Anti-roll bar polybushes

[Ekku 41]

I had a track day with my Esprit a week ago. I noticed heavy vibration to the steering wheel under heavy braking. In street with light braking this did not occur. I have also had some vibration similar to unbalanced wheels on regular driving. 

After track day me and my mechanic friend did sort of yearly service to the car and changed the Anti-roll bar bushes to the polyurethane ones which I had bought earlier. 

It had a huge impact on cars driving behaviour. Steering is now go-kart precise and the vibration is gone. 

It is hard to believe how much improvement can be had for so little work and cost.

[drdoom 399]

10 hours ago, Ekku said:

I had a track day with my Esprit a week ago. I noticed heavy vibration to the steering wheel under heavy braking. In street with light braking this did not occur. I have also had some vibration similar to unbalanced wheels on regular driving. 

After track day me and my mechanic friend did sort of yearly service to the car and changed the Anti-roll bar bushes to the polyurethane ones which I had bought earlier. 

It had a huge impact on cars driving behaviour. Steering is now go-kart precise and the vibration is gone. 

It is hard to believe how much improvement can be had for so little work and cost.

 . . . . because it is a Lotus it is a car of the most sensitive chassis characteristics and that is why we are mad for them!

Cheers

[AndyPG 50]

On 31/08/2020 at 08:48, Ekku said:

me and my mechanic friend did sort of yearly service to the car and changed the Anti-roll bar bushes to the polyurethane ones

Hi Esa,

I'm interested to know, did you change the ARB bushes at the link arms or the ones which saddle clamp to the sub frame?

Or maybe all four?

Andy.

[Ekku 41]

No, only the Anti-roll bar bushes. I am considering now to change the rest, but I am not sure if that is necessary or beneficial considering the street driving. Opinions welcomed. 

[andydclements 754]

If they are original bushes then at nearly 30 years old they are probably not anywhere near as good as they were back in 1998, same is probably true if they are even half that age, that would be my argument for replacing them. I'd only recommend replacing with the Lotus designed poly bushes since those were designed to give the car the handling characteristics of the original parts, not to make it harsher etc.

[AndyPG 50]

On 31/08/2020 at 08:48, Ekku said:

It had a huge impact on cars driving behaviour.

Hi Esa,

With the vibration now cured, it sounds like your old ARB bushes were the issue.

It would be well worth checking the front geometry now though.

The front suspension may have been adjusted a few times over the years with the deteriorating front bushes in place.

Now you have new poly bushes installed, the front geometry will likely have altered.

Unknown caster and toe alteration may be contributing to the new "go cart" like feel which may not be entirely a good sign.

Regards,

Andy.

[Ekku 41]

I have booked the time for geometry check. I had it checked 2 years ago, but better to be sure everything is In order. 

[AndyPG 50]

Nice one.

I'll be interested to know if the geometry has altered.

Andy.

Edited September 2, 2020 by AndyPG

[andyblackman777 39]

I doubt that the anti roll bar bushes would affect the geometry.