Ford GT Clutch kit questions

[Daniel_Iaciu]

Hello, I have a newly acquired Ford GT 2006 coming in soon! I was looking for replacement clutch kits and I see there's an OEM alternative coming as a kit with everything you need for the service, but I see SPEC also offers an aftermarket alternative for high power applications. The Ford GT I ordered is a Whipple 4.0 setup, so would it be worth it to go with the SPEC aftermarket alternative, or go with stock? Links for both below.

Stock:

FORD GT PRODUCTION CLUTCH KIT -- M-7560-GT

FORD GT PRODUCTION CLUTCH KIT -- M-7560-GT

www.fordracingbyspeedshopdirect.com

SPEC Aftermarket alternative:

SPEC Super Twin Clutch Kit E-Trim: Ford GT 5.4L #SGTET

SPEC Super Twin Clutch Kit E-Trim: Ford GT 5.4L #SGTET

www.lmperformance.com

Thank you in advance for help!

 

[mmlcobra]

It really depends on how you drive and the venue.
My Heffner twin turbo car is driven on the street.
Not much abuse.
Stock clutch appears to be fine.
Enjoy!
Best,
Mark

 

[Daniel_Iaciu]

It really depends on how you drive and the venue.
My Heffner twin turbo car is driven on the street.
Not much abuse.
Stock clutch appears to be fine.
Enjoy!
Best,
Mark

Have you had to replace the clutch yet? If so, after how many miles?

 

[mmlcobra]

Have you had to replace the clutch yet? If so, after how many miles?

Original clutch.
6500 miles.

 

[Daniel_Iaciu]

Original clutch.
6500 miles.

Gotcha! The GT I purchased is at 16.5K miles and from my understanding got the 4.0 whipple + other mods around 2K miles. I'm hoping the clutch will last a bit longer cause delivery takes 1 month + for them this side (Europe).

 

[nota4re]

Ford GT clutches driven properly will last a LONG time - prob 100K miles or more. BUT - the life will be CONSIDERABLY shortened with abuse. Abuse may or may not be intentional. I think that by far the most common "abuse" is when new-to-GT drivers inadvertently start out in 3rd gear instead of first and they have to slip the clutch a lot to get the car rolling. In my experience, this is all too common with transport drivers and is exacerbated when they have to drive up a ramp or incline. First gear in the GT is a little abnormal insofar that the gear shift lever is leaned over toward the driver. Intuitively, it feels more natural to have the gear lever straight up and down which is first gear for many cars but 3rd gear for the GT. This is the only bit of instruction I give to newbie drivers of the GT because everything else is so attractively normal about the driving experience.

Regarding HP limits, the OEM clutch simply runs out of clamping force above 850HP or so. We built a couple of twin turbos back in the day where the owner opted to leave the OEM clutch. All was good until they did a couple of passes at a mile venue where ALL available HP is applied at WOT over 10's of seconds. A few of those passes and the clutch is the weak link. I remember well the first time Terry Carlson drove his car at the Mojave Mile event. We had instrumented the heck out of that car so we could keep everything safe. (We dyno'd that car at 1017 RWPH). Anyway, in reviewing the datalogs after the second pass, our first conclusion was that we were having significant clutch slippage with the engagement of 3rd gear. But, we looked a bit further and determined that it was wheel spin. Unbelievable! You all know how tall 3rd gear is and the car is hunkered down real good by that point in the run... and it lights the tires? That's a shitload of torque! Terry's car had the SPEC clutch that survived all of the mile passes but the OEM clutch would undoubtedly start slipping under the same conditions.

 

[white out]

Spec is a love/hate brand, there doesn't seem to be much in between. Not FGT related, but there are many documented builds where Spec did not hold up to their competition and in some instances OEM clutches. Definitely do your research before going that route. . . But the lighter flywheel and pricing is very tempting.

 

[Specracer]

I think we need a thread merge.

 

[Daniel_Iaciu]

Ford GT clutches driven properly will last a LONG time - prob 100K miles or more. BUT - the life will be CONSIDERABLY shortened with abuse. Abuse may or may not be intentional. I think that by far the most common "abuse" is when new-to-GT drivers inadvertently start out in 3rd gear instead of first and they have to slip the clutch a lot to get the car rolling. In my experience, this is all too common with transport drivers and is exacerbated when they have to drive up a ramp or incline. First gear in the GT is a little abnormal insofar that the gear shift lever is leaned over toward the driver. Intuitively, it feels more natural to have the gear lever straight up and down which is first gear for many cars but 3rd gear for the GT. This is the only bit of instruction I give to newbie drivers of the GT because everything else is so attractively normal about the driving experience.

Regarding HP limits, the OEM clutch simply runs out of clamping force above 850HP or so. We built a couple of twin turbos back in the day where the owner opted to leave the OEM clutch. All was good until they did a couple of passes at a mile venue where ALL available HP is applied at WOT over 10's of seconds. A few of those passes and the clutch is the weak link. I remember well the first time Terry Carlson drove his car at the Mojave Mile event. We had instrumented the heck out of that car so we could keep everything safe. (We dyno'd that car at 1017 RWPH). Anyway, in reviewing the datalogs after the second pass, our first conclusion was that we were having significant clutch slippage with the engagement of 3rd gear. But, we looked a bit further and determined that it was wheel spin. Unbelievable! You all know how tall 3rd gear is and the car is hunkered down real good by that point in the run... and it lights the tires? That's a shitload of torque! Terry's car had the SPEC clutch that survived all of the mile passes but the OEM clutch would undoubtedly start slipping under the same conditions.

I have gotten to drive my car and will be replacing the clutch soon. I did exactly what you mentioned where I nearly started rolling in 3rd. The clutch fluid unfortunately is black like the cars color, and same for brake fluid )). I'll note all you have said and be very vigilant in the future regarding stock and aftermarket clutches. Currently we pressume car makes 750-800hp cranky but it's not tested or proven, it seems to be the baseline Whipple 4.0 + Full exhaust (straight pipe I believe, it's insanely loud) carbon intake, and whatever pulley came with the supercharger kit. Do you think this setup would present issues on stock clutch?

 

[PeteK]

Daniel: Change the clutch and brake fluid now and throughly flush the fluid until it is clear/amber. Do not change the clutch yet. It has many 10,000's more miles/kilometers to go. No need to do anything to the clutch until it actually starts slipping at full power. Unless you just want to spend money needlessly...

 

[mmlcobra]

It still depends on how you drive the car.
I completely agree that you should not change a good component unless it starts to fail.
Changing the clutch is not a "small" job!
Mark

 

[HighHP]

I might also add: When flushing/changing the clutch fluid, the old fluid from the bleed valve to the slave cylinder does not get replaced. Clutch use will slowly mix the new with the old up the fluid line. Sooo.... after awhile flush again, and then repeat again. The fluid will be cleaner each time.

 

[Daniel_Iaciu]

Daniel: Change the clutch and brake fluid now and throughly flush the fluid until it is clear/amber. Do not change the clutch yet. It has many 10,000's more miles/kilometers to go. No need to do anything to the clutch until it actually starts slipping at full power. Unless you just want to spend money needlessly...

I agree. I found clutch and flywheel and bought it for 3k USD flat from the "GT GODFATHER" because I smelled the clutch quiet a bit initially and panicked, but upon inspection it looks good and fluid was basically quiet black (whoever drove this before wasn't kind to it). But I now have the clutch as a backup and won't be swapping it now