Lotus Elan

Rear anti-roll bar?

PostPost by: elansprint71 » Wed Jul 11, 2007 9:57 pm

Any opinions, based upon experience, of fitting an anti-roll bar to the rear of a +0? I've got Spyder chassis, Spyder twin wishbone rear, Susan Miller drive shafts, TTR adjustable springs and shox but can't help feeling that the back end is rolling too much in slower corners. Apart from that it rides and handles like the cat's pyjamas. :twisted:
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PostPost by: garyeanderson » Thu Jul 12, 2007 1:14 am

What is the front anti-roll bar diameter? larger than stock?

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PostPost by: elansprint71 » Thu Jul 12, 2007 6:56 am

Gary,
It's just the usual piece of 35 year old bent wire fitted by the factory. :)
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PostPost by: garyeanderson » Thu Jul 12, 2007 7:58 am

I would suguest a larger 7/8" bar in the front(not sure Addco still have one available, I think Tony Thompson offers a couple larger versions) before you venture to any rear bar.
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PostPost by: msd1107 » Thu Jul 12, 2007 4:42 pm

The wishbone rear suspension should get you some what better cornering performance compared with the standard struts. That is probably why you are noticing more roll in corners.

Spyder offers larger front bars, as does TT as mentioned by Gary.

Although, in theory, with the higher cornering limits allowed by modern tires would suggest larger front anti-roll bars and a small rear anti-roll bar, many people seem to live without a rear one.

I would opine that you would see higher steady state cornering g's with a rear bar, but would notice more transient over steer.

If you got the adjustable a-arms, you probably could get everything set up to go with the rear bar and a proper front bar.

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PostPost by: frearther » Thu Jul 12, 2007 4:49 pm

I agree with Gary - a stiffer front bar is a MUST when fitting a rear bar. If you don't do this, the handling can become SCARY. Believe me, you don't want to experience it at any kind of speed when driving in anger.

Also, the ride will be very much stiffer. If you're happy with the standard setup, leave it that way. I went back to original anti-roll bar setup when I stopped autocrossing.
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PostPost by: paros » Sat Jul 14, 2007 6:33 pm

Try increasing the rear shox - the rebound rate seems to have a significant effect on the unloaded wheel and thus reduces roll withour going to the 'bad news' of a rear roll bar.
I used to race a GT car based on an Elan and even with these mods [ Ralt raer suspebnsion ] the rear roll bar was a minor tuning aid rather than a means of controling rate of roll.
On the more normal Elan I race now, I ignore the rear by and large, and would go along with a stiffer front bar - Pat Thomas does a hollow one by the way and see what happens. In fact I would go for stiffer rear springs if dampers and front roll bar don't do the trick, rather than a rear roll bar.
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PostPost by: frearther » Sat Jul 14, 2007 7:52 pm

The reason I added the rear bar was to help keep the inside wheel more firmly on the ground without making the rear shocks harder (for autocrossing). This succeeded, but the heavier (hollow) front bar was then required to keep the front and rear ends in balance. I'm sure that cranking up the Konis would have given me a similar result, but this was also my (weekend) road car, too, and I was attempting to keep the ride on the bearable side. That sort of happened :roll:
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PostPost by: elansprint71 » Thu Jul 19, 2007 8:48 pm

Thanks for the opinions guys, keep 'en comin'. :P

Cheers,
Pete.
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PostPost by: OregonBriton » Sun May 26, 2013 1:15 am

Greetings, all -
Just joined the forum, although I've had my '69 / 70 Elan S4SE FHC since 1973. It came as a kit from the London Sports Car Centre, and I knew the first owner well. It has lived in Portland, Oregon for decades now, as have I - much easier on the chassis and ferrous components, rust and corrosion-wise.
This anti roll bar at the back topic is of interest as I'm considering a CVJ drive shaft conversion, and this must change the rear anti-roll characteristics at least somewhat. One model shows the a/r contribution of the doughnuts to be 20-25% as great as the standard front a/r bar. Now, that won't amount to much of a bar at the back, but one wants to consider all aspects of any modification!
Any thoughts and input welcome.
Cheers,
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PostPost by: tract0rman49 » Sat Jun 15, 2013 9:18 pm

I have often pondered the wisdom of adding a rear Anti Roll Bar (Sway Bar to our US cousins) to my 71 Elan Sprint. I do have a much stonger 7/8" diameter front bar and stiffened suspension with Konis too. Couple of years ago fitted "Sue Millers Drive Shafts" kit to replace shot Rotoflexes. The car is great in the dry with outstanding grip on its 155x13 road rubber but in the wet its "scary".

The lack of Roto Flexes does make the car feel taughter though.

Would like to hear from members who have taken this step.
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