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Exedy Mach 500 (clutch)

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zzyzx

Steve
299
0
Looking for feedback on the Exedy Mach 500 clutch.

Anybody here have first hand experience with this clutch in your Mustang?

http://www.americanmuscle.com/exedy-stage1-clutch-2011gt.html

I've had good luck with Exedy clutches before, and this was recommended to me.

I'm not interested in a clutch that will withstand brutal amounts of torque. I'm looking for a clutch that will reliably and consistently operate at 7500+ RPM at the track.

At this point I have zero power mods and would eventually go with typical bolt ons and a tune, but never FI.

I have the dreaded high RPM clutch issue and though I intend to try to have the dealer handle the issue, I'm preparing for the eventuality that they will chose not to.

Thanks for any feedback!
 
In for feedback.
 

zzyzx

Steve
299
0
I just pulled the trigger on this clutch. What info I did get about it is by and large positive, and it will be going in likely late next week. I'll follow up with details/feedback in this thread later, so stay tuned.
 
I can vouch that they're solid clutches. I ran one for 20,000 miles in my 5.0 They have just a bit stiffer pedal and a grab like hell. I was doing 3k drops at the track with 305 DR's with consistent 1.8 60ft.

When I got my kit they came with replacement slave cylinder and throw out bearing. I don't think they come with the slave now. Anyways, you'll have to get a steel flywheel because at least with 5.0 stock flywheels they cannot be turned. I had a ram flywheel.
 

zzyzx

Steve
299
0
Update:

Ok, been on the Exedy Mach 500 clutch for about two weeks now - including one very fast / on the rev limiter in 2nd gear - autocross event.

I opted to have the dealer install the aftermarket clutch as opposed to a new OEM clutch because I was having the clutch pedal weakness/drop issue and since there's no upgraded part number to actually fix the issue, I didn't want to continue to endure it, even though that means I'm now on a clutch that obviously won't be under warranty for any new issues that come up.

The parts:

I've used Exedy clutches and flywheels before and the quality is top notch. They make a lot of OEM applications, and it's obvious. There are many options out there, but I would have a hard time justifying another make as I've never had a problem with an Exedy product so far...

Installation:

Beware, as this is not as straightforward as Exedy or those selling their parts would have you think.

The Boss 302 uses an 8 bolt clutch and flywheel, whereas the GT uses a 6 bolt. Also, note that the bolts that need to be used are the Ford OEM bolts for a GT, not a Boss as the Boss bolts are too long.

I didn't find this out until I got a call informing me that the clutch won't mate up to the stock flywheel. So, I overnighted an Exedy lightweight flywheel and had both the clutch and flywheel replaced together. Not bad thing mind you, but unexpected. I did not use the Exedy slave cylinder, though I probably should have while I was at it. I also made sure to give them a bottle of Motul RBF600 so they wouldn't put low temp brake fluid in and they used nearly the entire bottle.

Use:

When I first received the Boss after the install, I could still feel a distinct loss of pedal effort by simply pushing on the clutch lightly - about 1/5 of the travel - and reving the engine to 5-6k RPMs. This was not reassuring. The tech reminded me it'll need to be bled (by use...), and at this point, that weakness is 99% gone. I've made a point of pumping the pedal 20-30 times at every stop. This leads be to believe that the root cause of the weak pedal is likely a combination of weak clutch return springs coupled with hydraulics that are not up to snuff - specifically the slave cylinder.

The pedal effort is markedly increased, but not annoyingly so. It's different enough such that it would never be confused with a stock clutch. Note that I had previously removed my clutch return spring, so re-installing may be a good idea at this point.

The clutch action is smooth as butter, linear and progressive. It's exactly like the stock clutch or better in this regard and this is what I was after - I did not want an on/off switch for a clutch. So I'm very pleased that it's basically identical to stock.

I expected to feel more of a difference due to less mass in the flywheel, but it's also nearly identical to stock in terms of feel. Perhaps just a tad more "herky jerky" in the really low RPM 1st gear stuff, but that's easily avoided. I don't have the TracKey installed, so my Boss neither revs instantly nor decels instantly, so hard to see any difference there.

The noises generated after the replacement are quite different. Bottom line, I hear more gear noise and I think I can hear the throwout bearing. Not sure on the later. I attribute most of this to the flywheel which is lighter. I also get a distinct high pitched resonating ring sound right at 83-83 MPH in 6th gear, prominent when accelerating. It sounds like the flywheel is resonating with the vibrations coming through the tranny. At idle I sometimes hear some added noise, but it's very faint.

I have a DSS CF driveshaft waiting to go in and I'm hoping that will quell a lot of the noise. I hear that the CF is a good noise damper.

I haven't yet tracked the Boss since the clutch replacement, but I had no problems at the autox which was fast and had multiple 2-3 and 3-2 shift points where I never felt a weak clutch. Won't know for sure until I get back to the track. That said, I don't expect to have a problem. I had previously gone to Homestead on the OEM clutch w/o the return spring and didn't actually have a problem, though the number of shift points per lap was really low - I only used 3rd and 4th gears.

Last weekend (at around 8000 MI) I changed the tranny and rear diff fluids. I put Redline Shockproof Lightweight in both. I've used Smurf Oil (yes, it's baby blue in color...) for many years in finicky trannies with success. The fluid change resulted in smoother shifts and a little less noise overall. A positive change overall, but nothing drastic.
 
Steve, thanks for the update. I also hear more noise with mine and I'm not sure why that is. It certainly wasn't expected but then I've never installed a high performance aftermarket clutch in a car before.

It's pretty clear to me the clutch is not the problem for the soft and sticking pedal. While removing the springs seems to "solve" that issue I doubt it's the cause. I agree that it has something to do with the slave and hydraulics. If you were having problems with the pedal sticking I'd be careful reinstalling the helper spring.

I do think the clutch is most of the problem with shifting lockout and I didn't miss a single shift last Friday at Thunderhill.

I'm curious about your CF DSS driveshaft so keep us posted.
 
Sorry for a VERY late response here but a question: Did you actually follow the instructions and drove a 500-1000 mile break in period? All the engine builders said that I don't need to do that because it's an organic clutch. Fitted on my 2012 Boss last Monday (with modifications to the flywheel because the stock one didn't fit).... Very thankful for replies.
 
Can you expand on what modifications you did to the flywheel??
Changed the dowelpins but when I put the clutch up there where no holes at all to tighten it down. I removed the flywheel and took it to local engine builder and tuner who drilled new holes, balanced and resurfaced. Super glad I did because the stock flywheel at least on my car is apparently. The balance was off by 5.39 oz and it had a wobble of 0.0157"
If I ever wanted to return to a stock cluch I can on the stock flywheel. The balance is now off by: 0.053 oz with the pressure plated attached so it won't get closer. Attached some pics of the flywheel after the job was done.

I'm Swedish so I misspelled something it's not my native language :). Also I converted the values from Metric to Imperial.

2020-05-30 18.01.54.jpg

2020-05-30 18.02.05.jpg





2020-05-30 18.02.29.jpg
 
6,361
8,181
why did you choose the mach 500 over the hyper single?, generally the hyper single is considered the go to clutch for the boss 302 platform. in any case, anything is probably a better choice than the stock style clutch.
there are generally 3 types of clutches, 3 finger, Borg and Beck, and diaphragm style clutches. One bit of nastiness is that if the throwout bearing is not properly adjusted, the diaphragm clutch can "over center" and stay stuck to the floor, when the RPM drops, it will suddenly pop back up.( I saw this happen in a buddy's 66 GTO, quite an eye opener) it can sometimes happen when the clutch disc itself has not been built to "spec" with too big of a gap between the flywheel and the pressure plate, or too much wear on the pressure plate combined with the above.
you guys need to use the Ford recommended lubricants in the trans, they no longer have brass synchros, but a friction material like an automatic clutch pack, and once they are saturated with whatever fluid they come with, they seem to like to stay that way, changing the type of fluid can get sketchy. (the rebuild on the junkyard dog had this happen to it by a prior owner)
 
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I was curious why you would not just get another fly wheel. Then I saw your location. Reworking the original likely saved you 30 days delay with shipping and taxes.

I waited from late February - early March and the clutch arrived 2 weeks ago so yes it's a pain in the ... to get stuff over here during the pandemic :(.

[
why did you choose the mach 500 over the hyper single?, generally the hyper single is considered the go to clutch for the boss 302 platform. in any case, anything is probably a better choice than the stock style clutch.
there are generally 3 types of clutches, 3 finger, Borg and Beck, and diaphragm style clutches. One bit of nastiness is that if the throwout bearing is not properly adjusted, the diaphragm clutch can "over center" and stay stuck to the floor, when the RPM drops, it will suddenly pop back up.( I saw this happen in a buddy's 66 GTO, quite an eye opener) it can sometimes happen when the clutch disc itself has not been built to "spec" with too big of a gap between the flywheel and the pressure plate, or too much wear on the pressure plate combined with the above.
you guys need to use the Ford recommended lubricants in the trans, they no longer have brass synchros, but a friction material like an automatic clutch pack, and once they are saturated with whatever fluid they come with, they seem to like to stay that way, changing the type of fluid can get sketchy. (the rebuild on the junkyard dog had this happen to it by a prior owner)


I choose the Mach 500 because it seemed like a resonable price with pretty good reviews and the kit included everything.

Regarding the gearbox oil I didn't go with the Ford recommendation. I went with the Ben Calimer Mix because I've read that's the way to go in the MT/82. Also have a few Boss 302 friends that use that with less issue then with the Ford spec one.

My question still remains :) Would you actually break in a organic clutch for 500-1000 miles? Sounds so weird. If you buy a brand new car you don't break the clutch in. As I said earlier all the engine builders around here said it was very weird.
 

xr7

TMO Addict?
706
821
Exp. Type
Autocross
Exp. Level
10-20 Years
Minnesota
You don't have to break in a clutch on a new car, its already been done for you by all the people that have already driven the vehicle since it left the assembly line.😱
 
You don't have to break in a clutch on a new car, its already been done for you by all the people that have already driven the vehicle since it left the assembly line.😱

Ehh... They drive the cars maximum 10-20 miles and that is the absolute max. Including the transport on and off the trailer. All the cars I've bought new has had around 5-10 miles on the odometer.
 

Grant 302

basic and well known psychic
Ehh... They drive the cars maximum 10-20 miles and that is the absolute max. Including the transport on and off the trailer. All the cars I've bought new has had around 5-10 miles on the odometer.
I think he’s kidding.

I think the recommendation is way on the conservative side. But I don’t see it being that difficult to get to 500 miles.
 

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