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There's no topic for clutches yet, so I'll start a one with pics.




The plan is to use one disk at the time. Another on the pic is just a spare. The pressure plate weights less than 1.9 kilos and the disk with center weights 0.6 kg.

And as always, there must be also a question.

Can you suggest any throw out bearing to use? Should be a one with radius contact patch to match pressure plate.

Also would like to found actuator which could been mountend around the clutch axle with some more piston area than the original. I remember that that kind of actuators are used in some Saab's (95?), but don't know about the dimensions.

nice, should save the synchros.

there are a lot of different throw out bearings avalable from tilton and AP...

Heres some pics of my clutch project. A fair amount of machine work was involved.I made the concentric slave as its the only reasonable way to actuate the stiff clutch. Unfortunately I did not realize how much stiffer the pressure plate is over stock and will have to remake the slave with more area. Still results are very encouraging. Unbelievable improvement in response and shifting. Some judder on startoff but I drive this setup to work and in traffic wich is a pretty brutal test of this type of clutch. So far so good. When I replace the slave Ill post more pics of the wear so far.
-Tom Phillips.

Very nice job Tom, also the finishing seems to be perfect

Did you scaled the whole rotating package? Mean shaft+wheel+disk+pressure plate.

How much area you have now on the slave cylinder and how much you think it should be when making the next version?

I am also going to fit a concentric slave. It have area of ca. 660 mm^2. Original slave has ca. 510 mm^2, but with ratio of 1.58 it's equal to 800 mm^2. That means I'm trying to use slave with 22% less force than in original setup.. Guess I need to find smaller master cylinder.

Hi, the current slave area is 630mm2 but I figure Ill need double that for comfortable pedal pressure. Let me know if you find a good master cylinder wich fits. I tossed the entire rotating package except for the shaft. There really wasnt much to be gained by remaking it so I kept it. What did you do for the spline? Did quartermaster have the 19 tooth broach?

Thanks for posting Tom..My question again..Did you fabricate the pressure plate yourself as well??I realy like your stuff..

The pressure plate is from RAM. I did the flywheel assembly. Not much point in making the pressure plate with so many good clutch makers around. I did the flywheel asembly and slave. I also had to mod the disk hub cause the supplier did not have the odd ball broach for the alfa spline. What about your disc? does quartermaster have a hub to fit the alfa transaxle?

BTW: Ram said this single disk can handle 500lbs torque. Let me know if you find an alfa v6 that needs more!

Quartermaster doesn't have centers with suitable spline for Alfa, at least I couldn't find it from their list. I broke two standard disks and took centers from them. Some turning on lathe, bolting them on friction plates and voila.

How much force you need when pressing the clutch pedal? Do you think it's also too much for racing? There is no need to slip the clutch much, but don't want to put all the effort avaliable on pressing the clutch.. If you think so, I'll start looking for a new master cylinder or check if the pedal ratio could been modified.

The pedal effort is high enough to mess up easy heal and toe shifting. Plus, it cant be good for the clutch pedal pivot and master. I dont know what the stock master diameter is but if you calculate the ratio based on my slave area Id size it to give at least double that value.

Helix has the disks with Alfa spline.

Thanks Tom. Your experiences strenghten my assumptions. I might make some changes before first test.

Ok, let me know how it goes!

Thanks Tom..Normally thebigger clutch guys cast pressure plate backings..I saw yours was billet and wondered if you had made it ..excellent.

In the 80`s and early 90`s AP made a 3 puck disc for the std gtv6 twin plate clutch with the correct splined center..There might still be some of those lying around. For interest sake they also supplied a std Alfa presure plate with an uprated diaphram..I bought my lsat new complete AP clutch in 1996...

Tom,Maserati use a "knee effect" helper spring on the Ghibli`s clutch..So do all new 156 road cars..This might be something to look at...This is a mechanical help via the pedal fyi..

The 164 has this help as well. Found it out the hard way trying to fix papas car (broken spring in the clutch master . )

My 75s has that too, springs in the pedal assy that help you keep the pedal depressed.

Hardly a racing driven design.