New Jersey, handled the installation. The job would have taken just a couple of hours, but having to remove the slip collectors on both sides of our long tube headers and loosen them on the passenger side to get the bellhousing out took extra time. If you have shorties, you'll be done quicker than you can say sidestep.

While you're replacing the clutch, it is a good time to inspect the bearing retainer on the transmission and change the fluid in the unit. When we pulled the transmission out, part of the bearing retainer slid out and got lodged in the clutch mechanism. Luckily, Danny had a new steel bearing retainer that we could throw on. We also drained the fluid from the T-5 and filled it with Castrol synthetic ATF. This will help the trans live a little longer under the punishment of our supercharged steed.

While a clutch is not necessarily a performance-enhancing item, an aluminum flywheel can be. The clutch just makes sure you can use everything you've got. Prior to the clutch installation, we had made runs with and without the Bassani exhaust system, and with the factory shorty headers and on street tires, the Mustang ran a best e.t. of 12.87 seconds at 112 mph. This was in 28 degree weather no less. We tried to test the car right after the Bassani installation, but that's when our clutch problems began. The temperature had risen to around 60 by then, and we managed a 12.98 seconds at 109 mph before the clutch started slipping in third and fourth gear.

With our new Clutch Master FX 300 and aluminum flywheel on board, we clicked off a 12.82 seconds at 110 mph in still warmer weather. This improvement was no doubt the result of a clutch that didn't slip, but also the performance of the Bassani exhaust and the aluminum flywheel.

Here you can see how our O2 sensors have been rerouted to fit the long tube headers. You can also see how part of the bearing retainer from the transmission was lodged in the clutch assembly.

If we can say one thing about the flywheel, it's that drivability has increased quite a bit. The engine feels much more unrestrained, and the lugging and jerking that we experienced with the steel unit is gone-replaced with a smooth and eager engagement. At the track, the new clutch bit hard during every gear change, and the engagement allowed us to slip the clutch just enough to get the car out of the hole in a timely fashion-at least considering that we were dealing with a factory 2.73:1 ring-and-pinion ratio. Now that we had the holding power to harness the ProCharger's 389 lb-ft of torque, it was time to slash elapsed times with an improved ring-and-pinion ratio.

Pro 5.0, the name you know for its aftermarket shifters, also sells ring-and-pinion sets, so we called them up for a set of 3.55 gears ($199.00). We didn't want any problems with the law either, so we needed a speedometer correction gear for the speedometer cable. A simple call to Downs Ford in Toms River, New Jersey, was made and Joe Amato had the little white gear sitting on our desk in just a few days. Dan Garrity of Danny's Pro Performance handled the ring-and-pinion installation in about two hours. We filled the differential up with some Castrol 75W/90 synthetic gear oil, along with a tube of friction modifier for the Traction-Lok, and then it was time to hit the track once more.

We were able to put a few hundred miles on the gear set before we took to the track, and by the time we did, the spring rains that seemed to come every other day parted, to let the blazing sun cook us on the track. Since traction was an issue with the 2.73 gears, we knew we had to step it up if we wanted to see some low elapsed times as the new ratio would certainly cause more wheel spin. For this, we looked to BFGoodrich and its drag radial tires.

Our car was equipped with Ford Racing's Cobra four-wheel disk brake conversion, and the larger rotors require special offset rims if you want to use a 15-inch slick. While BFG offers drag radials in 15-inch sizes, they make them in 16- and 17-inch sizes as well. We had two '99-spec 17x8-inch Cobra rims taking up space in the office, so it seemed like a perfect match.

Fox-bodies are not known for their large fenderwell areas, and since we were dealing with an 8-inch-wide wheel, we could only go with the 275/40/17 drag radial. When Steeda gave us its Q400 to wring out, they happily included an identical set of these sticky tires. The BFG's handled 4,000-rpm launches like a charm, so we had to get a set for ourselves.

Something's amiss here. We replaced the old bearing retainer with a new steel unit that Danny's Pro Performance had at the shop. If you are still running the original transmission, you may need to change this, as the stock aluminum ones become scored and often inhibit smooth bearing travel.

On the Cobra wheel, the 275s stick out but not obtrusively. Hitting potholes (a common occurrence in the Garden State) will certainly bring them in contact with the wheelwell lip, so if you want to leave them on, go with a 9-inch wheel with an extra inch of backspacing and you should be set. The drag radials, unlike street slicks, have an actual tread that works in inclement weather should you get stuck in the rain. They also have a very soft and sticky compound that gets the job done on the strip.

And speaking of the strip, with the drag radials heated, the 3.55 gears poised, and the Clutch Masters FX300 waiting, we made quite an impact on our elapsed times despite blistering 90-degree temperatures. The first run was a get-acquainted 12.73 seconds at 110 mph. Then, we slipped the clutch to a 1.90 short time and tripped the clocks in 12.58 seconds at 110. If it were not for the BFG's, we would not have been able to get down the track at all as the track surface went away as the day wore on. Two more runs, a 12.77 and a 12.68 were also logged, but by this time, we were fighting Mother Nature.

The Pro 5.0 gears made quite the impact on e.t., but it wouldn't have been possible without the grip of the Clutch Master's FX 300 system and the ability of the BFGoodrich drag radials to put it to the ground. Had we seen cooler ambient temperatures, there may have been an even greater improvement in elapsed time, but we'll take three-tenths, and the confidence that our clutch can handle whatever we throw at it.

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