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Exedy clutch

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Grant 302

basic and well known psychic
Anywho, i feel like we should all know this by now 7+ years later.

To be clear for everyone, it does appear that is mainly an issue with the OEM stamped housing and deflection/expansion at high temp and over 7,000 RPM. Before Boss2620 made the call to Exedy, I was certain that the problem was between the Housing and Diaphragm and not the disc. Either the fulcrum point/ring on the plate moved, and/or the fingers/diaphragm deformed under those conditions. Unfortunately, that was all just theoretical.

But after I talked to Boss2620 about this:
He was familiar with the issue and thought the cause was deflection of the pressure plate housing at high rpm.

To me, the issue and the solutions are 100% clear now.

Pick the disc you want for your application and use. Brand-wise I'd favor Exedy myself - because they clearly understand the issue, but I'm sure that the McLeod housing is at the very least better than the OEM one, even if their disc is not as durable. I do not recall anyone having shifting issues with either RST or RXT - Just the broken discs reported as far as I know.

For the newer members or anyone who doesn't know - I have both '11 GT and '12 Boss. I have zero issues with the GT's OEM clutch and shifting at the stock GT rev limit. My Boss only has the lockout/soft pedal problem when hot and shifting anywhere near 7,500 at least a few times in a row. It has gotten incrementally worse over the years presumably from wear of the disc material, which worsens the geometry for mechanical clutch release.

Bosses do not all have the same shifter from the factory. The gates on my '12 are much tighter and notchier than all the '13s I have been in, which are much like my GT in feel and spacing.
 
24
47
Exp. Type
HPDE
Exp. Level
5-10 Years
San Diego
Boss2620,

I too think you will be extremely happy with the Exedy set-up as you describe. My install is also comprised of the Exedy Racing Stage 1 Organic Clutch kit (07807csc) w/the Exedy Aluminum Flywheel (EF502A). The MGW Short Throw Shifter, Shelby ISO Clutch Resevoir (384320), and Whiteline Transmission Mount Bushing Insert (KDT928) and Exedy combination completely eliminated high RPM/lateral torque lock outs I had also experienced with my 2012 Boss. My 302 is a daily driver that is driven to/from 3-4 HPDE events a year in SoCal. Since I have no engine modifications, the Racing Stage 1 variant also recommended to me by Exedy serves my purposes well.

This particular set-up also exhibits impeccable road manners and is quite a comfortable vehicle for my wife to drive on local grocery runs at low speed/low RPM with the occasional "oops, I think I started (from a red light) in 2nd gear" excursions.
 

Grant 302

basic and well known psychic
Are the both 8 bolt?
All modern Coyote variants are, as far as I know. I'm talking about the pins between the flywheel and the pressure plate housing. GT and Boss are different.

In order to use an aftermarket clutch, Boss owners must switch to a GT style flywheel as all aftermarket clutch and flywheel parts are for the GT format.
 

Grant 302

basic and well known psychic
Boss2620,

I too think you will be extremely happy with the Exedy set-up as you describe. My install is also comprised of the Exedy Racing Stage 1 Organic Clutch kit (07807csc) w/the Exedy Aluminum Flywheel (EF502A). The MGW Short Throw Shifter, Shelby ISO Clutch Resevoir (384320), and Whiteline Transmission Mount Bushing Insert (KDT928) and Exedy combination completely eliminated high RPM/lateral torque lock outs I had also experienced with my 2012 Boss. My 302 is a daily driver that is driven to/from 3-4 HPDE events a year in SoCal. Since I have no engine modifications, the Racing Stage 1 variant also recommended to me by Exedy serves my purposes well.

This particular set-up also exhibits impeccable road manners and is quite a comfortable vehicle for my wife to drive on local grocery runs at low speed/low RPM with the occasional "oops, I think I started (from a red light) in 2nd gear" excursions.

Welcome to TMO, Dennis...and thanks for posting. :cool:
 
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38
I just got my Stage 1 07807 with the lightened billet flywheel installed and bled the clutch to see what the pedal effort will be.
All I know is that the Exedy requires a lot more pedal effort than stock.
 
218
369
Exp. Type
Time Attack
Exp. Level
5-10 Years
CA
Recommend against staying with the stock clutch. Its the cause of the majority of shift lockout issues and synchro damage.

My bad. I forgot about this issue as I rarely experienced it. But I don´t have a Boss either. Listen to Swine.

On the other hand, the MGW did not change anything for me. For me the car shifts the same, just has more NVH. This is completely subjective, but in my experience the MGW is a bit overrated. Again, not a Boss and I shift at 6900.
 

TMSBOSS

Spending my pension on car parts and track fees.
7,529
5,242
Exp. Type
HPDE
Exp. Level
10-20 Years
Illinois
As they say. YMMV

While chasing lockouts on the Boss. The first change I made was the shifter. I did this for two reasons. The shifter felt too vague and I had lockout issues. The MGW solved 90%+ of the lockouts. The other 10% came with the clutch change. Shifting at 7400 RPMs was a crap shoot. Sometimes she would, others....not so much.

When I first drove my Boss, the shifter was my only disappointment. I grew up on Hurst competition plus shifters and four speeds. Loved them. When I went looking for a replacement for the Boss, Hurst was a disappointment. The MGW I put in both Mustangs. Never regretted the move.
 
My bad. I forgot about this issue as I rarely experienced it. But I don´t have a Boss either. Listen to Swine.

On the other hand, the MGW did not change anything for me. For me the car shifts the same, just has more NVH. This is completely subjective, but in my experience the MGW is a bit overrated. Again, not a Boss and I shift at 6900.

I do agree on the MGW being somewhat overrated, not to say it doesnt perform well. It just didnt make my shifting experience go from "terrible" to "amazing" like lore may lead you to believe. The stock shifter has never really given me problems, but my stock Boss clutch has 100% :)
 
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253
RST was the only thing that cured the lockout for me. MGW, Blowfish, stainless clutch line, Whiteline bushing, Spec Stg 1 and alloy flywheel - none of them had any effect. RST fixed it immediately. If I bought another Boss, the very first thing I would do to it would be a clutch upgrade so that you can fully enjoy the revs.
 
Well it’s been awhile and I wanted to be sure. The Exedy Stage One (Mach 500) and the Exedy light weight chrome moly flywheel work perfectly. It’s like driving with a stock clutch on the street but without any lockout at any rpm. I also installed the MGW Racespec shifter (standard/ standard) and the combination made me fall in love all over again. The clutch is rated for almost 600 lb/ft of torque at the rear wheels so even with power adders it will hold up. I can fully recommend this combination. I have zero chatter like you sometimes get with the ceramic metallic disc of the Hyper Single and will last much longer, it’s the fix I’ve been looking for for 6 1/2 years!
 
6,360
8,180
IT depends, that's probably the top limit, but, the road race guys run almost as much in some of the SCCA classes (maybe more) plus a ton of hard shifting, and they seem to live there.
 
898
544
Do you think the Exedy Hyper Single would be ok for 470 to 480 rwhp???

It is torque, not horsepower that breaks a clutch and drive line parts. Excedy rates the S197 Hyper Single kits torque capacity at 506 ft /lbs - which is a lot more torque than a normally aspirated Coyote motor can typically produce.
 

Mad Hatter

Gotta go Faster
5,237
4,227
Santiago, Chile
It is torque, not horsepower that breaks a clutch and drive line parts. Excedy rates the S197 Hyper Single kits torque capacity at 506 ft /lbsn - which is a lot more torque than a normally aspirated Coyote motor can typically produce.

True, just was not sure if that was at the wheels or at the engine. I must be a little over 400 rw torque, or 470 ft/lbs to the motor. My almost new Spec 3 clutch was for 700 ft/lbs but it lasted 4 track hours. The previous Spec 2+ lasted four seasons and still looked fine, but with less power.
 

Bill Pemberton

0ld Ford Automotive Racing Terror
8,420
8,346
Exp. Type
Time Attack
Exp. Level
20+ Years
Blair, Nebraska
Would have to politely disagree with those who did not think the MGW did not make a big difference, because the issue is not just to help with smoother shifts, but as a major assist keep from missing a shift. I do not think I have ever seen a Boss S without an MGW short throw shift kit in it. The best thing going is George Ciamillo is continually making improvements on his shifter and not by schematic drawings, pictures or specs , but by personally buying numerous Mustangs over the years. I'd estimate you would need both hands and feet to count all the Mustangs George bought to get real World feeling built into the systems and I am likely light on the number. Best acknowledgement is seeing all the Ford Engineers who have his system in their cars.
I am biased because I have worked or known George for over 20 years and when he was building a similar unit for the Viper , it was a very frequent install for Viper TrackRats that purchased a car from Woodhouse Chrysler, Dodge, Jeep, Ram, Ford. We worked with him perfecting a shifter that not only was tighter and smoother but really helped avoid the dreaded missed downshift. That is common mistake that seems to rear it's ugly head with all manuals and upshifts or downshifts are clicked off with his shifter in a Mustang.
He loves the same car we all do, but he does R&D on his own car and then purchases another to work on when things change ---- he does not stop improving the product.
 

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