GMPP LSJ Clutch Upgrade For LNF
12-29-2014, 07:22 PM
#52
This is a fun thread....it's different...it's the same...you shouldn't resurface....it's fine if you do it right...why take the risk...why waste the money...ah, the great fun of having no data.
Even the pictures of the clutches are inconclusive (other than LSJ being clearly different). The springs on the GMPP are a different color, but of course that doesn't prove anything and the two (LNF and GMPP) disks are reversed so you can't compare the structure. The pressure plates look similar, and who knows if the different color is just due to different photographers/lighting.
CED is a great supporter of this site, but even their comments are confusing. Are we to believe that having different disks is not important? The entire aftermarket world spends a lot of money trying to convince us their disk is magical and will out perform all others. In fact it's basically the only thing that is tune-able in clutch design other than the load generated by the pressure plate. It is what will largely impact coefficient of friction given the pressure plate and flywheel are steel (ignoring exotic carbon clutches). The coefficient of friction is sort of critical....just a tiny (read: really big) bit important.
and, end rant....
Daniel
Even the pictures of the clutches are inconclusive (other than LSJ being clearly different). The springs on the GMPP are a different color, but of course that doesn't prove anything and the two (LNF and GMPP) disks are reversed so you can't compare the structure. The pressure plates look similar, and who knows if the different color is just due to different photographers/lighting.
CED is a great supporter of this site, but even their comments are confusing. Are we to believe that having different disks is not important? The entire aftermarket world spends a lot of money trying to convince us their disk is magical and will out perform all others. In fact it's basically the only thing that is tune-able in clutch design other than the load generated by the pressure plate. It is what will largely impact coefficient of friction given the pressure plate and flywheel are steel (ignoring exotic carbon clutches). The coefficient of friction is sort of critical....just a tiny (read: really big) bit important.
and, end rant....
Daniel
12-30-2014, 03:15 AM
#53
Senior Member
This is a fun thread....it's different...it's the same...you shouldn't resurface....it's fine if you do it right...why take the risk...why waste the money...ah, the great fun of having no data.
Even the pictures of the clutches are inconclusive (other than LSJ being clearly different). The springs on the GMPP are a different color, but of course that doesn't prove anything and the two (LNF and GMPP) disks are reversed so you can't compare the structure. The pressure plates look similar, and who knows if the different color is just due to different photographers/lighting.
CED is a great supporter of this site, but even their comments are confusing. Are we to believe that having different disks is not important? The entire aftermarket world spends a lot of money trying to convince us their disk is magical and will out perform all others. In fact it's basically the only thing that is tune-able in clutch design other than the load generated by the pressure plate. It is what will largely impact coefficient of friction given the pressure plate and flywheel are steel (ignoring exotic carbon clutches). The coefficient of friction is sort of critical....just a tiny (read: really big) bit important.
and, end rant....
Daniel
Even the pictures of the clutches are inconclusive (other than LSJ being clearly different). The springs on the GMPP are a different color, but of course that doesn't prove anything and the two (LNF and GMPP) disks are reversed so you can't compare the structure. The pressure plates look similar, and who knows if the different color is just due to different photographers/lighting.
CED is a great supporter of this site, but even their comments are confusing. Are we to believe that having different disks is not important? The entire aftermarket world spends a lot of money trying to convince us their disk is magical and will out perform all others. In fact it's basically the only thing that is tune-able in clutch design other than the load generated by the pressure plate. It is what will largely impact coefficient of friction given the pressure plate and flywheel are steel (ignoring exotic carbon clutches). The coefficient of friction is sort of critical....just a tiny (read: really big) bit important.
and, end rant....
Daniel
01-22-2015, 09:29 AM
#55
Platinum Member
Platinum Member
I've never seen a gmpp clutch slip on a LNF, even on turbo swapped cars. It's a surprisingly solid clutch, up to a certain point of course.
01-22-2015, 12:48 PM
#56
Do not use the 19212712 for the LNF, just order the correct LNF clutch, its just as strong
My stocker is about 45k miles and it's slipping on 3rd and 4th gear pulls
Could the issue be that it has been poorly driven by the previous owner...or is the GMPP really stronger than the LNF...still confused.
01-22-2015, 12:58 PM
#57
Senior Member
iTrader: (6)
Ive just received a mail by Tom from CED...
Do not use the 19212712 for the LNF, just order the correct LNF clutch, its just as strong
My stocker is about 45k miles and it's slipping on 3rd and 4th gear pulls
Could the issue be that it has been poorly driven by the previous owner...or is the GMPP really stronger than the LNF...still confused.
Do not use the 19212712 for the LNF, just order the correct LNF clutch, its just as strong
My stocker is about 45k miles and it's slipping on 3rd and 4th gear pulls
Could the issue be that it has been poorly driven by the previous owner...or is the GMPP really stronger than the LNF...still confused.
01-22-2015, 01:29 PM
#58
Senior Member
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Ive just received a mail by Tom from CED...
Do not use the 19212712 for the LNF, just order the correct LNF clutch, its just as strong
My stocker is about 45k miles and it's slipping on 3rd and 4th gear pulls
Could the issue be that it has been poorly driven by the previous owner...or is the GMPP really stronger than the LNF...still confused.
If you think about it we have the second transfer different gears, doesn't change the clutch just because we have different gears.
Also Tom says don't use the gmpp with lnf cause the clutch will not be covered under warranty if installed on an lnf.
01-22-2015, 03:31 PM
#60
The gmpp clutch doesn't need a traditional break in period. Not a bad idea to take it easy on it for a while, but you don't have to for 500 miles like aftermarket clutches
Also, rock auto sells shim kits for the flywheel. Never heard of anyone using one, but they have a .025" and a .05". That'd allow you to reuse the stock flywheel if whoever you had resurface it kept up with how much they took off
Also, rock auto sells shim kits for the flywheel. Never heard of anyone using one, but they have a .025" and a .05". That'd allow you to reuse the stock flywheel if whoever you had resurface it kept up with how much they took off
01-22-2015, 05:44 PM
#61
The gmpp clutch doesn't need a traditional break in period. Not a bad idea to take it easy on it for a while, but you don't have to for 500 miles like aftermarket clutches
Also, rock auto sells shim kits for the flywheel. Never heard of anyone using one, but they have a .025" and a .05". That'd allow you to reuse the stock flywheel if whoever you had resurface it kept up with how much they took off
Also, rock auto sells shim kits for the flywheel. Never heard of anyone using one, but they have a .025" and a .05". That'd allow you to reuse the stock flywheel if whoever you had resurface it kept up with how much they took off
Thanks for the info on the break in!
01-22-2015, 07:26 PM
#63
Platinum Member
Platinum Member
The GMPP clutch is NOT simply a stock lnf clutch.... period.
The pressure plates are indeed different and so is the disc material.
Also, for anyone who's curious. Don't waste your money on buying a LNF flywheel from crateenginedepot. Simply buy a LSJ flywheel.
The pressure plates are indeed different and so is the disc material.
Also, for anyone who's curious. Don't waste your money on buying a LNF flywheel from crateenginedepot. Simply buy a LSJ flywheel.
01-22-2015, 08:45 PM
#65
Senior Member
Hmm, what notable differences have you found between gmpp and stock lnf pressure plates?
01-22-2015, 09:07 PM
#67
Platinum Member
Platinum Member
The gmpp pressure plate is heavier than the lnf and I'll have to dig up exactly what the differences in the makeup of the disc materials are again. They are different though, unless GM has suddenly changed something, but I sort of doubt that one.
01-23-2015, 02:22 AM
#69
Senior Member
I was under the impression that the Sachs pressure plates we use for lnf and gmpp is pretty much universal for Ecotecs with f35 and f40 flywheels( yes the pressure plates will even fit and and function on the F40 dual mass flywheel) Based on the pictures of both pressure plates, they look the exact same, and because of this, one can only assume that if there is any difference it would be the pound rating. Unless the friction disc on the pressure plate is of different hardness? The overall weight difference is interesting...
Last edited by LNFwagonSS; 01-23-2015 at 03:13 AM.
01-23-2015, 10:48 AM
#71
Platinum Member
Platinum Member
The pressure plates physically LOOK the same, but then again so do all of the F35 pressure plates across the board. Pretty much all aftermarket companies who make a clutch setup for the cobalt all use a Sachs pp, however the internal the spring rates and counter weights are what make the difference. For example, even South Bend's strongest clutch (stage 4+) with a 2300lb clamping force rating uses a Sach's pp. Take off the orange coating and it would look exactly the same as the stock lnf pp at a quick glance. Just look at the numbers on the plates. They're stamped differently depending on pressure ratings.
06-12-2017, 10:09 PM
#74
The main reason why CED says not to use this with the lnf is warranty. If you have any problems at all with the clutch, TOB, or clutch pipe it will not be warrantied if used on an LNF. Tom said this is what happens when installed by a dealership. I think that page also says warranty will be void if not installed by dealership.
That said, only other thing you would need is new flywheel bolts, and make sure pressure plate is centered when installed.
That said, only other thing you would need is new flywheel bolts, and make sure pressure plate is centered when installed.
