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CV vs Donuts Poll

PostPosted: Sat Sep 18, 2010 7:55 am
by terryp
Perhaps it was time ........

Re: CV vs Donuts Poll

PostPosted: Sat Sep 18, 2010 10:26 am
by Robbie693
Hi Terry,

I was tempted to select cream buns as you didn't put TTR's uj shafts as an option..

Or by cv's do you mean all solid driveshafts?

Cheers, happily munching,

Robbie

Re: CV vs Donuts Poll

PostPosted: Sat Sep 18, 2010 10:33 am
by terryp
Robbie
Updated , I think that's everyone?
It could be an interesting outcome
Not many votes for Donuts yet? Perhaps Cream Buns will be more than Donuts .......

Terry

Re: CV vs Donuts Poll

PostPosted: Sat Sep 18, 2010 1:26 pm
by Old English White
... You have my vote.
TTR's uj shafts on "OEW"...
Christian.

Re: CV vs Donuts Poll

PostPosted: Sat Sep 18, 2010 11:52 pm
by Gordon Sauer
Chapman chassis, Chapman donuts. Gordon Sauer

Re: CV vs Donuts Poll

PostPosted: Sun Sep 19, 2010 2:02 am
by CBUEB1771
Gordon Sauer wrote:Chapman chassis, Chapman donuts. Gordon Sauer

What makes you think they are Chapman donuts? He didn't design them, they were catalog items. If he (rather than Ron Hickman or anyone else actually doing the design) chose them it was to deal with the rear axle length change in the cheapest way possible, i.e. no sliding splines in the drive shafts. If CV joints with plunge motion were as ubiquitous in 1960 as they are now I have little doubt that Chapman (or Hickman) would have gone that way. Donuts introduce a small but oscillating variation in the wheel spring rate as the vehicle moves, increasing with greater deflection from slight bump. I have to think that Chunky really didn't like that.

Re: CV vs Donuts Poll

PostPosted: Sun Sep 19, 2010 5:04 am
by Gordon Sauer
I'm just throwing down the usual "as it was" notion--you start changing any or all around then it's not his (Chapman). When I tell people the front end is only adjustable for toe-in they think that was cheap and don't buy the "if I let em adjust it they'll screw it up" but I wouldn't want al the adjustable arms now available--I can see all the track folks doing it but at some point it really stops being a Chapman Lotus--maybe a Spyder one and not what it was--just preference. Gordon Sauer

Re: CV vs Donuts Poll

PostPosted: Sun Sep 19, 2010 5:04 am
by Gordon Sauer
I'm just throwing down the usual "as it was" notion--you start changing any or all around then it's not his (Chapman). When I tell people the front end is only adjustable for toe-in they think that was cheap and don't buy the "if I let em adjust it they'll screw it up" but I wouldn't want al the adjustable arms now available--I can see all the track folks doing it but at some point it really stops being a Chapman Lotus--maybe a Spyder one and not what it was--just preference. Gordon Sauer

Re: CV vs Donuts Poll

PostPosted: Sun Sep 19, 2010 12:44 pm
by terryp
This must the most interesting poll ever. I thought it would be 50/50 but at the moment 77% are using or intend to use solid driveshafts in lieu of the "original" set up
More than that - 6% are actually baking and using cream buns!!!!!!!! thus saving money on do-nuts or solid driveshafts, whether they get very far is another question!
Terry

Re: CV vs Donuts Poll

PostPosted: Sun Sep 19, 2010 4:03 pm
by summerinmaine
Gordon Sauer wrote:I'm just throwing down the usual "as it was" notion--you start changing any or all around then it's not his (Chapman). When I tell people the front end is only adjustable for toe-in they think that was cheap and don't buy the "if I let em adjust it they'll screw it up" but I wouldn't want al the adjustable arms now available--I can see all the track folks doing it but at some point it really stops being a Chapman Lotus--maybe a Spyder one and not what it was--just preference. Gordon Sauer



I understand the philosophy you describe Gordon, but I just don't subscribe to it. The Elan was a masterful concept from brilliant designers. But like anything else, in transforming the concept into reality, decisions had to be made, compromises accepted, and everything had to be built to a price. That's just cold, hard reality. And Chapman wasn't a deity (gasp!!!!), just a better-than-average human. "He's a witch! Burn him!!!!!"

So when I find a piece that can be improved by resort to modern technology, or when I can afford to toss price considerations out the window (HA!), I never hesitate to make the move. Do you seriously think that CABC would have fitted those gawdawful Lucas starters if modern pre-engaged starters like the Nippondenso had been available for a similar price? I don't, or I'd begin to doubt his sanity. Does my having swapped for a better starter make my car less of an Elan, or more?

Obviously, we would meet in the middle somewhere. I don't think that CN's Evante was an Elan, nor did it pretend to be.

Re: CV vs Donuts Poll

PostPosted: Sun Sep 19, 2010 4:18 pm
by Old English White
Gordon Sauer wrote:Chapman chassis, Chapman donuts. Gordon Sauer

I really wish to , but had bad , short experience with new donuts badly vulcanised or that stay too long on shelf . With the new cams and their extra power/torque , it was time to forget about originality , specially thinking at my position in the car ... But the Chapman chassis still stand .
Christian.

Re: CV vs Donuts Poll

PostPosted: Sun Sep 19, 2010 4:20 pm
by andyelan
Hi Everyone

Just in case anyones interested in a bit of a history.

Given where Chapman was in the late '50 and early '60 it's hardly susprising that he would choose rubber donuts for the Elan as they were in common use on many British racing cars of that era when designers were doing everything they could to avoid the use of sliding joints to accomodated driveshaft plunge. When plunge wasn't a issue, as for example in the Elite and Europa (and for that matter the E Type Jaguar) then solid UJ joints were fine, but sliding joints were to be avoided if at all possible. Far from being cheap and nasty, donuts were actually a very reliable and elegant solution when engine hp was relativly low. Amongst the many cars which used rubber donuts, early GT40s had enormous ones in the drive line untill equally enormous CV joins replaced them on the later Mk2s. The Lambourghini Miura on the other hand had UJs sliding splines in the drive line and suffered terrible handling problems when they would locked up under hard acceleration, this was only cured on late S models when CV joints were adopted. As hp increased to the point where donuts were no longer able to cope with the torque, then CV joins started to take over around '69 '70. The JPS Lotus 72 and subsequent GP cars all used CV joints. There were many exceptions of course and the Lotus 49 for example used UJs and sliding joints and was an extreamly sucessfull car.

As far as which to fit on an Elan today, donuts or CVs, well it's each to his own, all I know is I've fitted a CV joint conversion, had no problems with it whatsoever and it's made a remarkable improvement to the way the car drives. I won't be going back to donuts and as I've said before, I'm "Mr Originality is Everything".

Andy

Re: CV vs Donuts Poll

PostPosted: Mon Sep 20, 2010 8:35 am
by hatman
terryp wrote: - 6% are actually baking and using cream buns!!!!!!!! thus saving money on do-nuts or solid driveshafts


But aren't they worried that, as consumable items, they're not covered by the warranty? 8)

Re: CV vs Donuts Poll

PostPosted: Mon Sep 20, 2010 9:20 am
by terryp
But what side would the cream go?

I'm still surprised at the amount of Non do-nut cars ........

Re: CV vs Donuts Poll

PostPosted: Mon Sep 20, 2010 10:05 am
by peterako
As I'm using Mick Miller CV's at the moment thought I'd give the Cream Buns a try in the future....though I'm pretty sure I'll be back to CV's pretty quickly :D