For quite some time it has been my understanding that the Valeo LTx pressure plate can NOT be made stronger, this is due to the diaphragm spring and overall design. It has also been my understanding that the only way to make higher performance LTx clutches is to use better clutch linings on the clutch disk itself. I know that many people on the board share this understanding.

I decided to call Spec clutch and Clutchnet.com to ask them about their Ltx pressure plates.

Spec informed me that their LTx pressure plates are high clamp and not the same spec as the conventional Valeo. They insisted that they are stronger. Every Spec PP I have seen looked like a conventional Valeo with Blue paint.

Clutchnet.com informed me that their LTx pressure plate has the Valeo diaphragm spring heat treated and the fingers tweaked to provide more clamping power. They told me that their red LTx PP had a force rating of 3220 pounds and would cost $450.00. I am not sure what a stock Valeo measures.

My Local clutch maker stated that the Valeo PP can not be made stronger and was calling BS on the above statements. He said that there was no way to tweak the diaphragm spring or relocate the lever fulcrums like normal pressure plates.

As of now I am still convinced that Spec, Mcleod, Centerforce, Ram, Zoom, Maddog, and everbody else uses the exact same non-upgradeable pressure plate. I base this on internet research but I will confess I have not seen all of the above PP's.

Does anyone have any irrefutable knowledge that the after market clutch manufacturers are able to make the Valeo pressure plate stronger than OEM spec?

Thanks.

 

i can tell you from personal experience what i have seen with the three clutches i had, thats about it.
Stock pp and friction disk looked normal
Slp PP and stock friction disk= Pressure plate had holes drilled into it but looked the same as far as the springs were concerned. The car drove like stock and took off like a stock clutch. Slp claimed 30% more clamping force
Now i have a spec stage 2+. This clutch has a way different friction material but the pressure plate seems to just be a powder coated blue stock pp. This clutch has the same amount of pedal pressure the other two does(compressing the spring) but it grabs a lot harder then the other two, it also chattered like a bitch for 2-3k miles, now it only chatters sometimes. This clutch has harshness to it when you fully let the clutch out and has a noticeable difference then the other two. I would say this is due to the friction plate rather then pressure plate due to the pedal effort being equal between all three. I would say that i agree with the local clutch maker from my experience with clutches.

 

Anyone else?

 

I am also curious...as I need a new pressure plate and clutch, but don't want to spend $350+ for just the pressure plate from McLeod, and would rather buy just the disc from them, and then get a generic parts store kit and toss out the clutch that comes with it and use the McLeod disc in place of it.

So if all pressure plates are the same, I will be a happy man, as it is going to save me a good amount of money!

 

well i to am under the impression all LT1 PP are the same. i did call SPEC and they claim that theirs does have higher clamp than a 'stock" unit but did not say how. mcleod said "nothing can be done with the LT1 PP". ZOOM said "well....(read no)".

I have killed a SPEC 2+ and ZOOM HP both on the starting line (4200 lb car 383/T56) in very low miles 2k-4k mi

....so I call ClutchNet and the owner takes my call. He was very candid about SPEC, Fadenzia, ZOOM, McLeod, etc. in saying they do NOT change anything other than the paint on the PP and are ripping people off by selling a PP at the $ they are for a "stock" one. He did say centerForce does have a modification using their "slideing weight" system (as they do on their DF diaphram clutches) but in his opinion that system is BS and RPM's over 10k would need to happen for that concept to work with any effect. further that system on a "pull" clutch is even less effective.

I responded frankly in saying "so you claim a modification, what is it". They add 3 degree of angle to the diaphram fingers and heat treat that metal up to 3 times. This combined process adds more clamp load which he says you WILL feel in pedal pressure. Further he said I can bring in any LT 1 PP I like and he will measure clamp force of that and then show me the clamp force of their PP. He said I would have to order first since they do not stock "assembled" units given they have over 20,100 clutch PP & disc combos. He did say he would refund ALL of my $ if what he said is not true.

ClutchNet is about a 1 1/2 hr drive for me but I am willing to call him on his offer to see WTF is real.

He did say that by "visual" appearance you can't see any difference but the clamp load test will reveal the difference.

ClutchNet is a family owned business and has been open for 30 years. The owner spoke frankly about other companies and where they get their parts (China) and went into great detail on what/why their "made in the USA" parts are superior. He advised you can have the most aggressive clutch disc material on the planet but if the PP lacks the clamp force to hold it the high HP/TQ ratings of that clutch is considerable effected

While this guy certainly should/would support his companys product vs others he was very candid about the "clutch business".

....so anyone have any other updates since the OP posted this thread??

if this "high clamp" thing does turn to be BS I will most likely just get a disc from them and buy a AutoZone kit to harvest the PP from. From what I have used and what I "see" in the pics on their site the disc construction looks to be better than others I have run.

 

Let us know what you find out, I'm very interested to find out once and for all. A friend of mine spoke with SPEC about this recently, and he was directed to this thread for an answer: https://ls1tech.com/forums/manual-tr...-question.html

If what SPEC says is true, then fine. But I find it hard to swallow the price they want for a clutch kit. Especially when these types of PP are nothing new, hell they've been around since '93...Why in the world are they still so expensive???

FWIW, I've been running a SPEC 3 disc with an O'Reilly PP for the last 2.5 years with no issues. However, the day is coming when it will be time to replace it...so if it is true I can get a stronger PP then I'm in...but if it's not true...I don't don't wanna pay big $ for a stocker that I can get from O'Reilly for alot less $$$.

 

I have taken this post from the thread above and repaired the linked images. If you take the time to read this you will see that we have had this discussion before. At any rate let me know if you have any further questions. Thanks,

"WRD, I am not arguing that we have never used Valeo style covers in the past (in fact on occasions when we have delays in getting the plate that we have made we may still use the Valeo style cover--this is not the norm for us but again remember, all we are talking about is the cover, not the entire plate assmebly). I don't view this as a pissing match or an argument. Though I do feel that you are misguided in your understanding of the workings of clutches and the potential for increased clamp-load. As for taking pictures of what makes our clutches our clutches...this request is like asking the Colonel whats in the secret recipe. Every manufacture has their own methods for increasing clamp-load and most are guarded about the specifics of their modifications.

With this in mind, I am unsure what plate you tested and how you tested it. We use Shepard-Thomason Load Cell machines that are calibrated regularly. Considering you indicate that you have "tested" a number of plates I assume that you know what the stock style assemblies are able to produce in terms of clamp-load. For those of you that do not know this, the stock plate produces ~2600psi. Our assemblies pruduce considerably more. After reading your post I thought..."why not just go put an LT1 plate on the tester and take a picture for the skeptics." That is exactly what I have done.





The plate pictured is no different than any other that we manufacture for the LT1. Nothing "special" or "different" was done to up the numbers. This is what you can expect from our LT1 plate (enough said)!
Let me know if you have any further questions. Thanks!"
Attached Thumbnails

 

Wow this is back from the dead and with some hot sauce to boot. So after dropping the matter years ago and now being what I feel to be, "called out", I will comment again. Maybe you could have been a bit more sensitive with the reply. So here we go.

My clutch maker does not have a fitty million dollar Shepard-Thomason Load Cell machine with red digital readout. He has a makeshift POS, hill-jacked, leverage measurement system constructed from misc. stuff and used pinball machine parts that is capable of getting an "in the ball park" reading of the force generated by a pressure plate. If you want I can sketch it out on a cocktail napkin.

When he measured the SPEC PP, the Auto zone PP and my drilled SLP plate, they were all within 2% of each other. All three were set up the same way on the same POS measurement system that I illustrated above. I would be foolish to assume that the numbers provided were dead nuts accurate as what is being shown in the above photo but I do recall them being in the neighborhood of 2500 PSI. Needless to say all three were essentially the same in terms of force produced and the SPEC plate was not producing anywhere near what you claim above.

Now with that said, the SPEC plate could have been damaged, worn or any number of things. It was used but so was the SLP plate. The Auto zone plate was new.

I then disassembled the SPEC plate and the OEM LT4 pressure plate for knowledge in order to begin the discussion on this board and saw absolutely no difference in the cases, the diaphragm springs, pressure surface or the fulcrum points.

SPEC.
I am not calling BS on what you are saying. I will take your word for it but I would still feel more comfortable having an independent source validate the information you provided considering the "simplicity" of the items in question. These were my findings of the three pressure plates in question many years ago and I am sticking to it.

 

WRD...I am sorry you felt my post was less than sensative...I didn't mean to upset you or hurt your feelings. The post I made above is a direct copy of the post I made several years ago when you posed the same basic assertions/questions. Both then and now you seem to be intent on calling us, and other manufactures out with little evidence to support your claim. In fact, I also addressed your testing method in that thread as well:

"WRD, I am glad that I can be of assistance. As a side note the Shepard-Thomason machines that we use can be configured in a way that allows for the testing of both push and pull type assemblies (perhaps the machines that you were referencing were different, perhaps the opperator didn't really know how to use it--no insult intended by these statements). As a point of reference, Load Cells have not really changed much since their inception...they have gotten to be more accurate but the function itself is the same. In the future, I ask that you provide the complete story in regards to your testing procedures as the information you initially provided was simply incorrect and as such was misleading to those that don't know any better. Please let me know if you have any further questions. Thanks and have a great afternoon!"

You never provided any definitive explanation of your measureing techniques or the methods used to acheive your findings...perhaps you have some further support of what you did and how you did it so we can insure that the methods were in fact the same.

I have no idea how old the plate was that you were testing either, and as mentioned in my post above:

" I am not arguing that we have never used Valeo style covers in the past (in fact on occasions when we have delays in getting the plate that we have made we may still use the Valeo style cover"

That being said it is very likely that you did have a Valeo based plate from us--especially if the parts were older.

Oddly enough you seem to feel that you were called out because of my response...yet it seems pretty clear that you were in fact trying to call both our product and the information I have provided, on more than one occasion, into question. I don't ask that you believe me...that's your call (though you seem pretty willing to believe another manufacture). You are welcome to drop by with your plates for a comparative assessment...I'll be happy to help provide information and assistance to you any time. Please let me know if you have any further questions. Thanks,

 

I dont see where I called you out just now. I must have missed it.

Like I said in my last response. I dropped the subject years ago after you posted the detailed and reasonable response you did. I was not going to challenge you any further. I have even posted your response that you provided in countless other threads regarding pressure plates and I have not challenged it since. I am not really challenging it now.

Hell I am running a SPEC 3+ right now and its great for normal driving but slips on race conditions with less than 6K miles.

Again, I am now only posting what I found with the SPEC PP that I had on hand and the other two pressure plates illustrated above due to the manner in which you responded in post #7 after this subject had been dead for so many years.

 

Your original post in this thread is pretty clearly calling both the information I have provided and our parts into question. It looks like you were attemtping to get this stirred up for one reason or another. I am just making sure that misinformation and assumption doesn't mislead others. No harm was intended...I simply stated the facts with pictures to back them up. Again, if you need anything else let me know. Thanks,

 

OMG.
You are posting quotes from years ago. Now who is wanting to stir the pot?

You just made the assertion that I have called you out again, meaning today in the last few posts with the obvious intent of stirring the pot. I DID NOT CALL YOU OUT. GO READ IT AGAIN. I did not call BS or cite another manufactures opinion of SPEC. I only produced my findings from years ago for the sake of discussion. Again, you can post all of the quotes you want, they are several years old.

Dude please move on. Again I said today, TODAY, I am no longer challenging the information you have provided nor have I given it any thought in recent memory. Keep talking if you want. I will keep replying.

Everyone. SPEC's PP is stronger than OEM spec.
Go buy one now.

 

Perhaps perception is the issue...you seem to feel that I was calling you out but I wasn't and I felt like you were making the same assertions again and you say you weren't. I simply wanted to make sure, as I did years ago, that more than assumption and misinformation were present (this isn't specific to your posts alone).

The thread got bumped to the top again and folks were building on what had been mentioned previously. I didn't intend you to take this personally and I apoliogize if you did. Have a good evening!!!

 

Quoted from today:


Maybe I should reevaluate my sense of perception.
Looks like the Jedi mind trick huh.

 

Quoted from today:

The old Jedi Mind Trick huh..."move along now"..."these aren't the droids you're looking for"...now that is some funny stuff. Again...just making sure folks have info from both perspectives. If you get down this way let me know and I will be happy to buy you a beer...as long as you promise not to show up in Star-Wars garb weilding a plastic light-saber!

 

....well I am the one who brought this thread back in what is my frustrating search for a LT1 clutch that will live longer than 5k miles AND give me the street maners AND track ability I would like. My sense is that will be a clutch that does not exist so I will need to pick what priority suits me best and move on with that choice.

I have been communicateing with Jeremy and ClutchNet on the "so how do you modify the PP and what results can you CLEARLY show me">>>

The pics that are now re-posted in this thread from SPEC showing load results were not in it a few days ago when I was in search mode. those pics are very encourageing in showing load.

I have been to ClutchNet who claimed they also make 'adjustments" since they are located within driving distance of where I live. They add that they were the only clutch company doing modification to increase clamp load (which frankly they describe better on their site than SPEC currently does). Again with reservation on believeing any of it (I expect a clutch company representitive to favor their product vs another) I went to see how they do it and did witness them using their pressure test machine (much older than what SPEC has) and their test showed 2345 on a stock PP and 3210 ish on their modified PP. They showed me the process of heating and changeing the angle of the diaphram to do this. They do take a "valeo" clutch, dissamble it, make modification to the diaphram part and reassemble it. they also add another strap on the connection of hat and plate but that is not for clamp force just helps the clutch deal with severe down shifting better as it was explained to me. They also walked me through their shop and showed me how they fabricate the componets for discs which IMHO were very well thought out and made. they claim they do not use "China" stuff as 'other' companies do. The ZOOM PP says 'made in china" on the hub and ClutchNet said the entire hub on that disc was a $2 part (compared to theirs and SPEC it is a POS)

So now there are at least 2 companies making what I would assume are very similar modifications. I can say the ZOOM PP did measure the same as stock FWIW which was 2345 on their machine.