On the double-jointed Beetle rear suspension (as used on Porsche 924) what is the practical maximum it can be raised?
I would like to gain about 3.5 maybe 4 inches. At this height is there a need to do away with the small oval lower limit stop - and/or modify the spring plate itself?
I'm aware of the spline sizes to enable a precise setting.
Whilst searching the net I found a frightening article on lowering Beetle rear suspension. The owner (for which read non-engineer) had hacked away nearly half the depth of the spring plate. It might have enough residual strength .... but he had notched it with a sharp-angled corner! The perfect stress-raiser to initiate a fatigue failure. Lord help us.
Oh, and he was using ordinary grease on the rubber bushes ...........
Nigel - Can't remember how much I raised mine but it was probably three inches. If you do away with the stop you will need to substitute some sort of stop to limit suspension travel if only so you can jack the wheels off the ground! On my car I ground away as much as possible of the stop whilst maintaining enough strength for it to do its job. Then I nonched the spring plate a bit (no sharp edges). With a bit of geometry you can work out how much you need to remove. The other issues are shock absorbers and drive shaft angulation. I have not changed either and so far no problem 20 years later Michael
ReplyDeleteI reckon the easiest solution for you would be viagra. It certainly works for Michael.........and most other Beetle drivers! Nigel Jones.............Skoda...............sigh.........
ReplyDeleteBeen working on an answer Nigel but I don't think I can come up with one !!!!!!!
ReplyDeleteAm taking tablets for various things such as hayfever but not had to resort to Viagra ... yet. Spent the last hour or two on the Myford machining the cast alloy spacers for the front suspension. Very helpful small foundry in Stroud cast them to my pattern. I offered to take in some scrap alloy castings as source material (to lower the quote a bit) but was politely told they couldn't use it "because it might contaminate the melting pot when we do the Bugatti castings". I was suitably impressed.
ReplyDeleteNigel - I'm curious about your Beetle. Tell us more about it. Presumably its a 1302 or 1303. - Michael
ReplyDeleteThe guide that I tell most people for raising Beetle rear suspension is to set the spring plate so that the lower rear hole for the torsion bar cover is just covered. I left the stop on my car alone, and cut a 10mm notch in the spring plate. Its worked fine for me for over 10 years now. If yours is an early car, you may want to treat yourself to either a set of 944 CV joints or VW Type 2 joints which operate better at high angles that the original 924/VW Type 4 joints. If you haven't sorted out your wheels yet, be aware that although the rear brake drum is identical to the VW Beetle item, the bolt fixing (PCD) is different.
ReplyDeleteMichael. Sorry if I confused you a bit. I'm actually preparing a 924 for trials but asked the question with reference to Beetles that use an essentially similar rear suspension as I thought there would be a broader knowledge base. Simon. Thanks for that info. I had thought that a properly radiused segment might be one way of accommodating the change - glad to hear it does work in practice. The 944 drive shaft gen is interesting. Although I have already got a pair of 924 shafts as spares, I will now have to seek out some 944 ones. As to wheels, will probably start using the 14" alloys with high profile tyres. These wheels are now "cheap as chips" so the odd damaged rim will just add to the Chinese scrap purchases! Currently have 8 to go at. One of the good things about 924's is that they ran on 14", 15" and 16" - so plenty of wheel choice. 15" steels will probably be worth a try - once I have fitted the low ratio diff. - and I gather Citroen Zantia/XZ will fit the Porsche pcd.
ReplyDeleteJust to add a note of caution here. I would not advise anyone running standard vw beetle cv joints to 'notch' their springplate or modify the stop on the torsion bar housing. The type 1 cv joints do not have sufficient angularity to work reliably beyond the manufacturer's design limits - they will fail. Probably when you least want them to.... If you want to raise the rear suspension beyond the normal limits you need to use the larger type 2 cv joints - which were fitted as standard on 924s, camper vans.
ReplyDeleteJust drifting off at a tangent here, but as you have now sold the Allard and purchased a Porsche, are you planning to change your nickname to "Porsche-4-Potter", or maybe "Audi-Special" or even "Stuttgart-Starlet"?
ReplyDeletePS You can check your CV's, assuming they are original, 924 ones have a part number starting 477, 944 ones start 944