Lotus Elan

Front Lower Wishbone and steering tie rods

PostPost by: richard sprint » Tue Apr 02, 2019 7:53 pm

I've fitted the 'fast road' front springs and dampers (from Tony Thompson) which has lowered the ride height by approx 1 and a 1/2" (40mm) and have a few questions:

1) The lower wishbone is now at a reverse angle i.e. instead of being approx. horizontal with the chassis beam it now sits at approx 15/20o above the chassis, the same applies to the steering tie rods. Will this affect the steering in anyway through out it's range of operation?

2) Will the angle of the lower wishbone have any effect on the lower wishbone bush? the reason I ask is that the front bush has become detached from its mounting tube causing the lower front wishbone to move back toward the chassis beam

3) i.e. by lowering the front of the car is this causing a stress point on the lower wishbone bush?

I'm wondering whether I should have received an information sheet covering the setting up of the ride height of the springs via a C spanner and whether this adjustment would then raise the height of the car to nearer original spec.....

I look forward to receiving some learned thoughts!

Thanks in advance.
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PostPost by: 661 » Tue Apr 02, 2019 8:52 pm

I would run standard wishbones at near horizontal. The road height may vary with different tyres.
I'd adjust the spring platforms to allow this to happen.
I'd perhaps run a small rake front to back, but not much, say 1/4" on a road car.

I'm not sure what you are describing with regard to the bush. A picture may be helpful. I assume that you have standard rubber bushes with the attached metal inset? This should not come adrift and should only be tightened once the car is at your desired height.
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PostPost by: webbslinger » Wed Apr 03, 2019 12:42 am

I just put TT shocks with 110# 11" springs on the front of my S4. My car is on the heavy side and I had to run the perch up 2" to get the a-arms parallel and keep 175 series tires from rubbing. Previously with 12" springs the perches were up 1".
I think you are going to be happy with them. The difference they've made on my car is amazing.
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PostPost by: john.p.clegg » Wed Apr 03, 2019 5:26 am

Richard

1 ) Yes.

Search on here for bump steer...

John :wink:
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PostPost by: richard sprint » Wed Apr 03, 2019 8:43 am

Thank you gents for your advice and suggestions, the bump steer posts are enlightening.

Now awaiting the C spanner and setting up details from TTR...
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PostPost by: nmauduit » Wed Apr 03, 2019 8:46 am

was it your intention to lower the car by that much? the suspension is optimized for operation near the point where the triangle is horizontal, as mentioned above if you want to operate it around a different point, you may need to tune it for that point (possibly with an end result not as good as the original setting)

as for the rubber bushes, they should not be under tension all the time : it is recommended to tighten them at the resting position of the loaded car (if you intend to keep your car lowered, you should undo the nuts to free the suspension from the preload resulting of the new springs, and retighten them at the new resting position).
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