Author Topic: Spring Rates  (Read 4415 times)

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Offline EuropaTC

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Re: Spring Rates
« Reply #15 on: Thursday,August 14, 2014, 10:53:35 AM »
Thanks for the kind words and encouragement folks.

I've been out twice today, essential road testing as I explained to my wife...   ;)

The first time was with the dampers at "0" to see what it felt like with the minimum setting.  Then after getting back, setting the front tracking (because I'd forgotten to) I adjusted the dampers to roughly half way settings. For anyone considering these dampers they have a knurled adjuster that is simple to move with your fingers and have 13 clicks, so I set them to 6 for now.

Back out on the same roads and honest guys, even with my rose-tinted specs on, it's transformed.  My roads are a mixture of country lane, one very bad pot-holed section and what passes for smooth "A" roads in Lincolnshire, so a very good cross section of driving conditions.  I've stripped the old units this afternoon and it's not a case of comparing new with worn out old stuff, all 4 dampers are still working with no leaks. And we know springs may sag but the rates stay constant, so it is a reasonably fair comparison of new modification vs standard spec.

When you say "250/140lbs" spring rates compared to OEM 116/75lbs you might think it's going to be harsh, but not so and I think I could have gone to even higher suspension frequencies both front & rear. Ok, I'm not a fast driver, but on these roads at between 60-70mph it seems quite stable to me, so I'm sure the track guys on here would be calling it "tame".

No problems so far with ride height so unless things change I shall stick with it. If so, then I'll look at making new roll bar mounts.I can't see why it shouldn't move upwards towards the body a touch and get the arms level again.

Brian
« Last Edit: Thursday,August 14, 2014, 01:10:39 PM by EuropaTC »

Offline Serge

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Re: Spring Rates
« Reply #16 on: Thursday,August 14, 2014, 11:39:36 AM »
Thanks for the update, Brian!

There's another option for mounting the ARB, and that's above the steering rack. You'll have to make new droplinks that connect to a longer lower shock bolt, but it looks to be feasable to me. I'll have to take some measurements and figure a droplink out when I have some time. It would move the entire ARB out of harms way.


Kind regards,

Serge

Offline 460384

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Re: Spring Rates
« Reply #17 on: Friday,September 04, 2015, 07:11:52 AM »
Below is what Ron, 2483R on the top mount sway bar..

Tom,

Installed an above mount sway bar some 15 years ago. The swaybar itself is an Addco, shortened about an inch on each end. This will allow you to pass it through the wheel well opening from one side to the other. I used an Addco simply because I already had it, and didn’t have to spend money/time for a new one.

You can shorten the stock links and use them. I didn’t want to because someday I may want to return to stock configuration and will need those links, and Lotus parts have a tendency to turn into unobtainium quickly.

The links are homemade. They are composed of a hex coupling nut bought at the local  hardware store, a length of pipe welded to one end, and a rod end which I bought from McMaster-Carr. The rod end does not have a bearing, it is just a threaded rod with a cylindrical shaped end.

Use the stock sway bar bushings. Using a bench grinder, turn the center of the bushing until its outside diameter corresponds to the inside diameter of the pipe. Leave the ends of the bushing the factory size. This will keep the bushing from slipping up/down the sway bar.

I had a machine shop drill and ream a bolt hole at the ends of the sway bar. Install a longer bolt at the bottom of the shock. Connect the swaybar and shock bolt with a length of threaded rod and 2 rod ends. I will try to find some pics of this and post them in the gallery.

Be advised that the stock swaybar does contribute some stiffness under wheel bump/drop. The ends of sway bar move from side to side in the horizontal plane. Using an above mount sway bar will eliminate its stiffness contribution, meaning that you will need stiffer springs to keep the same handling balance you had before. Also it will be difficult to get the sway bar around the stock diameter springs, you may need smaller diameter springs. So you will have to buy new springs.

An easier/cheaper way is to leave the sway bar below mount. Make a new link as before but use a long bolt instead of a coupling nut. Cut the hex head off the bolt on weld it to the pipe section. Use a real rod end with a bearing on the threaded end. Make new bushings as before. Adjust the length of the link (by turning the rod end on the threads) until the sway bar just touches the chassis closing plate. I used this system for many years prior to switching to an above mount system.

Ron
2483R
Tom/Colorado
460384 & 2141R