Factory Sport/Assesment day

[SADLOTUS]

Saw Mathews post and went to the factory today for their Sport/Assesment day. Good fun and informative. Had four mechanics/technicians looking over the car and then a test driver (who?d been there since 1966 and thought he?d probably driven my car new) take me around the track a few times..... then point out the car?s handling shortcomings


...anyone know of a suspension setup specialist in the SouthEast? ..or anywhere really if it?s worth it.

Ta verily
Paul

[reb53]

Be interested to know what the tester was generally finding wrong with old Elans.

Same sort of things all the time?
Any clever suggestions?

Ralph.

[john.p.clegg]

Yes,come on,give us the full story....

John

[SADLOTUS]

John, Ralph

The full story?... rang up the factory on Friday, got my email confirmation through and set off early on Saturday for a 10am start at Hethel. Straight in, no queues, no traffic, parked on the end of a line of Elises and Exiges. Mine was the oldest car there except for an Eclat (I think). One S4 and one +2 arrived later in the day. Signed in for the ?Vehicle Safety Check and Evaluation? the ?Inspection? and the ?Engineer Drive Evaluation?.

Up on the ramp the (young) techy- who builds racing 2-Elevens, sevices Elises etc during the week was a bit lost when it came to my ?older? car, so he called in Nick Adams - Lotus Chief engineer - to help. Nick was able to guide him on where to look for the weak spots, foibles and idiosyncrasies of our cars. He?s had a lot of Elans and raced a lot of Elans and won in a lot of Elans too. With the car up in the air he suggested a locking nut under the rollbar to shock absorber nylok nut, did a spanner check over the underside and helped with adjusting the front wheel bearing. Just over an hour was spent on the car, at one point with four techies, looking, adjusting and suggesting.

Overall, after a forty point check list I wasn?t unhappy with the things they found - bad earth on rear indicators - N/S/F brake hose just about rubbing on the steering rack (fitted a length of cable tidy/spiroflex stuff) - front wheel bearing play - those front antiroll bar nuts were tightened - a lower wishbone nut could have been tighter. We compared notes on modifications, him the seasoned, winning, Lotus Chief Engineer and me the Numpty Novice - Oh how we laughed at the handfuls of cash we?d given over to our hobby. The young Techy said he was really pleased to have gone over my car because usually it?s only ever the newer Lotus? that come to these days.

After this came the Engineer Drive Evaluation - I was hoping and I hope Nick was hoping, that he?d take me round the Hethal track, but minutes before we were due to go out he ricked his back - enough to have an ambulance called! - (No privacy on the world wide web eh!) Another young driver/engineer was to take his place but suggested Alister McQueen who was visiting for the day would be more beneficial. Alister said he?d been a test engineer and instructor at Lotus since 1966 and if my car wasn?t a kit would probably have driven it after it?s build in 68.

After signing the indemnity and collecting our Lotus supplied open face crash hats, Alister and I made ourselves comfy - odd to be the passenger in your own car - a steady but not slow first lap to get to remind himself of the Elan then a few flying laps. At the end of lap two we took a ride around the circle at one end, Alister pushing the car wide - full understeer then lift off oversteer - Alister said Lotus cars have always been designed to make the driver feel confident immediatly, but he wasn?t feeling that 100% from mine. His notes read: ?diagonal pitching - feels nose down during cornering -low front rebound damping -check rear toe?. I understood what he meant, perhaps I?d just got used to it. what I also noticed - as a passenger - was a bouncy rear from the corner under compression - suggestions? I was thinking maybe my bumpstops are too small (which they are) - maybe? What I also thought about as a passenger was how much pressure I put on the door and hoping I?d put the door locks together as well as I hoped I had! Four laps in all with Elises going round at the same time, nice to feel the car on a track again, it's been a long time.

All in all a really good day, rounded off by Classic Team Lotus testing the 79 there as well.

[reb53]

Thanks for taking the time to write that up Paul.
Very interesting.

Cheers
Ralph.

[john.p.clegg]

Paul

Nice one.thanks.

P.S. were the elises passing you or you passing the elises?

John

[steveww]

Having the correct rear bump stops makes a big difference. Try changing the damper rates.

[ppnelan]

Paul, nice write-up. Looks like you were a good representative for the classic Elan amongst the Eli-ges! Glad you had a good time.

I remember the 'ceiling-effect' F1 car 'shell' in the background of your first photo from the open day - one better than 'ground-effect'...

Did they say there was excess play in the front wheel bearings? Always tricky to get right, as it feels perfect until you put the wheel on...

Matthew

[elansprint71]

Having the correct rear bump stops makes a big difference. Try changing the damper rates.

Steve,
Don't understand this bit; doesn't the bump-stop only come into play when you have used up all your suspension travel i.e. to stop the suspension crashing through pot-holes, etc? I would not have thought it was part of even extreme cornering manouvres(sp?). Am I missing something?

[tdafforn]

Interesting...
Since fitting new rear shocks I have always felt the rear of my +2 "hops" a bit on corners..
Is this a bump/rebound issue?
Tim

[rgh0]

The original Aeon type 505 rubber spring in the rear suspension was much more than a bump stop. It came into play with relatively little rear suspension travel of about 1.5 inches of bump and acted to give a progressive spring rate in cornering that balanced the front and rear of the car. Full bump travel is about 3 inches. If you dont have this rubber spring or if it is deteriorated then the car will have some interesting handling characterisitics as you get it sitting down to far on its outside rear wheel as the suspension loads up in a corner. This can lead to a sudden oversteer in the extreme that further transfers load to the outside rear wheel due to the side loads all being carried on this wheel as you steer into the slide and can ultimately lead to the car rolling if this extremely heavily loaded wheel trips on something like a piece of rough road or curbing.

cheers
Rohan

[SADLOTUS]

Hi all, like most things on this site we've discussed this before...
post93187.html?hilit=%20bumpstop#p93187
Steve, you recommended the powerflex SAF005 which was advice I meant to follow, but like a lot of things...I failed to follow. Steve, did you ever add a spacer? I intend order a set this week and give them a try, the little conical shorties on the car now hardly compress at all and I can see how the sudden lack of suspension movement can lead to interesting handling. Going on an airfield track/test day thingy at North Weald soon so will let you know what happens then.

Rohan, it's interesting to know how little movement there is before the bumpstop comes into play - as you say it's more of a suplementary spring - in fact that's how powerflex market their bumpstops. When you say 'Full bump travel is about 3 inches' do you mean the original Aeon bump will compress from its full length of 5ins down to 2 giving 3 inches of bump travel?

Anybody understand the little graphs on the Powerflex site showing Force and Deflection?

http://www.powerflex.co.uk/products/Spe ... 141/1.html

http://www.powerflex.co.uk/i/product_im ... ochure.pdf

Thinking back to the test track at those fast suspension loaded bends - it was just like a solid rubber bounce, which is what I would expect from the 50mm solid shorties I have now.

[steveww]

Currently no additional spacer added, just running the Powerflex at the moment. Partly due to not having time to play with different suspension settings and that I do feel anything is wrong with this set up. Adding some spacers would "firm" up the rear a touch and give a bit more oversteer.

[rgh0]

Design clearance between the top of the strut and bump stop was around 1.5 to 2 inches at normal ride height. Quoted Bump travel is around 3 inches from the rear suspension diagram in the manual. This gives around 1 to 1.5 inch of compression if the Aeon spring at full bump travel.

cheers
Rohan

[cabc26b]

Paul and Steve ,

what spring rates are you running front and rear ? also if you don't mind, what thickness of front anti-roll bar. If your set ups are close to mine then I might want to make a change while the car is not quite together.

Thanks

George