LOTUS V SPYDER

[p.faurie]

HI GUYS,
COULD ANYONE COMMENT ON THE PROS AND CONS OF FITTING A SPYDER CHASSIS ON A +2 AGAINST A LOTUS UNIT.THE REASON I ASK IS THAT 3 YEARS AGO I BOUGHT A +2 WHICH NEEDED A NEW FRAME I BOUGHT A SPYDER UNIT ALONG WITH THEIR OWN REAR UPRIGHTS ADJUSTABLE REAR AND FRONT SHOCKS REAR A FRAMES ETC.THE CAR WAS SET UP WITH CORNER WEIGHTS, BUMP ETC AND I THOUGHT IT DROVE REASONABLY WELL.LAST WEEK I PICKED UP A ROUGH EXAMPLE TO RESTORE.I COULD NOT BELIEVE THE DIFFERANCE IN THE FEEL OF THE CAR IT SEEMED TIGHTER THAN MINE,WHEN PARKED SIDE TO SIDE THE RIDE HEIGHT SEEM THE SAME,THEY BOTH HAVE SUN ROOFS,BUT MY ORIGINAL CAR FEELS LIKE A LOOSE FITTING SET OF DENTURES?,I WAS WONDERING IF THE SPYDER CHASSIS MAY NOT BE AS RIGID AS THE LOTUS UNIT,HAVE CHECKED THE BODY FIXINGS AND DASH FIXINGS ALL SEEMS FINE,ANY EXPERIENCES PLEASE THANKS PHIL

[AHM]

Hi Phil,

I'll start by saying I know nothing about Plus 2s or Spyder! Except that at the time these cars were built Lotus were several times World Champions and renound for producing cars that handled well. Spyder have a long reputation for producing good products for Elans. So I suspect Lotus V Spyder isn't your issue.

You have bought all of the "right bits" but may I ask what you were trying to achieve? have you adjusted your adjustments in an attempt to achieve it?

Feel is subjective ... I have no idea what a loose set of dentures feels like! And what is "Tighter"? Do you have looses bits rattling around?... Assuming that you have set the car up to standard road car spec. my armchair guess is that your front springs are harder than standard with the possible addition of of poly bushes.


Simon

[Gray]

Hi

I think you will find Spyder chassis are torsionally more rigid than Lotus originals. Certainly mounting points, etc. are stronger. So I would think yor problem lies elsewhere.

regards Gray

[nebogipfel]

Can't comment on +2's or indeed spaceframes but my S4 has one of the original Spyder stressed skin frames and it is a much better designed and stronger structure than the equivalent Lotus chassis.

[Mark B]

The torsional rigidity of the spyder chassis is over 50% higher than the lotus original. I would look at the rest of the car as there are so many things it could be if the car does genuinly not feel right, bushes, balljoints, steering rack, tyres, geometry, springrates, wishbone alignment etc etc all play an equal part in how the car will feel and drive....

[bigvalvehead]

Hi All
Does anyone have any torsional rigidity figures for std chassis and 26R type reinforced chassis?
Cheers
dave
26-R-9

[gerrym]

Have you had the car up on a hoist? Could you see what felt was used between body and chassis?

Some folks have reported using neoprene instead of jute - can lead to poor NVH.


Just another bit to add to the list

Regards
Gerry

[p.faurie]

THANKS FOR YOUR INPUT GUYS,SEEMS I HAVE TO LOOK ELSEWHERE,PROBERLY SPRING RATES? THANKS AGAIN PHIL

[nebogipfel]

Have you had the car up on a hoist? Could you see what felt was used between body and chassis?

Some folks have reported using neoprene instead of jute - can lead to poor NVH.

Regards
Gerry

I'm having one of my frequent senior moments ........ what's NVH?

and Phil, WHY ARE YOU SHOUTING?

[john.p.clegg]

I'll guess

noise,vibration,harshness?


John

[nebogipfel]

I'll guess

noise,vibration,harshness?


John

I suppose that's a possibility but Gerry says "poor NVH" .....why would you want good noise vibration and harshness?

[p.faurie]

SORRY ABOUT THE WRITING JOHN IVE ALWAYS HAD A PROBLEM,IM LEFT HANDED.phil

[cabc26b]

Dave,

I have seen the standard chassis listed at 4500 ft/lbs per degree - I have never seen a number for a 26R modified chassis. For comparison the same reference has the lotus 79 formula one car with a torsional stiffness of 5000 ft/lbs per degree which would be less that what spyder claims for their frame.

As an aside I have never understood the justification in sacrificing the originality of the car by substituting a spyder frame nor have i seen the claimed improvements manifest themselves in lap-times.

George

[nebogipfel]

Dave,
As an aside I have never understood the justification in sacrificing the originality of the car by substituting a spyder frame nor have i seen the claimed improvements manifest themselves in lap-times.

George

I can't comment on lap times but I suspect there isn't likely to be any difference with the same suspension setup. I also don't think there is any doubt that the standard stressed skin Elan chassis had some significant design flaws. They have always had a tendency to stress cracking (which suggests that the frame flexes under load) The front uprights with built in mud traps are a poor design and the fixed cross member can also be a pain. In the past I had an Elan which had cracked on a front turret and also near the engine mounting.

If you sit the Spyder unit (as was fitted to my car when I bought it) alongside the Lotus original, the Spyder is clearly a stronger and better thought out design. It was of course designed with the benefit of hindsight because they had seen the problems with the original chassis design.

I've never looked closely at the Spyder spaceframes but suspect they are also well thought out and built.

I take you point about originality and it is important to me but if I needed a new chassis (Unlikely because mine although obviously far from new was still as good as new when blasted and painted) I would be tempted to go Spyder again.

[cabc26b]

I also don't think there is any doubt that the standard stressed skin Elan chassis had some significant design flaws. They have always had a tendency to stress cracking (which suggests that the frame flexes under load)

Relative to contemporary thinking the design principles were brilliant - Forcing the execution into lotus economics is a different matter and more likley a source of the failures you note than design ( material spec, production capabilities etc.) . I think the spyder argument is at best, opinion -