Thread: Full face vs Puck questions... long post

Ok So my car went down the other day. Car wouldnt go into gear with the car on but went into gear with the car off. Tried to start it with the car in gear and it would stall out. Took the car apart and we saw the TOB was chilling on the shaft so i figured it was the TOB that cause my problem. Put it together and with the car on the lift and no weight on the car it would go through the gears fine with the car on. But as soon as we put it on the floor, it didnt want to go into gear. Weird right? N e ways we took it apart again and saw the TOB was still in place. We checked the the disk and sure enough a spring was gone... I feel stupid for not checking everything out.

So now we get to my question. After a full out conversation on diffrent options with Greg V Tekkie and James we come into a few disagreements about what disk i should run. Now i have read in alot of diffrent threads that a full face disk will not work with power and will eventually slip and the puck disk will hold alot better for the power. I have looked at many websites and it seems like the street disk always holds less ft/lbs of torque and cost more while the pucks hold more and clost less. Why is this?. Not mentioning any companies but i was told from a good source that most kits come with the exact same PP but just change the disk and price.

So if this is true, are the PP plate rated at what the disk can hold that way you cant go back at the companies saying they are advertising wrong? Im sure that diffrent matariels come into play in the disk no matter if its full face or puck right? If so does that means a disk has a certain torque spec it can hadle when it comes to hp and torque? Or is it all in the PP? Are you paying more for a full face disk for convenience of a smooth ride? My six puck that i had was a jgy sprung disk that was good for 390 ft/lbs of torque yea yea spare me it was free and never used still in the box. It held up great never sliped never had any problems. It felt like stock and was very streetable. It might have even been my fault that it broke aka down shifting at a high speed putting more stress on it????

Teks friend thinks i should go with a street disk but i dont really want 2. James does not want me to go that route either because he went through 3 diffrent full face setups and nuthing held for more then 2 to 3 months. each time he got a diffrent setup it was a stronger setup. He even had a half metal and organic disk and it didnt hold and i know im making more power then him at the moment . Greg says i should just go with a ACT 6 puck set up. Is there a street disk that will hold up to about 300hp? You would think with a Full face disk would hold better because theres more area for the PP to to clamp down so whats the explanation? Im keeping the PP because theres nuthing wrong with it. No heat marks or glazing. I just need a disk. I wouldnt mind going to another 6 puck i just dont want to waste my time going with a street disk if its going to fail on me a couple of months down the line. What do you guys recommend or think would be good. It cant be harsh and it has to be sprung.

Set up is w11 sr20det gtir t28 running at 7 pounds with stock manifold TMIC stage 2 BC cams findaza flywheel 3inch dp calum basic ecu. I dont know what else to put that matters in hp and torque.. Keep in mind that i will be upgrading as money permits. Going front mount and full 3 inch exhaust all the way back because after the CAT its 2.75 and i will be running more boost.

In general, this is true. The more material surface area you have (given the same type of material) the less torque it can hold.

It is a combination of a few things. People are willing to pay more for a better engagement. That bumps the price of the full face discs. Then the full face discs have more material than the pucked discs which costs money. The material on most full face discs could likely cost more as well. It's usually a combination of carbon, fiberglass, and other materials in a complex arrangement. Most pucked clutches are a single, homogeneous material. In addition to that, the full faced street discs have radial and marcel springs which smooth the engagement and make clutch assembly more involved and expensive. All around the full faced discs are more feature-rich and expensive to make and more desirable.


This is a common thing to do, and makes sense from a marketing and economic stand-point. However keep in mind many pressure plates can be modified to create different pressures so having the same PP doesn't mean it's not suited to your needs.

Not exactly sure what you're trying to ask here.

Yes. Like I said above materials on full face clutches tend to be quite different, but even with say a 6-puck clutch disc you can have one from a company that uses one material and one from another company (or even the same company) that uses a different material to give different holding, slipping and longevity characteristics.

Sort of. The disc alone can't have a torque rating. You need to take into account the pressure plate that goes with it. A weak pressure plate will hold less torque than a strong pressure plate given the same clutch disc.

As you've gathered by now, it's not all in the PP either. It's the combination of the two.

Partially, see above.

I don't think we can give a good analysis as to why your specific clutch failed without pictures of the failed unit. However, most will probably assume that if a spring failed, it was due to poor craftsmanship of the disc, not operator error.

Sounds like you're not a candidate for the full faced clutch then. How much torque are you making?

What do you mean by "street" disc?
Also 300 HP is nothing. Is that all we're dealing with here?

Nope it is the exact opposite. I know Physics 101 says there should be no difference, but let me take us to Physics 501 and I'll explain what's going on in my next post.

Sounds reasonable. What type of PP do you have right now?

Again, I'm wondering what a "street" disc is? Anyway, if you're used to the 6-puck and it makes you happy then go with that. Just get an unsprung disc this time so you won't have the same failure.

Oh... Well then... The harshness is not a problem, but why do you demand a sprung disc?


You should not be having the trouble you've been having with clutches. That is not a lot of torque you're making. My guess is 260 WTQ or so and that's being generous. You should not be ruining clutches.

This does change things obviously. It's possible to make maybe 350 WTQ out of that turbo so maybe use that as your upper limit. Still that's nothing hard to obtain in a clutch. Really. No big deal.

Physics 101: The Normal Force
The first force you should know about is what is called the normal force. It is called that because it acts perpendicular to the plane of the surface. In vector math this is called the "normal" direction.
This is the force that acts on objects and keeps them from passing through each other, or keeps atoms from passing through each other. When you put a book on a table gravity pushes the book down but the normal force pushes the book up. If these forces equal, the book rests on the table.

This force is a force between the atoms in the object and is electromagnetic in nature. This is a very strong force which basically only atom smashers and black holes can overcome.

This force acts perfectly perpendicular to surfaces and won't cause objects to move one way or another, it merely keeps them from passing through each other.


Physics 101: Friction Basics

We've all been taught that if you have a smooth, rectangular, 500 gram block of steel placed onto a smooth table top surface there is a force preventing the block from sliding around on the table. This is called friction. Friction is a relatively weak force, so it can be overcome quite easily by pushing on the side of the block. You might notice that the amount of force it takes to start moving the block is more than required to keep the block sliding once it has begun to move.
This brings up the concept of static and sliding friction. Static friction is always stronger than sliding friction. The amount of force required to start the block sliding and "break" the initial bond of friction is more than the amount required to keep the block sliding.

Wrap a string around the metal block and attach it to a Newton meter and pull on the block. You will see that you have to pull on the block with a certain amount of force (Newtons) before it begins moving. Let's say that's 10 Newtons.
Now once the block has begun sliding, slide it slowly and see how much force that takes. Let's say that's 7 Newtons.

Now this whole time we've been sliding the 500g block with it's longer side against the table. Take the block and turn it on it's end so it is standing up taller. Put the string around it and do the same pulling experiments.

You will find the static friction stays at 10 Newtons, and the sliding friction stays at 7 newtons even though the amount of surface area between the block and the table has decreased significantly!
The force of friction is independent of the surface area between the two materials and is completely dependent on the composition of the two materials (coefficient of friction between the two materials) and the amount of force pushing the two materials together (in our experiment that is gravity acting on the mass of the block).

Put weights on the block and watch the force required to slide it rise.

Use a wooden block of the same weight and watch the amount of force required to slide it change (because the materials have changed).



Inevitably a car enthusiast in the classroom will raise their hand and ask the teacher, if this is true, then that means wider tires on cars don't give better grip!?
Depending on the teacher, you will get various answers to this question. The answer is that they aren't paid enough to teach you the complicated physics, so you're getting the watered down, theoretical "Newtonian" physics and you'll have to wait for college (and grad school) to go any further and explain the tire example.




In the next post we will go to college.

Originally Posted by jen36
So if this is true, are the PP plate rated at what the disk can hold that way you cant go back at the companies saying they are advertising wrong?

Not exactly sure what you're trying to ask here.
meaning if they use the same PP for all kits then instead of saying this PP hold 450 torque but the disk cannot hold up to that ammount do they purposely lower the torque rating via what disk comes with the kit...

Originally Posted by jen36
Greg says i should just go with a ACT 6 puck set up. Is there a street disk that will hold up to about 300hp?

What do you mean by "street" disc?
Also 300 HP is nothing. Is that all we're dealing with here?
Street disk meaning full face. As far as i can tell all street disk seem to be listed with a full face disk as a race/drag usually listed next to puck style disk..Also i dont belive my car is making 300hp. Its just a number i belive im going to get very close 2 with minor upgrades and upping the boost levels.

Originally Posted by jen36
You would think with a Full face disk would hold better because theres more area for the PP to to clamp down so whats the explanation?

Nope it is the exact opposite. I know Physics 101 says there should be no difference, but let me take us to Physics 501 and I'll explain what's going on in my next post.

please explain when you have time


Originally Posted by jen36
Im keeping the PP because theres nuthing wrong with it. No heat marks or glazing. I just need a disk.

Sounds reasonable. What type of PP do you have right now?
The PP im using is the jgy(most likely rebage unit) peice thats suppose to be good for 390ft/lbs of torque which i know i will never get. And as i said before nuthing is wrong with it.

Originally Posted by jen36
I wouldnt mind going to another 6 puck i just dont want to waste my time going with a street disk if its going to fail on me a couple of months down the line. What do you guys recommend or think would be good.

Again, I'm wondering what a "street" disc is? Anyway, if you're used to the 6-puck and it makes you happy then go with that. Just get an unsprung disc this time so you won't have the same failure.
i want a sprung disk because i herd its way smoother then a unsprung disk with better engagement. Its not as sudden and you can slip it alittle vs a unsprung. Also doesnt a unsprung disk treats the tranny a little harsher then a sprung?.. true? false?

Originally Posted by jen36
It cant be harsh and it has to be sprung.

Oh... Well then... The harshness is not problem, but why do you demand a sprung disc?
read above.....

Originally Posted by jen36
Set up is w11 sr20det gtir t28 running at 7 pounds with stock manifold TMIC stage 2 BC cams findaza flywheel 3inch dp calum basic ecu. I dont know what else to put that matters in hp and torque..

You should not be having the trouble you've been having with clutches. That is not a lot of torque you're making. My guess is 260 WTQ or so and that's being generous. You should not be ruining clutches.

correct which tells me it was just poor quality.....

Originally Posted by jen36
Keep in mind that i will be upgrading as money permits. Going front mount and full 3 inch exhaust all the way back because after the CAT its 2.75 and i will be running more boost.

This does change things obviously. It's possible to make maybe 350 WTQ out of that turbo so maybe use that as your upper limit. Still that's nothing hard to obtain in a clutch. Really. No big deal.

yeah your right. But still i belive my PP of 390ft/lbs should be enough to do me over. I dont want anything crazy in hp. I bearly have traction as it is with my setup lol. I just need the right disk that will hold my power and not fail. Thanks for the answers Ben

lol dude you are nuts. I havnt had something like that broken down in that form in years. It felt like i was reading a text book

Physics 501: Advanced Friction

Hey kids, remember in high school or freshman year when you were taught that the force of friction between two objects was independent of the surface area between them?
Yah, that was a load of crap.

That holds mostly true for very flat surfaces like glass or polished metals and polished marble or slate lab tables.

In the real world where surfaces aren't perfectly flat, there are microscopic factors going on.

Keep in mind that friction is still not completely understood in the world of physics, so if something doesn't make complete sense to you or it seems there are gaps in the knowledge that I'm teaching you then you should go and take that for a senior thesis.

This is so far physicists' best guess as to why materials behave the way they do when pressed against each other. Don't come crying to me if it's not perfect.




So, if materials were perfectly flat, things probably would work as you were taught in the past. Materials however are not perfectly flat, and if you look at even the smoothest of them under a microscope you will find their edges look like saw teeth.
Here's a sharpened knife edge under a microscope.


The saw teeth from one material interlock with the saw teeth of the opposite material and create a situation where when something attempts to slide the materials across each other there end up being many many sites where normal forces act upon the materials causing a greater than expected resistance to movement.

Now you must be thinking that the more surface area between the materials there is, the more saw tooth interlocking there is and the harder it is to slide the materials across one another!

This, however, is not the case. The exact opposite is true in fact. I'll tell you why.

Given the same weight, an object only has so much force it can apply to another surface. If we take the 500g metal block example from Physics 101 and place the metal block with the long side against the table the weight is distributed evenly across a large swath of 3-dimensional saw teeth basically like sand paper. Each interlocking piece will resist movement and have tiny little sites where normal forces resist the sliding motion. Each little site where we have normal forces acting has a portion of the weight of the object acting on it. If there are 500 such sites in this example then each site will have 1 gram acting on it. If the block is stood up on it's end then maybe we have 50 sites where normal forces are acting. Those 50 sites will each have 10 grams acting on them.

Believe it or not, 50 points of contact with 10 grams acting on each is a stronger bond then 500 points of contact with 1 gram acting on each point. This is sort of the leap of faith you have to accept if you're going to understand higher level friction. It makes sense to me, and hopefully it will make sense to you. It is sort of like snow shoes and how they work. If you spread the weight out over a larger surface area you won't have such deep interlocking of the materials and it will take less force to move them across each other.

It might help to imagine 50 lbs. placed on a stainless steel sewing needle with the needle supporting the entire weight and pointing down onto a marble table. If you tried to slide the needle along the table you would have a MUCH harder time than if you had a giant stainless steel baking tray with 50 lbs. of sand in it and tried to slide that across the table.

In layman's terms, with less points to spread around the weight of the object, the saw teeth dig in better and can get a better hold. It's actually similar to what happens with rally cars on snow. Rally cars equip tires with metal spikes on them to dig into the snow, but they run very thin tires in the snow so there are only a few spikes carrying the weight of the vehicle. Those few spikes drive deeper into the snow than they would if there were more of them, giving them better grip.



Have you followed along so far?
Great!


Now I know what you're going to ask, especially since I brought up tires again.
If you've just finished telling us that the less surface area between the two materials the higher the force of friction will be, then why the hell do wider tires give more grip on dry pavement?!

That's a question for "Physics 701: Friction Between Non-solid Surfaces". Maybe I'll hit on that next.

It's all true, yes. Especially the last part.

yeah. its hard enough to find a good tranny now or days so i think i will stick with the sprung 6 puck 7and make the tranny last a little longer...

Physics 701: Friction Between Non-solid Surfaces

"I've sat through 5 years of physics and everything I've learned tells me that wider tires won't give a car more traction. Either that, or they actually make traction worse. However, I know that is not the case because if it were, drag racers would use the thinnest tires they could find."



It's simple really, and it's not even microscopic. The simple truth is that the typical rules of friction apply to solid objects of uniform construction and relatively flat surfaces. Once you get into "sticky" materials or materials that can change their shape like rubber can, all bets are off.

Firstly, rubber is "sticky" and has an adhesive quality that aids in traction. The more of this touching the ground, the better.

Also rubber deforms and matches the shape of the road surface (which is anything but flat) and the rubber uses the imperfections in the road to "hold onto". The more rubber you have on the road the more imperfections in the road the tire can hold onto.

Why are good drag strips as smooth as possible if imperfections aid in grip?
Simple again.
Good drag strips have smooth tracks to provide racers with a surface that won't chew up their tires. Think about it. There is so much (nonuniform) traction with rough surfaces that rubber is torn from the tire.
Good drag strips have smooth tracks to create predictable, safe launches. (See above)
Good drag strips have smooth tracks to allow the traction compound they use give the maximum benefit.

Man that was a whole lot of reading...

Jen - YOU DON'T DRIVE A TRACK BEAST. You daily drive that bitch. Full face street/strip disc with your pressure plate is MORE than sufficient. Matter of factly, I'M going back to an organic disc from ACT. I'm keeping the XTSS Pressure plate, though. I don't track mine every day, either.

You go ahead and choose whatever you would like, I'm just giving you advice from my guy that has been tracking imports for over 15 years Honda's are making over 500whp and 400wtq with full face setups. Granted their trannies are a little tighter than ours, clamping force is clamping force, no way around it.

I've given you the prices for all selections available to be drop shipped from the east coast, so you let me know what you want to do and we'll make it happen.