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Tue Apr 22, 2014 6:38 pm

anyone know off the top of their head what KEP said to torque the pressure plate bolts to in a performance application, IIRC it was like 25 or 29 ft/lbs?

Thanks!

Tue Apr 22, 2014 6:41 pm

I torqued mine same as stock on my 2110 - 25fp IIRC.

Tue Apr 22, 2014 6:50 pm

Bolt torque is maximum pressure a bolt can exert within its grade... Application has little to do with it....

If its:

8mm and grade 10.9 its torque is 31 ft-lbs (dry)
8mm and grade 9.8 its torque is 27 ft-lbs (dry)
8mm and grade 8.8 its torque is 25 ft-lbs (dry)

Actual torque can be anywhere from 25% to 50% less if lubricated and depending on type of lubrication.

Torquing beyond rating actually stretches bolt and weakens it...

Dale

Tue Apr 22, 2014 7:14 pm

Dale M is correct. People tend to torque everything higher on a HP engine for no apparent reason. Are higher torques going to pull the pieces closer together?

Clutch bolts torque to 18 ft lbs with 8.8 hardware and wavy washers. I believe the length is either 16 or 20.

Stock was NEVER 25 ft lbs.

Tue Apr 22, 2014 9:42 pm

Yep. I've always torqued them to you 18lb/ft. No idea where I got the number from - have never owned a manual. :roll:

Tue Apr 22, 2014 10:44 pm

Dale M. wrote: Application has little to do with it....

Not true, the torque value depends on the engineering requirements of the joint. The 75% of proof load figures you list are for general use only as a maximum safe value for like materials. It doesn't take into account the properties of the material being fastened nor threaded into either. Torque a steel bolt into aluminum at those levels and you will likely tear out the threads.

Just as an example, an M12 bolt can be dry torqued to 65 ft-lbs for grade 8.8, 93 ft-lbs for 10.9, or 108 ft-lbs for 12.9. Yet the VW torque spec for an M12 crankcase bolt is 25 ft-lbs, an M12 pulley nut is 43 ft-lbs, and an M12 lug bolt is 72 ft-lbs.

Tue Apr 22, 2014 11:31 pm

18 ft-lb, lubed

Wed Apr 23, 2014 8:22 am

jhoefer wrote: Dale M. wrote: Application has little to do with it....

Not true, the torque value depends on the engineering requirements of the joint. The 75% of proof load figures you list are for general use only as a maximum safe value for like materials. It doesn't take into account the properties of the material being fastened nor threaded into either. Torque a steel bolt into aluminum at those levels and you will likely tear out the threads.

Just as an example, an M12 bolt can be dry torqued to 65 ft-lbs for grade 8.8, 93 ft-lbs for 10.9, or 108 ft-lbs for 12.9. Yet the VW torque spec for an M12 crankcase bolt is 25 ft-lbs, an M12 pulley nut is 43 ft-lbs, and an M12 lug bolt is 72 ft-lbs.

I agree when into soft alloys... But in case mentioned above its steel into steel.... I guess I was not to clear in my statement about using engineering specification for bolt application...

I believe people using 18ft-lbs specification on assumption threads are lubricated....Haynes manual in section 0 page 9 give bolt specs as dry values.... Some VW assembly manuals always assume thread are lubricated... Got caught on that one a year or two ago.... Also dry specifications vary from document to document .... Dry specs in Haynes manual are about 15% less than some other sources on max torque values and bolt specs...

Haynes manual section 8 page 1 state 18 ft-lbs for "clutch pressure plate to flywheel bolts"... Would seem bolts are probably grade 8.8 and lubed... Bet nobody ever checks bolt grade on clutch cover, they just grab anything that fits....

Dale

Wed Apr 23, 2014 9:50 am

All, thanks for the feedback.

I'll elobarate a bit further..... When I purchased my KEP plate, it came with a little instruction card and it had some suggested torque values (and recommended 10.9 hardware I believe)

I'm not changing things willy nilly, I am just trying to follow what they recommended.

Wed Apr 23, 2014 9:58 am

theDrew wrote: All, thanks for the feedback.

I'll elobarate a bit further..... When I purchased my KEP plate, it came with a little instruction card and it had some suggested torque values (and recommended 10.9 hardware I believe)

I'm not changing things willy nilly, I am just trying to follow what they recommended.

Go with what they recommend!...

Dale