Lightweight CV Joints

Part of me thinks, “Whoa, what a great place to save weight,” and the other part of me thinks, “That one of the most robust-structural-demand parts of the vehicle; not sure how I feel about less heft.”

Also, for 4x108 GBP, that better be meaningful weight savings.

 

Did some quick research, and this MIGHT be their supplier/mfr…

https://www.primusracingparts.com/gkn-Lightened-Honed-HD-Lobro-CV-Joint-6-x-78mm-BC-33-Spline-_p_16.html

Our OEM joints and shafts are by Lobro, and this lightweight product claims to reduce 12oz per unit, or 1.5lbs per corner. You’d have to want to push a 308 pretty hard to spend $500 to lose 3lbs.

PMB performance used to offer OEM-spec lightweight calipers that saved 5 or 10lbs per corner for that price, IIRC.

How hard were you planning to track your car?

 

I rebuilt my axles in January 2021 - they didn't really need full rebuilding, as just one of the boots was split, but if you have to replace one split 36 year old boot you might as well replace all 4... then you need to re-grease the 4 CV joints... then when you're that far in with the labour, replacing all the CV joints seems like a good idea

I used the standard Superformance CV joints,they didn't offer a lightweight version at the time - they're the OEM GKN CV joints. Porsche used the exact same CV joint on 930 and 911 models of the same vintage, so you can also source them from many of the US-based shops like Pelican, Autohauz, etc etc. Pretty much everything was new except for the axles and the curved double-bolt washers:
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On reading your post, I was skeptical that any weight savings would be significant, as the rotating diameter is not really large enough for the inertia difference to be significant, and the unsprung weight different would be pretty small as well. On a racing car, sure, but on a classic sports car, doubtful? And as Justin noted, is that a great place to potentially reduce load capacity?

But, a quick search shows that lightweight CV joints are offered in the Porsche world for 930s, and one such unit by Kartek looks pretty much identical to the Superformance unit - Kartek Off-Road Lightened And Polished Porsche 930 CV Joint, for $220 USD.

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I guess the big question is who makes/modifies the similar Superformance unit?!

Regards,
Gordon

 

I think they only offered the lightweight rear calipers - at any rate, I bought a set of lightweight rear calipers from them in ~2014 when they had them on sale for 50% off. It was cheaper than sending the stock heavier rear calipers to them for rebuilding!

Gordon

 

Obviously not . The question is are they strong enough for a road car meant to go 100K-200K miles worth of cycles and abuse? Would love to see an FEM stress analysis of both. Losing having each bolt complete captured in a solid hole over its whole length makes just tightening the bolts a different clamping situation.

 

Yeah, that wonderful Unobtanium stuff . My initial thought was: "Well, they did it in a way that is the least difficult to machine, but with these multi-axis CNC machines you could come in from the outside with an radiused end mill (or a ball end mill) and remove about the same material, but leave solid columns of material around the holes". Would think that you could also put some shallow blind holes in the faces, too -- wish I had a reason to do interesting stuff like that...

 

How about just drive with no more than a 1/4 tank of gas?

Less weight and factory strong cv joints!

 

3#? Drive naked?

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Just stumbled across this looking for some replacement CV joints. I bought the lightweight joints from Superformance. They are junk.

Nothing is machined to the right dimension and there are large sections of the inner star grooves that didn't even get touched during machining so they bind.

 

Thanks for the info

 

Agree, thanks.

People want to really believe reinventing the wheel will yield improved results.