Lotus Elan

Suspension Tweaking

PostPost by: type26owner » Fri May 20, 2005 8:35 pm

Hey Robb,
Measured the front springs as having 17 coils with a wire diameter of .35". The rear is 11 coils x .415". Tough to get the tips of the calipers between the front spring coils to measure since the gap is more than a 1/4". DBE lists those spring rates as being 115 lb/inch for the front and 95 for the rear.

The front swaybar size you want is a 13/16" one. Dave Bean lectured me when I bought mine so you get one too. The bigger the bar the stiffer it is and the more stress it exerts on the bottom stud of the damper. That means the stud on the damper will break off sooner usually when you're flying around a corner. When it does the car will go into a snap oversteer which you will not be able to recover from. The dampers should be replaced more frequently so the stud does not fatigue fail and crack off in the first place. Trouble is there is no set time just how long your nerves hold out.
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PostPost by: robb4100 » Sun May 22, 2005 2:56 pm

Hey Keith,


Sorry for the long delay- had other commitments the last couple of days.


On Mine the Fronts are 3/8" (cheap calipers)and 15 coils. The rear are also 3/8" and have 11 coils.

I am heeding your warning in the Bean lecture and if you recall I do not want to turn a nuisance into a safety hazard.


snap oversteer which you will not be able to recover from


I remember that you suggested there were three general setups- standard (for the ladies- and maybe me :( for now), midway and track. Given my current level of mechanical skills (modest, former plumber, not a teen age gearhead ), and my relative unfamiliarity with the lotus, have had it for less than a year ( I do not know how worn the dampers are), It may make the most sense to try to return it to close to a standard setup, namely getting the ride height back to specs and see if the tire rubbing goes away.

Once that is done and I am more familiar with every thing we can look at attaining that midway tweaking. Does this make sense?

My goal is to keep the car handling well and safely. I do not have access to Trackdays so it is used on the back roads and highways of New England. Lots of bumps, ruts and other stuff to put stress on Dampers.

With regard to the standard setup the manual says the ride height should be 6" is that measured from the bottom of the chassis or from the rocker panels? Is the car is raised by compressing the springs? I also noticed that when I press down on the car above the wheel it easesback up more slowly than a modern sedan (more of a bounce), Is that normal?

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PostPost by: twincamman » Sun May 22, 2005 8:29 pm

Kieth----set my front end again again still wrong--then I remembered the front and rear wishbones are all hiem joints at the inner and outer pick up points :huh: _ -----DOH ----- its set up from the chassis out like a formula car [ a real one not a vee] -- I will have to set the plank height too :lol: - ed
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PostPost by: type26owner » Mon May 23, 2005 1:30 pm

Robb,
Your springs are an odd lot. Since they are quite inexpensive I'd buy four more at known spring rates when the time comes you want to improve the handling. You definitely should take things in an order that makes sense to you. These cars are getting rather old and to flog it without going through the suspension carefully and returning all the components to 100% condition is just asking for a big moment. The thing that gets you way ahead though is someone has already has done the upgrade to the smaller diameter springs and adjustable spring perches on the rear struts. That's got to be around 40 hours of effort to do that modification alone.

The manual is a bit confusing here. It's to the bottom of the chassis BELOW the fulcrums on the front. At the rear it's to the bottom edges of the U-shaped chassis beam. The original tires were 23" diamater so if the tires you're going to run are smaller subtract half the difference in the diameters from the ride height to compensate.

The springs are only compressed by the load. When you raise the ride height by spring perches the load does not change. The spring is still the same compressed lenght just the damper are extended more and the body reides higher.

Adjusting the damper is a bit of the black art and more than I'm willing to cover here. Suggest you read Carroll Smith's Tune To Win and Drive To Win for that info. I will say the dampers are extremely important in controlling rate of the body roll. The Spax which are only adjustable in rebound would not seem to play a roll. Well they do in the sense that the inboard suspension when cornering extends usually to the full droop position. Slowing that extension down softens the impact of the outboard suspension compressing it's springs and hitting the bumpstops. It gets complicated from here because all these adjustments are compromises since they affect one another.

Having the car respond well at all times like a go-kart is the only reason I own an Elan.

p.s. Found the countershaft in my gearbox was toast. Good thing I didn't wait to take it apart because the bearing surfaces of the gear were still okay. Whew!
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PostPost by: type26owner » Mon May 23, 2005 1:42 pm

Hey Ed,
I'm still green with envy so don't rub it in too much. I had my chance to own a 26R back in 1970. Steve Griswold had a red one in his shop that the customer stiffed him on the bill so he wanted just $3500 for it at that time. I kick myself in the butt everytime I think about it. :angry:

Have fun with yours!
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PostPost by: twincamman » Tue May 24, 2005 2:42 am

KIETH -- had a minor smoker today behind the dash-- the diff temp gauge sending lead went to ground on the heater---good thing I installed a master off switch on the dash---a very near thing :angry: --ed
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