Lotus Elan

Spyder or 26R Chassis

PostPost by: stevebroad » Mon Oct 22, 2012 10:20 am

Spyder chassis' seem to be very popular, but I have heard mixed reviews about them. Tony Thompson from TTR hates them and claims many people have come to him for a replacement chassis as they reckon the Spyder ruined the handling. The double wishbone rear suspension has also been critcised due to the top wishbone being aligned, allegedly, the wrong way (the outer mounting point being lower than the inner one) - Is this correct?

Are they better than a standard chassis modifed to 26R spec? If so, in what way(s)?
stevebroad
Fourth Gear
Fourth Gear
 
Posts: 921
Joined: 08 Mar 2004
Location: Essex, England

PostPost by: rgh0 » Mon Oct 22, 2012 10:31 am

The spyder chassis is better from maintenance access and corrosion life and dimensional accuracy in my opinion.
The stiffness compared to the standard chassis is better in the plus 2 at least and I can fell the difference, not sure if its signficant and you feel it in an Elan ( and I cant feel it in the Elans with spyder chassis I have driven compared to my standard chassis car)

I dont like the Spyder wishbone rear suspension and would stay with the standard Lotus struts if using a Spyder chassis which they are designed to also accomodate.

It is not legal for historic racing in Australia at least so only relevant for a road car.

cheers
Rohan
User avatar
rgh0
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 7491
Joined: 22 Sep 2003
Location: Melbourne, Australia

PostPost by: Tahoe » Mon Oct 22, 2012 8:27 pm

Interesting, as my car came with the Spyder chassis and double wishbones. I had never heard that there was a possible issue with geometry. I know I haven't driven it much compared to others, but on my car anyway it seems to handle very well. If anyone has any more info I'd appreciate it. I have the original struts that need rebuilding which I could put back on in the future if it is an issue.
Tahoe
Fourth Gear
Fourth Gear
 
Posts: 687
Joined: 19 Sep 2010

PostPost by: stevebroad » Mon Oct 22, 2012 9:22 pm

Tahoe wrote:Interesting, as my car came with the Spyder chassis and double wishbones. I had never heard that there was a possible issue with geometry. I know I haven't driven it much compared to others, but on my car anyway it seems to handle very well. If anyone has any more info I'd appreciate it. I have the original struts that need rebuilding which I could put back on in the future if it is an issue.


Next time you are under the rear, compare the top wishbone mounting points. The chassis pickup point should be lower than the outer joint. This geometry pulls the top of the outer wheel in on a corner helping to keep the tread in contact with the road.
stevebroad
Fourth Gear
Fourth Gear
 
Posts: 921
Joined: 08 Mar 2004
Location: Essex, England

PostPost by: Tahoe » Thu Oct 25, 2012 8:29 pm

stevebroad wrote:
Tahoe wrote:Interesting, as my car came with the Spyder chassis and double wishbones. I had never heard that there was a possible issue with geometry. I know I haven't driven it much compared to others, but on my car anyway it seems to handle very well. If anyone has any more info I'd appreciate it. I have the original struts that need rebuilding which I could put back on in the future if it is an issue.


Next time you are under the rear, compare the top wishbone mounting points. The chassis pickup point should be lower than the outer joint. This geometry pulls the top of the outer wheel in on a corner helping to keep the tread in contact with the road.


I'll look and maybe do some kinematic analysis. It's not definitive that the geometry should be a certain way. It all depends on the pivot points and there relationship to each other. Roll center etc. is all affected and without laying it all out to see how they interact it can't be said that location is not correct. On the other hand maybe it's not correct and Spyder screwed up big time. :oops:
Tahoe
Fourth Gear
Fourth Gear
 
Posts: 687
Joined: 19 Sep 2010

PostPost by: gav » Thu Oct 25, 2012 9:05 pm

Mine seems to handle fine - and I have a handbrake that works on hills.........
One day I'll actually finish - completely - one day....
User avatar
gav
Third Gear
Third Gear
 
Posts: 464
Joined: 26 Jan 2004
Location: Hertfordshire UK

PostPost by: stevebroad » Thu Oct 25, 2012 9:16 pm

gav wrote:Mine seems to handle fine - and I have a handbrake that works on hills.........


Handbrake works? Well, it's not a real Elan anymore now, is it? -)
stevebroad
Fourth Gear
Fourth Gear
 
Posts: 921
Joined: 08 Mar 2004
Location: Essex, England

PostPost by: stevebroad » Thu Oct 25, 2012 9:27 pm

Tahoe wrote:I'll look and maybe do some kinematic analysis. It's not definitive that the geometry should be a certain way. It all depends on the pivot points and there relationship to each other. Roll center etc. is all affected and without laying it all out to see how they interact it can't be said that location is not correct. On the other hand maybe it's not correct and Spyder screwed up big time. :oops:


I don't think the pivot point makes any difference. If the top wishbone is angled down towards the wheel (outer bush lower than inner one), when the body drops that side in a corner the wishbone will move towards the horizontal pushing the top of the wheel outwards, increasing positive camber. If the wishbone starts with the outer end above horizontal the same body movement will shorten its effective length and pull the top of the wheel in, increasing negative camber which helps to keep the outer wheel more upright in a corner.
stevebroad
Fourth Gear
Fourth Gear
 
Posts: 921
Joined: 08 Mar 2004
Location: Essex, England

PostPost by: gav » Thu Oct 25, 2012 9:31 pm

Chaps

The bottom wishbone points downwards at the wheel (approx 5 degs) and the top one points upwards.
Not sure what the perceived problem is - the rear wheel goes into neg camber as the car squats so that the contact patch is maximised.

Steve - there are a few Elan quirks that I can live without - a good handbrake is a boon if you live on a hill as I do....

Gavin
One day I'll actually finish - completely - one day....
User avatar
gav
Third Gear
Third Gear
 
Posts: 464
Joined: 26 Jan 2004
Location: Hertfordshire UK

PostPost by: stevebroad » Thu Oct 25, 2012 10:42 pm

gav wrote:Chaps

The bottom wishbone points downwards at the wheel (approx 5 degs) and the top one points upwards.
Not sure what the perceived problem is - the rear wheel goes into neg camber as the car squats so that the contact patch is maximised.

Steve - there are a few Elan quirks that I can live without - a good handbrake is a boon if you live on a hill as I do....

Gavin


Yes, that should work.

Mine only worked at the yearly test. It is now hydraulic in the rebuild so should work properly as long as there are no leaks :-)
stevebroad
Fourth Gear
Fourth Gear
 
Posts: 921
Joined: 08 Mar 2004
Location: Essex, England

PostPost by: pauljones » Tue Oct 30, 2012 5:57 pm

Steve

If its of any use to you, my chassis is near Portsmouth. If its any where near you then feel free to call me and you pop in and measure till your hearts content.

Paul
Kick the tyres and light them fires...!!!!!!!
pauljones
Fourth Gear
Fourth Gear
 
Posts: 968
Joined: 09 Feb 2008
Location: Gosport sur la mer,South hants

Total Online:

Users browsing this forum: stevebroad and 7 guests