[HHGadget]

I understand they should have a markup over the parts prices and probably are also adding a larger margin to cover any eventual "development costs" such as maybe some testing to see what worked best. And some profit for that "work" plus keeping the item listed and on stock etc.


That I agree with, and maybe you should get on the phone with Clutch Masters to solve any doubts you have before you install the kit and risk not being able to get a refund because clutches are wear items. If you do not feel confident about their response, or realise you're not going to be covered by a good healthy warranty policy, you might as well just return the kit right away.


I was going to suggest their name, or Exedy, but only on the basis of being famous as I never tried any of their products. But aren't them the guys that can make a custom clutch for you if your car is not on catalog? Maybe you could specify target HP and torque and have them work out a solution for you. Might be expensive but might be worth the price of having a working and failsafe design. And you might talk them into reducing the price if you can cobble up a group buy at the forum for, say, 5 units at least? Plus they will be able to have it on catalog from then on.

Plenty of Spec history here on the forums but pretty consistent complaints about chatter and (obviously) being more race orientated. That’s why the DDM one sounded good. He claimed a happy medium and that would have been great with me if it worked.

honestly if I wanted an OEM pressure plate I would have ordered a GM branded one for the warranty alone. The real question is how do you take an OEM pressure plate and rate it for 150 more horsepower?

i will say the Clutchmasters flywheel seems nice and well built.

 

[kgschlosser]

@HHGadget

If I get m a couple of measurements from the clutch disc I can tell you what would be needed in clamping force for your application. I can also give you an approximate on what the OE pressure plate clamping for is. an using that number I can tell you what the estimated theoretical torque rating would be for the new clutch

center of disc to outside edge of friction material
center of disc to inside edge of friction material

I also need the distance between the friction measured on the outside and inside as well.

I need those 4 numbers and I can do some math and we can see what would be needed and what the new clutch is.

 

[kgschlosser]

I think I found the LUK part number for the pressure plate.

Here are the part numbers that I found.

Pressure Plate: 124 0407 10
Clutch disc: 324 0430 10
Dual Mass Flywheel: 415 0318 10
Flywheel Bolts: 411 0159 10
Clutch Slave: 510 0230 10

Unfortunately they do not give any specifications other then the diameter being 240mm

 

[JohnWR]

Plenty of Spec history here on the forums but pretty consistent complaints about chatter and (obviously) being more race orientated. That’s why the DDM one sounded good. He claimed a happy medium and that would have been great with me if it worked.

honestly if I wanted an OEM pressure plate I would have ordered a GM branded one for the warranty alone. The real question is how do you take an OEM pressure plate and rate it for 150 more horsepower?

i will say the Clutchmasters flywheel seems nice and well built.

You need some way to compare the clamping force of the OE and CM pressure plates.

 

[lorennerol]

You need some way to compare the clamping force of the OE and CM pressure plates.

If they have the exact same manufacturer and part number, I think it's incumbent on the supplier to explain how they are not the same. I'd certainly expect that before I attempted to measure spring pressure. A coat of white paint is hardly worth $500.

 

[JohnWR]

If they have the exact same manufacturer and part number, I think it's incumbent on the supplier to explain how they are not the same. I'd certainly expect that before I attempted to measure spring pressure. A coat of white paint is hardly worth $500.

The stamping could be the identification for the shell. Since the fingers have the same numbers as the stock, the difference would have to be the spring rating. The only way to know if it is different is to compare forces. Anything else is speculation.

 

[lorennerol]

The only way to know if it is different is to compare forces. Anything else is speculation.

I don't see how comparing springs from a 13 year old clutch to springs from a new clutch is a way to tell. Springs age through creep and relaxation.

I also don't see how asking the supplier to explain the difference is considered "speculation".

What is speculation is positing that they removed the springs from a new pressure plate and replaced them with different springs, then didn't state this in any way.

 

[HHGadget]

Spring rating would be the thickness and type of the material, pivot point and number of fingers (width of metal on finger) would all play into it. Which are also identical (except the pivot point as per below). Of course age and wear would factor as Lorenerol states above. I believe John was specifically answering my question of "how can you tell"..
Regardless, let the intellectual speculation end.

News Flash!

Actually I just got off the phone with them and they are saying they move the pivot point in the OEM pressure plate and that is where they "work their magic".
Not sure how to see that physically but i will take a deeper look with a flashlight and reading glasses (getting old) on both pressure plates. I have no reason to doubt them but am curious. He said you can see the welding they have done to accomplish this...

Fascinating. Additionally they say the kit is plug and play and has no need for shims (this would make sense as their single mass aluminum Flywheel is as large as the OEM Dual Mass, just significantly lighter). He couldn't explain why the sales person i spoke to mentioned that it did come with shims, other than he may have not been knowledgeable about the specifics of this model clutch kit.

FWIW, I did read this about moving the pivot point:
"Moving the pivot point can add more clamping force but the clutch’s holding power over time may decrease rapidly due to clutch wear. Finally, clutch release problems may be introduced when the pivot point is modified."

I think I am going to suck it up and install this clutch. I am impressed with the workmanship on the flywheel, though I am wondering about longevity of the pressure plate / clutch disk and I dont know how I could prove or disprove that. Since this is a wear item and driving styles differ so wildly, though i have found posts on other forums for other cars where a clutchmasters clutch wore out prematurely, the same can be said for almost any brand.

The friction surface on this new flywheel is serviceable (bolted, not riveted) so that speaks to longevity in my book. If the flywheel can last, and I run through friction plates, that is not a lot different than brake pads and I can live with that.

Will be looking under the skirt of the pressure plate when i get home. If i can verify they did move the pivot point, what the hell? Gonna give it a shot

 

[kgschlosser]

There is a way to reset the spring and set it to a higher amount of force. This process has been patented and I do not know who owns that patent. From my understanding it is a pretty involved process to do.

I spent last night educating myself on how a clutch is designed and the math behind it. The OE disc is a full face disc. The clutch material makes a 360° path around the disc. A puck disc has segments of friction material usually in 6 sections or 4 sections. A puck disc will be able to hold a higher amount of torque with the same clamping force as a full face disc. It comes at a cost tho. reduced life. @HHGadget ordered a full face disc and that is not exactly what he got. While the metal disc it's self is a full face the friction material is not.

 

[HHGadget]

@HHGadget ordered a full face disc and that is not exactly what he got. While the metal disc it's self is a full face the friction material is not.

I did order the "D" version of this clutch (D = Daily Driver in Clutchmasters speak). The "R" version comes with a segregated puck and I believe is unsprung, though you would want to call them to check for sure.

 

[kgschlosser]

You are right about the model numbers. But actually look at your clutch disc. While the metal disc is solid and not like a "puck" disc the friction material is not. The friction material is about 1/2 of what the OE clutch is. That being done is going to increase the contact pressure at the friction material by almost double what the OE is. Downside is the clutch is going to last 1/2 as long as the OE clutch would. If you wanted a long lasting clutch capable of holding you would have to have the clamping force of the pressure plate increased by close to double what it is.

Did you ask them what the clamping force is of the modified pressure plate? If I know that and the measurements I asked for in a previous post I can tell you what the theoretical torque rating is going to be.

 

[HHGadget]

You are right about the model numbers. But actually look at your clutch disc. While the metal disc is solid and not like a "puck" disc the friction material is not. The friction material is about 1/2 of what the OE clutch is. That being done is going to increase the contact pressure at the friction material by almost double what the OE is. Downside is the clutch is going to last 1/2 as long as the OE clutch would. If you wanted a long lasting clutch capable of holding you would have to have the clamping force of the pressure plate increased by close to double what it is.

Did you ask them what the clamping force is of the modified pressure plate? If I know that and the measurements I asked for in a previous post I can tell you what the theoretical torque rating is going to be.

I did not ask. I was satisfied with their answer but now want to verify what i was told. Will post any pictures or questions here if anyone knows "how" to see the pivot point without disassembly, which i have no interest in doing on the new one.

Getting a solid education in clutches though. Probably boring topic for many but fascinating to me.

 

[kgschlosser]

If you want to get into the design I can take you all the way down that rabbit hole. Your brain will be hurting afterwards.

The hard part about the LUK pressure plate and the clamping force is that it's not a constant. You see those additional springs? Those are part of a centrifugal design that increases the clamping force as RPM increases. How effective it is, I couldn't tell ya, I would need to call LUK and ask them.

 

[HHGadget]

If you want to get into the design I can take you all the way down that rabbit hole. Your brain will be hurting afterwards.

The hard part about the LUK pressure plate and the clamping force is that it's not a constant. You see those additional springs? Those are part of a centrifugal design that increases the clamping force as RPM increases. How effective it is, I couldn't tell ya, I would need to call LUK and ask them.

Probably dont want to be in the same room with me if my brain starts hurting. I have enough brain farts as it is

 

[HHGadget]

Without taking them apart, I finally did find a difference between them. Not sure if this bolt is where the pivot point is.

 

[HHGadget]

Did some more online researching. That bolt is one of the straps that connects the cover to the rest of the pressure plate.
Not seeing how i could tell if anything had been done to adjust the pivot point so I am just going to have to take them at their word and install it.
Unfortunately we have been hovering at near 100 degree days here (as I guess most of this country is this week) so hoping for a slight break in the weather to complete the install.
Also, my wife was unhappy i moved this into the kitchen for inspection last night (best light in the house) so i am banished back to the garage

 

[kgschlosser]

I set up my portable garage and if it gets too hot out I can wheel the portable air conditioner out there and fire it up. It works more as a cooled fan as it is only able to lower the temp in the garage maybe a degree or 2 and that's it. but having it as a cooled fan really helps a lot.

 

[HHGadget]

I have a similar setup but when it gets this hot out here a couple degrees is not enough.
Also by the time i get home the garage can be well over a hundred sitting all day.
Plus the lighting is superior in my kitchen
On the "to-do" list is upgrading the electrical panel to support insulating and air conditioning the garage. got other priorities that keep getting in front of that though, like getting my car back up and running and all these car parts put away in the garage so I can actually move in there.

 

[HHGadget]

Ok, after confirming with Clutchmasters over the phone that they move the pivot point on the pressure plate and that combined with the 8 puck disk should get me to the engine torque I need i finally had a couple hours this morning to install the clutch as the car has been sitting on jack stands in my driveway for a couple weeks while I detoured for some of life’s necessities.
The torque spec on the ARP flywheel bolts I bought is slightly different than the OEM bolts.
ARP and Clutchmasters suggest to go with the manual specs so here is what I did.
-First I put a tiny dab of high temp gear grease on the top of my pinky and rubbed it inside the pilot bearing. I then wiped the face of the crank with brake clean on a rag.
-Thoroughly clean the new flywheel and pressure plate friction surfaces with brake clean on a rag. And I mean 3 passes thoroughly.
-finger tight all ARP flywheel bolts in a crosshatch pattern.
-following Clutchmasters instructions, slowly crosshatch pattern them all to 20 ft lbs.
- once done, remove them one at a time and blue loc-tote them, then reinsert and torque back to 20 ft lbs. again in a crosshatch pattern.
-then, following the shop manual, cross hatch a torque rating first pass at 39 ft lbs.
-then a second pass at 25 degrees following the crosshatch pattern.
-then I switched back to torque and gently checked where I was at to confirm I was over the ARP 54 ft lbs rating for these bolts. Generally they were at 56-58 ft lbs.
-then I attached the clamping dial indicator and gently rotated the flywheel. Since I am by myself I had to turn it by the flywheel so there was a little wiggle in the dial caused by me turning at the flywheel. Regardless it passed muster at only a few ticks on the dial either way.
-then I cleaned the friction surfaces again with brake clean
-then I installed the clutch friction disk with the alignment tool.
-then I put the pressure plate on.
-then using a small flathead screwdriver that was as close as I was going to get I made sure the friction plate was centered
-Not called for but I put a small dap of blue loctite in the center of each bolt and slowly tightened the pressure plate bolts to 22 ft lbs, following the tightening pattern in the manual. I took four passes at slowly getting to 22 ft lbs in the pattern as to ensure an even application.

that’s it for today as I am off for my sons 8th birthday and at 10:30 am it is already 80+ degrees (been stupid hot here for more than a week).
Have a great weekend all!

 

[HHGadget]

I am documenting every step here for my own sanity so that if something goes wrong I can back track to make sure I didn’t skip a step or torque something incorrectly.
Sorry for the boring post