After about six months probing and researching I have at last been able to put together a definitive list of SACHS 020 OE and SRE Cover Assembly torque capacities. OE 200mm Cover Assy: 88 3082 108 035 = 175Nm SACHS SRE Performance 200mm Cover Assy: 88 3082 999 560 = 220Nm OE 210mm Cover Assy: 88 3082 149 541 = 250Nm (5.0mm Thick Cover) OE 210mm Cover Assy: 88 3082 149 436 = 250Nm (5.0mm Thick Cover) Sporting 210mm Cover Assy: 88 3082 149 652 = 250Nm (5.5mm Thick Cover) * SACHS SRE Performance 210mm Cover Assy: 88 3082 999 616 = 295Nm (5.5mm Thick Cover) - CI Pressure Plate SACHS SRE Performance 210mm Cover Assy: 88 3082 999 606 = 295Nm (5.5mm Thick Cover) - Aluminum Alloy/Hard Faced Pressure Plate = VWMS * This Pt. Num.: 88 3082 149 652 came thanks to Willber from his 16v Sporting Kit: 88 3000 963 001 The 8v Sporting Kit: 88 3000 960 701 is now NLA. But. SACHS have sent me a part number for a Sporting Kit which may suit the 8v. I need to reasearch the kit before publishing.
Willber's image. Ta so, Will. The pressed bosses which provide the tappings for the 9 x M7 bolts are 1mm taller due to the extra 0.5mm thickness in Sporting and SRE Cover Assenblies. IE. 12.5% longer thread.
I've got a Helix clutch that uses a similar clutch cover - same stamp on it. I wonder if they rebuild it, or if it's just the stock item. Standard Sachs clutches have that same stamp I think, or one that's very similar.
Mike. TypM210X is Sach's identification for the 210mm 020 Type clutches. The thicker 5.5mm cover pressing is stamped 5.5 to identify it: This may answer your Helix question? Hi Dave, all the single parts ( diaphragm spring as well as the housing ) are cancelled! Furthermore, we are not allowed to send you single parts for an refurbishment, done by yourself - sorry! One thing you can try: An official distributor of ZF Sachs Race is allowed to refurbish some OE-Sachs clutches. Maybe he is able to supply you with an stronger application of 3082 108 035 which is the OE 200mm clutch! The contact: Fa. Hennig Bottroper Strasse 30 45141 Essen Tel.: +49 (0) 201 63 03 151 Mail: manfred.samel@hennig-fahrzeugteile.de http://www.henniggmbh.de Mit freundlichen Gren / Kind regards Markus Hammer Techniker / Technician ZF Sachs Race Engineering GmbH >Ernst-Sachs-Str. 62 >97424 Schweinfurt / Germany >Tel: +49-(0)9721/98-5877 >Fax: +49-(0)9721/98-92561366
200mm Thoughts The reason I was interested in the 200mm 020 clutches was that the flywheel has more meat around the periphery. With the extra material, 9 x fitted bolts could be used. This would remove any possibility of the two parts, cover and flywheel, from sliding. The max. torque capacity of the SRE 200mm clutch was quite dissapointing at 220Nm when compared with 250Nm of the standard 210mm unit. On area ratios, 1.1025:1, I expected the 200mm unit to give: 295/1.1025 = 267Nm. Which would have been grand so. So, I went off that idea.
I'll have a look at the Helix bits and see how it's stamped up, and take some pics for your perusal With a standard cover 'capable' of 250nm, why does anyone with an NA engine need an uprated clutch?
Mike. I am advocating looking at a Sporting Clutch, which is still only 250 Nm, for NA cars for the following reasons: You get a realease plate without punched nibs. (Image courtesy of Willber) SO this does not happen. The extra 0.5 mm of thickness has a number of effects: There is 1mm extra metal in the thread where the 9 bolts screw in. This gives an extra 12.5% more grip length. There is an extra 10% of metal at the face where it fits on the crank. So, the bolts have an extra 10% of stretch to breath. Thus 10% less chance of losening. The extra thickness at the crank face means it will distort less due to the overhanging weight of the pressure plate. The extra 10% thickness means that the cover assembly will deflect 33% less vertically at the pressure plate face due to deflection being proportional to the thickness cubed. The lowest critical speed, the speed at which the clutch whirls, is proportional to the square root of the thickness cubed dividee by the overhanging weight. The extra 0.5mm adds approx 5% to the total weight of the cover assembly, so the lowest critical speed rises by 2.56 x 0.565 = 145%. So if a standard clutch is good for 6500rpm then the Sporting will good for 9450rpm. The down side is that the Sporting Clutch will have 5% more inertia to accelerate away! I need to ask Markus what the weights of the cover assemblies are, for all we know the Sporting Cover Assembly may be fitted with a lighter pressure plate?
Dave... what about the torque capability of the Diesel clutches ? I thought that was a cheap upgrade back in the day.
Tris....I believe that the Diesel clutch upgrade may have been true for small capacity upgrades. eg 1400, 1500 and 1600cc big block motors. The 200mm and 210mm Diesels use the same cover assembly as the Gtis.
The std. clutch(210mm) is proven to be good for 8400rpm. Tried and proven by myself. But the contributing factor that may well help this is there's was a fair bit of material missing from the flywheel, which hasn't been taken into consideration with regard to ovarhang distortion as a whole unit. Could you work the figures out for a flywheel weighing 3kg and not 5.5? As for the M9 bolt upgrade with the extra 1mm taller bosses, once you've removed the extra 2mm from the i/d of the boss there's not alot of material left of the pertruding area at the rear , would it be possible to use a countersunk lock nut on the bolt also? Or use a few more 'solid' dowels ? Daved, do you have some compaison pics of the 200mm flywheel against a 210mm one to see the extra material you're looking at? I haven't got any here to compare side by side. What sort of application are you using it for too, as there's not may n/a engine on here I know of producing upto or more than 184ft/lbs? Or are you wanting to use an 020 box with a turbo/charged engine? As for the clutch centre plate, it maybe worth looking into having some made from something a little more heavy duty rtaher than some pressed steel. Some En24t heat treated after machining with something 'special' as a centre piece. This way you could have have it made to 'fit' and notfloat about so much. Just a thought as it wouldn't take alot of work.
What shall I do first. me thinks! You have asked a lot of quetions which are pretty deep, and I need to find some data to answer them fully. But. I will make the effort, as positive interest from someone like yourself, who contributes pro-actively to CGTI, deserves a meaningful response. The easy one is the release (centre) plate. Making one from EN 24 or other through hardening alloy steels is not infeasible. But. One thing you will notice from the image of the Sachs Sporting release plate is the induction hardening around the periphery. This thing will have been made from an uber high carbon spring steel. Enough carbon so that it will induction harden easily. The hardness will be slightly higher than that of the diaphragm spring fingers, on which it operates. This to stop massive wear during operation. To do this with EN 24 you would need to introduce extra carbon just into the edges where it sits on the diaphragm fingers. There are ways to do this. I used to stick alloy steel parts into a closed thick steel box full of charcoal, and leave it in the small lab. furnace, at about 1200 C, for a couple of days. Let it cool slowly in the furnace for a day. Take it out and flame harden the surface. So. It would be easier to fit hardened wear plates right around the periphery. You could make them from old diaphragm springs. Being careful not to over heat them when grinding. They can be carefully welded on, using Cr-Ni wire. ie Pre-heat, slow cool. The centre pip on my broken release plate is welded in thus. EDIT: 05.50 hrs, and I've just had a think! I could design one out of Aluminum Alloy, with spring steel inserts, if you like? Titanium Alloy would be best though. I wonder if I could get a cover plate made from Ti as well? Brian.G was flabbergasted, when I showed him my Ti Zippo, as the casing is so deep drawn!
Morning Dave How about some Hardox plate or a welded hardox layer machined back where needed? Or am I barking up the wrong tree? I know we have some grades of these rods that unbelievably hard, although I've not had chance to put my hardness tester on a sample as the finish we require isn't good enough for the needle to get an accurate reading. Can you still get carbonite these days for heat-treating? Or was the stuff banned years ago lol
Hi Mart. I have never heard of Carbonite? Used to use Kasanit, of which I had forgotten, something similar here: http://www.knighton-tools.co.uk/cgi...se+hardening&PR=-1&TB=A&search.x=0&search.y=0 Hard facing is a possible. Used to hard face railway wheels back in the day. Not too sure how hard you can get the surface though. The rods we used gave a soft enough surface to turn using a carbide tip. I recon that you'd have to hard face the edges of the slots where thay touch the sides of the three raised fingers. I might worry about cracks in the surface. I supose with careful pre and post heating these could be avoided? I was going to look into Spray Hard Facing for Ally bits. Not got any further on that yet though. When I worked at PERA, I used to stay in a B&B where one of the other residents was PERA's Hard Facing expert. I have forgotten his name after 30 years though. He will have retired now, as he was even older than I! Wish I had been interested in Hard Facing in those days. All we talked about was cars. Or, should I say? All we talked about was how 5hi77y his Beemer was compared to my ****.
Mart. Just had another revelation. Take a standard release plate. Machine the centre out leaving just a ring, with enough metal around the cut outs so it does not fall into three separate peices, which will sit snugly under the alloy steel plate. The lip on the edge of the original release plate will stop it floating around. Just need to work out how to add a thin layer of hard surface to the edges of the slots in the alloy steel plate, where you want a snug fit, to stop it wearing on the edges of the raised fingers. Perhaps Kasnit will be usable here? For my Aluminum Release plate I'd have to fit hardened spring steel inserts into the slots!
Hmm, i know a mate who works for a company that does the hardened spray coating for the Mod. This stuff is super tough! I'll see if I can get a bit more of an insight into it. Kasanit, thats the stuff. Think the original mixture was banned for being carcinogenic lol
Ta Jon. Mart. Check out this thread. In it I try to explain my thinking on getting a more reliable 210mm set up using dowels, etc. http://www.clubgti.com/forum/showthread.php?t=215756&highlight=ARP Also. I was looking at the 200mm clutches because the cover assembly attachment bolts go through fully cylindical holes in the flywheel, compared with the cut-aways in the 210mm flywheel. I wondered if there was enough meat in the periphery to machine the bore to take a 210mm driven plate and still leave a hole which was, more-or-less, a full cylinder. (Note to self: Try to get hold of a 200mm or, perhaps better, a 190mm flywheel!) These could then be reamered out, very slightly, so that fitted bolts could be used. Doweling would then be obviated, and assembly/dis-assembly simplified. I don't like the idea of using larger threads with any kind of nut. IMHO, M7 fine thread are good enough if one can stop the things wanting to slide.
The ultimate in 020 clutches: 5.5mm Cover pressing. Aluminum Pressure Plate. Triple leaf link plates. The tolerances on the cover pressing must be much tighter than on a standard clutch? I had to force the cover into the flywheel as the fit, between the two dowels and the slots, was uber tight. I had to lever the edge of the cover up to the dowels to align all 9 bolt holes. It took a lot of getting out again. I ended up jacking it out.
