Better upgrade/replacement Miata clutch for less then OEM.
#22
so I am guessing this does apply to aftermarket mx6 clutches as well?
random ratings comparison with prices i was seeing on ebay:
f1 stage 1 clutch kit:
1.8 Miata - 227 hp, 204 ft/lbs, $117 shipped
2.5 Mx-6 - 262 hp, 246 ft/lbs $108 shipped
f1 stage 3 clutch kit:
1.8 Miata - 320 hp, 297 ft/lbs $169 shipped
2.5 Mx-6 - 380 hp, 378 ft/lbs $156 shipped
and mx-6 clutch kits seem to be 8% cheaper
random ratings comparison with prices i was seeing on ebay:
f1 stage 1 clutch kit:
1.8 Miata - 227 hp, 204 ft/lbs, $117 shipped
2.5 Mx-6 - 262 hp, 246 ft/lbs $108 shipped
f1 stage 3 clutch kit:
1.8 Miata - 320 hp, 297 ft/lbs $169 shipped
2.5 Mx-6 - 380 hp, 378 ft/lbs $156 shipped
and mx-6 clutch kits seem to be 8% cheaper
#25
I Got a set for MX6 and did some rough measurements on the pressure plate with some weights and a dial gauge. It turned out to have an equal spring rate as the Miata. Also spring geometry measured very similar, apart from the obvious finger length. Both were Exedy/Daikin clutch (DK stampings). I do not see how I could have used the MX6 PP with the Miata TOB which falls right through. Anyway, the larger disc is a nice find!
therieldeal, you seem to be doing some interesting clutch work. I would love to hear the toyota pickup truck disc story.
therieldeal, you seem to be doing some interesting clutch work. I would love to hear the toyota pickup truck disc story.
#26
A word of caution: the MX6 center plate of the disc protrudes about 2mm more towards the pressure plate fingers than the original. Looks like they might even contact when depressing the clutch. I don't want to find out what happens if they do.
Now I'm back to considering using the MX6 pressure plate after all. I'll have to find a larger TOB to contact the fingers properly though. Toyota 1ZZFE engine (1.8 Corolla etc) should have a 33mm TOB bore which is close. Another option would be to sleeve the transmission front cover shaft to take many other bearings (such as Honda Prelude). Sadly the MX6 part I got was too wide for the fork. The seat of the fork pivot ball should also be machined a bit lower to compensate the protruding MX6 fingers.
Now I'm back to considering using the MX6 pressure plate after all. I'll have to find a larger TOB to contact the fingers properly though. Toyota 1ZZFE engine (1.8 Corolla etc) should have a 33mm TOB bore which is close. Another option would be to sleeve the transmission front cover shaft to take many other bearings (such as Honda Prelude). Sadly the MX6 part I got was too wide for the fork. The seat of the fork pivot ball should also be machined a bit lower to compensate the protruding MX6 fingers.
#27
Incorrect.. if you halved the area of the pad but kept the same normal force applied to it, it would work better (discounting heat dissispation/fading). The only two things that matter are force applied and coefficient of friction. Here's a quote from a website that explains this in more detail... all you engineer/physics types need not read further.
"Standard friction equation
When a force is applied to an object, the resistive force of friction acts in the opposite direction, parallel to the surfaces.
The standard equation for determining the resistive force of friction when trying to slide two solid objects together states that the force of friction equals the coefficient friction times the normal force pushing the two objects together. This equation is written as
Fr = μN
where:
•Fr is the resistive force of friction
•μ is the coefficient of friction for the two surfaces (Greek letter "mu")
•N is the normal or perpendicular force pushing the two objects together
•μN is μ times N
Fr and N are measured in units of force, which are pounds or newtons. μ is a number between 0 (zero) and ∞ (infinity).
Applies to static and kinetic
This equation applies to both static and kinetic sliding friction. Static friction is the friction before an object starts to slide. Kinetic friction is the friction when the object is actually moving or sliding.
Static friction and kinetic friction have different coefficient of friction values.
Independent of area for sliding hard surfaces
An interesting result of this equation is that in the case of sliding friction of hard surfaces, the friction is independent of the area of the surfaces. In other words, it is just as difficult to move a 1 square-cm object as a 1 square-meter object, if they both are pressed to the surface with the same amount of force.
This is not intuitive. You would think that there is more friction when the surfaces are larger, but the friction equation states otherwise. You can verify this fact with experiments."
I'd imagine the MX-6 clutch would work better but it would be because of its larger diameter having slightly more mechanical advantage rather than the increase in area.
"Standard friction equation
When a force is applied to an object, the resistive force of friction acts in the opposite direction, parallel to the surfaces.
The standard equation for determining the resistive force of friction when trying to slide two solid objects together states that the force of friction equals the coefficient friction times the normal force pushing the two objects together. This equation is written as
Fr = μN
where:
•Fr is the resistive force of friction
•μ is the coefficient of friction for the two surfaces (Greek letter "mu")
•N is the normal or perpendicular force pushing the two objects together
•μN is μ times N
Fr and N are measured in units of force, which are pounds or newtons. μ is a number between 0 (zero) and ∞ (infinity).
Applies to static and kinetic
This equation applies to both static and kinetic sliding friction. Static friction is the friction before an object starts to slide. Kinetic friction is the friction when the object is actually moving or sliding.
Static friction and kinetic friction have different coefficient of friction values.
Independent of area for sliding hard surfaces
An interesting result of this equation is that in the case of sliding friction of hard surfaces, the friction is independent of the area of the surfaces. In other words, it is just as difficult to move a 1 square-cm object as a 1 square-meter object, if they both are pressed to the surface with the same amount of force.
This is not intuitive. You would think that there is more friction when the surfaces are larger, but the friction equation states otherwise. You can verify this fact with experiments."
I'd imagine the MX-6 clutch would work better but it would be because of its larger diameter having slightly more mechanical advantage rather than the increase in area.
And furthermore, before you go spinning off on me, I'm just ******* with you.
#28
Senior Member
Thread Starter
iTrader: (1)
Join Date: Aug 2006
Location: Illinois
Posts: 1,011
Total Cats: 7
I Got a set for MX6 and did some rough measurements on the pressure plate with some weights and a dial gauge. It turned out to have an equal spring rate as the Miata. Also spring geometry measured very similar, apart from the obvious finger length. Both were Exedy/Daikin clutch (DK stampings). I do not see how I could have used the MX6 PP with the Miata TOB which falls right through. Anyway, the larger disc is a nice find!
therieldeal, you seem to be doing some interesting clutch work. I would love to hear the toyota pickup truck disc story.
therieldeal, you seem to be doing some interesting clutch work. I would love to hear the toyota pickup truck disc story.
#29
Yes, genuine Mazda part. I thought they were the same for both 1.6 and 1.8. However, I see my pressure plate is not the same as yours. There must be a difference in finger length. Mine is manufactured by Daikin clutch and looks more similar to the Miata one. Search ebay for "MZC 543" to see what I mean. What company manufactured yours?
Last edited by j-po; 09-09-2010 at 03:31 AM.
#30
For what it's worth all Clutch kits from NAPA, Autozone and Advance are all made by Perfection Clutch as of right now. Doesn't mean some old stuff isn't in circulation still or some may have outside sources, like independent NAPAs. Napa used to sell Exedy but every big chain is starting to sell the same stuff in different boxes. Quality is going down along with the price on some of this stuff.
#31
Senior Member
Thread Starter
iTrader: (1)
Join Date: Aug 2006
Location: Illinois
Posts: 1,011
Total Cats: 7
For what it's worth all Clutch kits from NAPA, Autozone and Advance are all made by Perfection Clutch as of right now. Doesn't mean some old stuff isn't in circulation still or some may have outside sources, like independent NAPAs. Napa used to sell Exedy but every big chain is starting to sell the same stuff in different boxes. Quality is going down along with the price on some of this stuff.
#32
I have been playing with KL's for years and will be doing the clutch on my 2000 shortly, I am curious to hear if anyone ever went with the MX6/KL Pressure plate and how it worked out.
Having a better disc is nice but if I was going to buy a clutch kit and only use the disc that still leaves the pressure plate as a weak point.
Just curious.
Having a better disc is nice but if I was going to buy a clutch kit and only use the disc that still leaves the pressure plate as a weak point.
Just curious.
#33
Senior Member
Thread Starter
iTrader: (1)
Join Date: Aug 2006
Location: Illinois
Posts: 1,011
Total Cats: 7
I have been playing with KL's for years and will be doing the clutch on my 2000 shortly, I am curious to hear if anyone ever went with the MX6/KL Pressure plate and how it worked out.
Having a better disc is nice but if I was going to buy a clutch kit and only use the disc that still leaves the pressure plate as a weak point.
Just curious.
Having a better disc is nice but if I was going to buy a clutch kit and only use the disc that still leaves the pressure plate as a weak point.
Just curious.
I think the main advantage to the KL clutch set is mainly due to the increaded surface area of the disc. It will stay cooler, last longer, hold more torque, and with less fade based on the surface area. Being larger in diameter also put more friction surface outward from center which can transfer more torque for any given area.
If your trying to upgrade all your weakest links then you will need to upgrade every weak component. That shopping list has no end. This swap is more for the owner who needs a clutch because it is worn and this is a way to get a better performing clutch for less using over the counter parts. It's not necessarily an upgrade for someone wanting the best performance. There are better options out there but they cost significantly more and it wont be in stock.
I did it. It worked. It performed and felt better with much less fade then stock clutch on a turbo Miata. That's all I can say about it.
Hey Cross. Why not just put a KL in the 5. =)
#37
Senior Member
Thread Starter
iTrader: (1)
Join Date: Aug 2006
Location: Illinois
Posts: 1,011
Total Cats: 7
I'm already in love with the KL. The first time I drove the sand rail I thought that motor needed to be in something light and rwd. Then boosted.
#38
No problem. The MX6 clutch disc with its larger diameter center stub and more outwards protruding center metal plate looked like they would not work with the Miata PP and TOB (The center stub of the Miata disc is clearly made thin enough to pass into the TOB). The Miata TOB also would not work with the MX6 PP, it fell right through. So I had to use the larger MX6 TOB which required sleeving the transmission front cover shaft to a larger diameter. Also the more protruding fingers of the MX6 PP and thicker TOB required machining the fork pivot point down as well as extending the cylindrical portion of the transmission front cover further back by machining. Also ground the fork a bit wider to fit the TOB & modified the TOB.
Anyway, parts are ready and look like they will fit now. I have not had time to install them yet. If I had to do it all over again, I wouldn't. I'd just bolt in a performance clutch designed for the Miata. Now of course I can use cheap MX6 replacement parts fairly easily which was my original intention.
How knows, maybe I am wrong about the Miata PP and TOB and they would have fitted after all. I did not feel like trying and failing by having the TOB catching onto the disc center stub or the PP fingers catching onto the disc springs. It would also have been a shame to waste the new PP. Your PP looks different. I assume that may work better. As I said, take your chances.
Anyway, parts are ready and look like they will fit now. I have not had time to install them yet. If I had to do it all over again, I wouldn't. I'd just bolt in a performance clutch designed for the Miata. Now of course I can use cheap MX6 replacement parts fairly easily which was my original intention.
How knows, maybe I am wrong about the Miata PP and TOB and they would have fitted after all. I did not feel like trying and failing by having the TOB catching onto the disc center stub or the PP fingers catching onto the disc springs. It would also have been a shame to waste the new PP. Your PP looks different. I assume that may work better. As I said, take your chances.
#39
Senior Member
Thread Starter
iTrader: (1)
Join Date: Aug 2006
Location: Illinois
Posts: 1,011
Total Cats: 7
Which throwout did you use? 1.6L? All the 1.8L throwouts I had (all the same) contacted the KL PP fingers with no problems. The 1.6L throwout bearing won't make contact with the fingers but the body of the bearing is large enough that it wouldn't 'fall right through'. If the finger opening was large enough for a 1.6L throwout to fall through, the MX6 throwout wouldn't work either. I wish I hadn't thrown out all the parts I had. I could have taken side by side photos of the 3 throwouts. Maybe you don't have a KL PP. Wouldn't be the first time I've seen the wrong clutch parts in the box.
No problem. The MX6 clutch disc with its larger diameter center stub and more outwards protruding center metal plate looked like they would not work with the Miata PP and TOB (The center stub of the Miata disc is clearly made thin enough to pass into the TOB). The Miata TOB also would not work with the MX6 PP, it fell right through. So I had to use the larger MX6 TOB which required sleeving the transmission front cover shaft to a larger diameter. Also the more protruding fingers of the MX6 PP and thicker TOB required machining the fork pivot point down as well as extending the cylindrical portion of the transmission front cover further back by machining. Also ground the fork a bit wider to fit the TOB & modified the TOB.
Anyway, parts are ready and look like they will fit now. I have not had time to install them yet. If I had to do it all over again, I wouldn't. I'd just bolt in a performance clutch designed for the Miata. Now of course I can use cheap MX6 replacement parts fairly easily which was my original intention.
How knows, maybe I am wrong about the Miata PP and TOB and they would have fitted after all. I did not feel like trying and failing by having the TOB catching onto the disc center stub or the PP fingers catching onto the disc springs. It would also have been a shame to waste the new PP. Your PP looks different. I assume that may work better. As I said, take your chances.
Anyway, parts are ready and look like they will fit now. I have not had time to install them yet. If I had to do it all over again, I wouldn't. I'd just bolt in a performance clutch designed for the Miata. Now of course I can use cheap MX6 replacement parts fairly easily which was my original intention.
How knows, maybe I am wrong about the Miata PP and TOB and they would have fitted after all. I did not feel like trying and failing by having the TOB catching onto the disc center stub or the PP fingers catching onto the disc springs. It would also have been a shame to waste the new PP. Your PP looks different. I assume that may work better. As I said, take your chances.
#40
I didn't think anyone could understand I meant the whole body of the bearing fell right through the PP. I should have made that clear. Anyway, I used the MX6 TOB as stated in my previous post.
You are saying 1.6 and 1.8 have different TOBs? The only TOB I can find is Mazda part number B622-16-510 which fits both. Could you please show some evidence there are indeed different TOBs?
Getting the wrong PP crossed my mind too but then again, there are other vendors on ebay showing pictures of the PP I have. Thus I suggested there may be variations of the theme.
Search ebay for MZC 543 to see what you do not want to get.
Even if you managed to get a long finger PP the thicker stub on the disc looks like it may be a problem. There must be a reason why the Miata disc stub is so slender.
You are saying 1.6 and 1.8 have different TOBs? The only TOB I can find is Mazda part number B622-16-510 which fits both. Could you please show some evidence there are indeed different TOBs?
Getting the wrong PP crossed my mind too but then again, there are other vendors on ebay showing pictures of the PP I have. Thus I suggested there may be variations of the theme.
Search ebay for MZC 543 to see what you do not want to get.
Even if you managed to get a long finger PP the thicker stub on the disc looks like it may be a problem. There must be a reason why the Miata disc stub is so slender.