Best pressure plate for 356A

[Dean Davies]

After emailing several vendors I have received contradictory info as to what pressure plate is best for my car I have a 58 356A with a couple of mods that achieves 70HP at the wheels prior to receiving recent freshen up.
The standard 6 spring 180mm clutch and PP in good order, clean and within spec has started slipping in all gears when driving spirited.
According to the Original Porsche parts list the 6spring PP was standard up to 55kW flywheel at which time higher power outputs required the 9 spring.unit.
In any case is the diaphragm PP version that replaces the 6 spring capsble of dealing with 70hp at the wheels or are their other options?

[David Jones]

The diaphragm type PP is definitely the way to go. I also prefer the lighter rigid clutch disc as opposed to the one with damper springs.

[Al Zim]

Three types of clutch disc's are available. The solid 180 MM (used mostly in the very early VW's) the disc with smaller springs also used in the VW and the disc still 180 with larger springs. The purpose of the springs is to reduce the shock loading on the synchronizers on rapid acceleration. WHY??? Because Porsche developed this WONDERFUL SYNCRONIZER!!! When 100's of Million cars use the brass ring synchronizer from Borg Warner. VW used the bass ring on all their synchronized transmissions and Porsche finally did with the G50 (1987) transmission.
PRESSURE PLATES: 6 Coil springs 180 MM were the VW sedan pressure plates and to the best of my memory they were present in the 36 HP kombi and Pick up truck. The size still remained 180MM but were 9 spring units. For the T-5 1960 the pressure plate was a 1 piece Hauserman style Which required a throw out bearing similar to the 911/2 and 914 and a guided shaft for the throw out bearing. (too much involved to install on a 644 transmission.)
If this is a normal situation and you can find the 6 spring pressure plate and VW transporter roller bearing throw out bearing, the clutch disc with large springs this is the best choice. It should work forever.
If the clutch release arm on the transmission has a hole the clutch cable goes through call me and I will tell you how to make clutch adjustment easy. Zim

[Martin Benade]

As for the spring center or solid disc, from driving the car you’d never know the difference. Either one is fine.

[Jay Darlington]

i installed a Kennady pressure plate its a diaphragm style. it doesn't slip ( i have100hp) BUT it is hard to push in, hard enough thats its almost uncomfortable. i have a new 9 spring Sachs pressure plate and have thought about trying it. i don't really know if it would be LESS stiff or not that noticeable or posibly slip ( never have used one). we use to run VW baja bugs w/ sand tires in the sand here with the bus 9 spring. around 50-70 hp they were fairly reliable IF you were sensible (didn't try to climb a hill in 3rd gear). most of us did change to a 200mm they were much better. personally, i would think the 9 spring would be good for the street.
Jay D.

[Dean Davies]

i installed a Kennady pressure plate its a diaphragm style. it doesn't slip ( i have100hp) BUT it is hard to push in, hard enough thats its almost uncomfortable. i have a new 9 spring Sachs pressure plate and have thought about trying it. i don't really know if it would be LESS stiff or not that noticeable or posibly slip ( never have used one). we use to run VW baja bugs w/ sand tires in the sand here with the bus 9 spring. around 50-70 hp they were fairly reliable IF you were sensible (didn't try to climb a hill in 3rd gear). most of us did change to a 200mm they were much better. personally, i would think the 9 spring would be good for the street.
Jay D.

Thanks Jay, I made an enquiry to KEP and they told me they didn't do anything to suit the A with the center ring. Your experience is certainly interesting, maybe I will travel down that path.

[Dean Davies]

As for the spring center or solid disc, from driving the car you’d never know the difference. Either one is fine.

Hi Martin, that's very interesting. I'm sort of inclined to believe Porsche engineers know better than me and that's why I reluctant to mix PP and throw-out bearing combinations. Are you saying that they perform in all respects equally well as far as paring an A Throw-out bearing with a Diaphragm style PP?

[Dean Davies]

Three types of clutch disc's are available. The solid 180 MM (used mostly in the very early VW's) the disc with smaller springs also used in the VW and the disc still 180 with larger springs. The purpose of the springs is to reduce the shock loading on the synchronizers on rapid acceleration. WHY??? Because Porsche developed this WONDERFUL SYNCRONIZER!!! When 100's of Million cars use the brass ring synchronizer from Borg Warner. VW used the bass ring on all their synchronized transmissions and Porsche finally did with the G50 (1987) transmission.
PRESSURE PLATES: 6 Coil springs 180 MM were the VW sedan pressure plates and to the best of my memory they were present in the 36 HP kombi and Pick up truck. The size still remained 180MM but were 9 spring units. For the T-5 1960 the pressure plate was a 1 piece Hauserman style Which required a throw out bearing similar to the 911/2 and 914 and a guided shaft for the throw out bearing. (too much involved to install on a 644 transmission.)
If this is a normal situation and you can find the 6 spring pressure plate and VW transporter roller bearing throw out bearing, the clutch disc with large springs this is the best choice. It should work forever.
If the clutch release arm on the transmission has a hole the clutch cable goes through call me and I will tell you how to make clutch adjustment easy. Zim

Thanks Mr Zim, Thank you for your wisdom and your authenticity. Whenever a seller promotes another product, I tend to think they are a little more trustworthy, that is assuming you are allzim.com I always canvass your site when I have a purchase in mind. In fact, im curious as to why you would not recommend the diaphragm replacement product for the "A" PP on your website.
Yes, the clutch release arm does have a hole which the cable runs through with two nuts on the other side. Are you suggesting I do the adj under the pedal board instead?

[Dean Davies]

The diaphragm type PP is definitely the way to go. I also prefer the lighter rigid clutch disc as opposed to the one with damper springs.

Thanks David, how is the diaphragm wearing with the standard "A" throw-out bearing? Or are you talking about the diaphragm replacement product with the center ring?

[David Jones]

Yes, the one with the collar which is removable if one wished to use it with just the fingers.

[Dean Davies]

Yes, the one with the collar which is removable if one wished to use it with just the fingers.

Thanks David, is your engine standard or modified? If modified, would you mind telling me a little more about it.

[David Jones]

Both my A cars have the diaphragm type pressure plate. My A coupe with 1720 cc big bore and Solex carbs has around 90 hp and the180 mm clutch.

[Martin Benade]

Dean, I referred only to the disc hub which is available with or without springs. Either of those will mate with any pressure plate that doesn’t interfere with the hub.
Regardless of the disc the throw out bearing and pressure plate still must be paired in factory recommended combinations.

[Alan Hall]

Since VW used 180mm pressure plate with collar for years, you might try VW part places. Current 180mm diaphragm clutches, with collar, are, I think, fairly readily available. For instance CIP-1 shows one for around $69. their p/n VWC-211-141-025-D. Also the SACHS 180mm diaphragm pressure plate w/collar that was made in Brazil used to be readily available but I don't know current availability.

[Martin Benade]

Cup-1 is a good outfit to deal with.