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Re: Spyder Chassis

PostPosted: Tue Nov 12, 2013 6:21 pm
by Spyder fan
twincamman wrote:"darlin" makes me keep my back to the wall and my soap on a rope


Whatever floats yer boat Ed baby!

Back to Spyder chassis:
Had an interesting discussion with Andy Widnall (Spyder main fabrication man) about noise, vibration and harshness a few years back circa 2006. He has experimented with different material between the chassis and the body rather than the normal felt/hessian fire proofed material and come to the conclusion that original is best. He used a space blanket foil backed glass fibre mat material once, it had a good write up with so called superb sound deadening properties as well as insulation properties, it also had the advantage of being much less hygroscopic than the standard felt/hessian, so he thought he was on a winner. It turned out that the glass fibre matting liked to resonate all of the sound vibrations through the cockpit so that you thought you were driving a type 14 Elite, I think it was realised that the glass material would only compact so much and became in effect a solid layer where the body/chassis beared upon it, so as you will notice from my build up chassis photo's it's back to original!

Re: Spyder Chassis

PostPosted: Tue Nov 12, 2013 6:35 pm
by stevebroad
twincamman wrote:Guys suspension set up is not that hard .its all about the tire footprint on the road ,common geometry applied with a protractor and a string in a straight line .Its all very simple tire caster and camber ..toe in..bump..and tire pressure ....if a bounder like me can understand it than you can and save big money doing things your self .I don't (or didnt )trust any one to set up a car I intended to drive in anger , the hired guns don't have to fix the car or me when a setting is wrong and "sorry" won't fix any thing Unless your one of the gentlemen whose knee never touches the ground get involved! I would rather have to listen to a Celine Deon album than pay some one to set up my car ...Ed


I understand the theory, sort of, but not well enough to be able to set the car up properly. I will be leaving this to Graham Hatherway who does know what he is doing. He's been there, done that and got all the T-shirts available.

Re: Spyder Chassis

PostPosted: Tue Nov 12, 2013 7:42 pm
by GrUmPyBoDgEr
twincamman wrote:Guys suspension set up is not that hard .its all about the tire footprint on the road ,common geometry applied with a protractor and a string in a straight line .Its all very simple tire caster and camber ..toe in..bump..and tire pressure ....if a bounder like me can understand it than you can and save big money doing things your self .I don't (or didnt )trust any one to set up a car I intended to drive in anger , the hired guns don't have to fix the car or me when a setting is wrong and "sorry" won't fix any thing Unless your one of the gentlemen whose knee never touches the ground get involved! I would rather have to listen to a Celine Deon album than pay some one to set up my car ...Ed



Oh deary me you do make it all so simple to understand; if only that was the case.
Camber influences through wishbone lengths & pivot points is but one aspect but more complex & to the eye invisible geometry such as roll centres make the whole business much more complicated.
Setting your tracking & camber angles with bits of string is the bit you might be able to do but the rest is already designed into your car------------------------& that is the very clever stuff.
Take a read of Len Terry for deeper insight.

Re: Spyder Chassis

PostPosted: Tue Nov 12, 2013 8:44 pm
by stevebroad
Taken your advice and just bought "Racing Car Design and Development" by Len Terry from Amazon :-)

Re: Spyder Chassis

PostPosted: Tue Nov 12, 2013 8:54 pm
by Maulden7
Back to Spyder chassis:
- yes please & I apologise if my post threw things off a bit (I was simply trying to demonstrate that the original Lotus design - when set up carefully - can do the business - I don't claim to have any driving skills - I simply point the Elan & pray & it seems to go round pretty well ..... most times - also in the pic there is a 16 stone passenger which doesn't exactly help when turning right)

I've not driven a Spyder chassis Elan, all I do know is that many years ago (when Vic Thomas was there & I lived nearby in Peterborough) I spent quite a few hours picking his brains re Elan suspension, & he enthusiastically helped me a lot.

I have no doubt that they do know what they are doing, & obviously a well designed double wishbone set up should, in theory, work better than the Lotus strut / lower wishbone design.

I will be at the NEC as well on The Sunbeam Lotus OC stand (hall 11 - stand 225) setting up on Thursday & manning on Sunday, so will try to pop in to the Club Lotus stand for a chat (I have been a CL member since 1987 I think)

Dave M.

Re: Spyder Chassis

PostPosted: Tue Nov 12, 2013 9:36 pm
by twincamman
well Grumppy if youcan build an engine you can set up a suspension especially as you say thereis much built in .You dont learn if you dont try amd there are books and books on the subject ....perpare to win is one of the best ....but not on vee suspension though

Re: Spyder Chassis

PostPosted: Tue Nov 12, 2013 10:14 pm
by stevebroad
twincamman wrote:well Grumppy if youcan build an engine you can set up a suspension especially as you say thereis much built in .You dont learn if you dont try amd there are books and books on the subject ....perpare to win is one of the best ....but not on vee suspension though



All Carol Smith's books are good, if a little over opinionated :-)

Re: Spyder Chassis

PostPosted: Tue Nov 12, 2013 11:34 pm
by GrUmPyBoDgEr
stevebroad wrote:Taken your advice and just bought "Racing Car Design and Development" by Len Terry from Amazon :-)


Ah yes!
I should dust off my copy & give it another read but I'm so far behind with my reading nowadays.
Colin Chapman "Inside the Innovator" is still only part read & how long has that been out now? :oops:

Re: Spyder Chassis

PostPosted: Wed Nov 13, 2013 9:29 am
by vernon.taylor
Salut

I had the chance to compare my Lotus galvanised chassised +2 CN cabriolet with a mate's freshly restored Spyder chassised +2 CN cabriolet. I would of thought that this would amplify any differences due to the longer/wider chassis compared to the Elan, and the lack of stiffening roof.

My car was expertly restored 5/6 years ago with fresh shocks (adjustable front) and standard Lotus suspension components and rotoflexes. Roland's car has new Spyder suspension all round including their rear suspension mod and CV driveshafts. Both cars have been checked for suspension height and geometry.

So my purely subjective findings: Roland's car felt stiffer resulting in less to almost non-existant scuttle shake over bumps. The suspension felt like a modern car - harder but at the same time more damped/comfortable over road imperfections. However, and I was surprised, the rear end felt less controlled compared to mine - I felt some twitching and induced a skip or two on fast tight corners. My car stayed glued to the road at the same speed and from experience I know I have to scare myself and/or drive over gravel to get the rear to slide.

I didn't feel as much difference between rotoflexes and CV drive shafts as in the past - don't understand that as i don't think my awful driving has improved.

So FWIW it would seem that a Spyder chassis with stock Lotus suspension would suit my car and my driving best. As already said, though, there are too many variables to be sure and my prejudices and interpretations are probably not neutral.

@+

Vernon

Re: Spyder Chassis

PostPosted: Wed Nov 13, 2013 5:02 pm
by ecamiel
I was involved in setting up an SCCA ?lan in the 60's before space frame cages were legal.
We found the chassis was a noodle except in torsion. In the horizontal plane it moved easily.
Don't believe me? Ask anyone who has ever driven a Lotus 30.
Also found that a prepared 26 was faster in some conditions that a similar 26R. What we realized was that
most of the chassis reinforcement in the 26R was there just to keep it from cracking. Any little added stiffness was a bonus.
The standard 26 was better because the stiffer heavy stock body was adding significant stiffness which the light weight 26R body didn't offer.
What we did was reinforce the light weight body, particularly in the suspension load areas and in the horizontal plane and thru bolt the body to the chassis. It worked wonders.
Chapman got much right with the suspension/chassis combo and fixed more with the 26R. However, at street spring rate and ride height the rear can "jack UP" and produce sudden trailing throttle and breaking oversteer. Also, engaging the bump stops will produce oversteer.
The front is better IF at ride height. Front and back, the lower wishbones should be parallel to the ground. The 26R uses a drop link lower front to achieve this while leaving sufficient travel.

Rohan, care to comment?

Eric
64 S1 Hart - (ex SCCA race car)

Re: Spyder Chassis

PostPosted: Wed Nov 20, 2013 11:07 am
by alan
with the Spyder chassis there is also the question of homologation or type approval (vosa utac), depending where you live :|
It's the same problem for the cabriolet +2.
IMHO i think it's best to stay with the original design

Re: Spyder Chassis

PostPosted: Wed Nov 20, 2013 11:51 am
by jimj
It`s only happened once but a few years ago we entered our 1967 car in the Rallye des Alpes. It is, or was, for pre-1963 cars but I argued that Elans had entered production then and was granted entry but was specifically asked if the car had a "proper" Lotus chassis. We also needed the FIVA paperwork, and have since, which required the car to be certified by, as a minimum, a club official. I don`t remember the club official; my mate Gareth, honorary CLOG inspectorator, being overly officious.
Jim

Re: Spyder Chassis

PostPosted: Wed Nov 20, 2013 5:29 pm
by vernon.taylor
Salut Alan

Do you have a +2 cabriolet ? Did you have trouble registering it in France ? Spyder or Lotus chassis ?

@+

Vernon

Re: Spyder Chassis

PostPosted: Thu Nov 21, 2013 12:54 am
by gus
homologation, really?

what percent of these cars are raced, ever?


All original chassis are on their way to failure.

I personally feel the Spyder is superior, and no one has found a reason, financial or performance to prove otherwise. A car with a new chassis is always preferable to an original, outside of a museum.

Actually I lied, if you want a 5 speed, get a lotus replacement, the spyder is tighter

Re: Spyder Chassis

PostPosted: Thu Nov 21, 2013 8:28 am
by Spyder fan
gus wrote:homologation, really?

what percent of these cars are raced, ever?


All original chassis are on their way to failure.

I personally feel the Spyder is superior, and no one has found a reason, financial or performance to prove otherwise. A car with a new chassis is always preferable to an original, outside of a museum.

Actually I lied, if you want a 5 speed, get a lotus replacement, the spyder is tighter


Gus,
it is sometimes difficult to register an imported car in parts of Europe especially if the car differs from it's factory new state. If the car was supplied new to the country where you want to replace the chassis/frame, then that makes it a bit easier but you still have to be careful.

No doubt Vernon has some experience and can advise further.