Exedy clutch

Discussion in 'S197 Technical Forum - GT, Boss 302 and GT500' started by Boss2620, Jan 19, 2019.

  1. Boss2620

    Boss2620 TMO Intermediate

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    I spoke to Evan Kline at Exedy about a fix for our Boss clutch problem. I explained that the Hyper Single seemed to be the hot setup and asked him what his opinion was. He was familiar with the issue and thought the cause was deflection of the pressure plate housing at high rpm. He didn’t think the Hyper Single was the best option though if your primary usage was street driving. He suggested to use their Stage 1 racing clutch and mustang GT flywheel or one of their lightened flywheels. Exedy doesn’t make a clutch that will directly bolt to a Boss flywheel so no matter which Exedy clutch you use it will require a flywheel change in our Bosses. He said all their clutches are tested for functionality at 18000 rpm and their pressure plate assembly was made with sheet metal that is approximately twice the thickness of the OEM unit. He said their Stage 1 unit weighs two pounds more than the stock Boss pressure plate due to the beefed up housing and theirs is much more rigid. He told me that the organic material disc would last twice as long as their ceramic disc and would have better street manners. Has anyone tried the Exedy Stage 1 racing clutch and if so what were your results on the track at high rpm?
     
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  2. 80KM2E

    80KM2E Canada, Eh?

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    Yes The Stage 1 or "mach 500" 07807CSC with Exedy lightened Flywheel EF502 is what I've been using after my OEM exploded on track. Its held up great so far for mixed use and was very cheap! Once this one explodes or wears out I'll likely go for the Hyper Single - just because.
     
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  3. gww52

    gww52 TMO Advanced

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    I have the Stage 1 ready to install.
    Sounds like I made the right choice.
     
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  4. Grant 302

    Grant 302 OPM Spent: $665,833 Moderator

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    Get it in there! :) :D
     
  5. Boss2620

    Boss2620 TMO Intermediate

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    Gww52 let us know how it works out. Which flywheel will you be using?
     
  6. Boss2620

    Boss2620 TMO Intermediate

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    80KM2E did this setup solve the high rpm lockout?
     
  7. Grant 302

    Grant 302 OPM Spent: $665,833 Moderator

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    Looks like he has a GT. Should have solved his exploding clutch issue though!
     
  8. gww52

    gww52 TMO Advanced

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    I'm using the Exedy light weight flywheel and its a Boss 302.
    My original clutch has never been a problem but the springs in the disc have me concerned, hence the changeout.
    I also have a Calimer Stage 1 ready to go.
    My MT82 has never given me trouble but 31,000 miles and lots of track time I think it's a good idea.
     
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  9. blacksheep-1

    blacksheep-1 TMO Addict

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    Surprised to find that he doesn't recommend the Exedy Hyper Single since every PWC, IMSA, TA and SCCA Boss 302 that I've ever seen or heard from uses one.
     
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  10. 2012-Boss

    2012-Boss TMO Addict

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    I think the recommendation is for a street car that is used for some track days. Keep in mind that the Hyper Single disks are extremely thin compared to a more street oriented clutch. Brand new, the Hyper Single disk is only 6mm thick, that includes both sides of the friction surface and the metal disk they are bonded to. I suspect that repeated stop and go street use would rapidly wear the Single out compared to a thicker OEM style disk.

    For pure track use, the Hyper Single is awesome. I have three seasons on mine and when I had it out this winter it still measured over 5mm thick.

    I do wish Exedy made an aluminum flywheel for our cars...
     
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  11. smallblock

    smallblock TMO Race

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    I have the Exedy Mach 500 Clutch and stock flywheel on my dual purpose 11 GT. It makes 440 RWHP at 7400RPM redline. It has been great. No lock-outs, drives like stock, just a stiffer pedal. About 15,000 miles on it so far.
     
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  12. Badger

    Badger TMO Intermediate

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    I got an Exedy Hyper Single and I can second it`s a bit odd for street driving. The car tends to clank and shatter and is easy to stall. It doesn't bother me much but passengers are always highly confused.
    All that aside, it functions spot on on track. I´m running an s197 though and shift at 7.000rpm.
     
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  13. Boss2620

    Boss2620 TMO Intermediate

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    I'm going with the Stage I (mach 500) and the Exedy lightened flywheel. I've spoke with enough Boss owners that are using that setup, that really like it, so I'm convinced that will work the best for my situation. Actually I've spoken to Boss owners who are using the Mach 500, Mach 600 and the Hyper Single and all these Exedy clutch kits seem to perform without a hitch. I'll let you know after the install if I'm truly happy.
     
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  14. smallblock

    smallblock TMO Race

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    I think you will be happy especially if it’s a dual purpose. It behaves much like stock but shifts at higher RPM with slightly higher pedal pressure. Can’t speak to the light weight flywheel tho.
     
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  15. Opolis

    Opolis TMO Intermediate

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    Good to hear some input on this. I know everyone says Hyper single but my car is mostly driven on the street and I have been eyeing the Exedy Mach 500 and maybe the lightened flywheel. I only have CAI+tune and am looking for something better than stock that I can still drive around town. I am very experienced at explaining to passengers why things are not as comfortable as they expect:cool:
     
  16. Badger

    Badger TMO Intermediate

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    Sunday I spend 4 hours in heavy LA traffic. The Hyper Single was no burden whatsoever. It`s only annoying when you got to back up or drive at less than walking speed.

    You are on almost stock power. I`d keep the OEM one till it`s a goner.
     
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  17. Swine

    Swine TMO Advanced

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    Recommend against staying with the stock clutch. Its the cause of the majority of shift lockout issues and synchro damage. First thing any Boss owner should do is replace the clutch. My two prior S197 MT82 coyotes never had issues, my stock as a box of rocks Boss had a ~25% shift failure rate trying to snap hi rpm gear changes. Seems the oem higher rated Boss clutch had higher "failure" or a higher % of issues then standard mustang clutches either due to design, higher rpm loading of the boss redline, or most likely both.

    Anywho, i feel like we should all know this by now 7+ years later. Im open to feedback if anyone feels i am mistaken.
     
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  18. TMSBOSS

    TMSBOSS TMO Addict

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    Swine. Spot on.

    One addition, add the MGW shifter. Most of the improvement with the MGW is in feel. The stock unit it so loose, the MGW gives you confidence the trans is going into the gear YOU desire.
     
  19. 2012Boss302

    2012Boss302 TMO Addict

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    Stupid question, what's the difference between the Boss flywheel and the GT flywheel???
     
  20. Grant 302

    Grant 302 OPM Spent: $665,833 Moderator

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    They're pinned differently and parts will not cross-bolt.
     
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