Evora ARB Bushes

[Scotsdave]

Hi Guys,

I know our cars are known for going through arb bushes and there seemed to be no solution other than to replace them frequently. Well it would appear the Americans have developed a poly bush to replace them with!

Hopefully they are a fit and forget solution. Link here

I wish I had found these a few months ago as I've only just replaced mine with the standard Lotus Rubber bushings

Are any of the UK suppliers such as Elise parts etc not offering a solution to this?

Cheers

David

 

Actually scratch the above it appears Powerflex now make bushes for the Evora. I emailed them last year and they said they had no plans to make bushes for the Evora!

[Bravo73]

ISTR that the bushes will last better if they are installed properly (ie with a bit of the correct lubrication). 

 But you’re right - those ‘Hethelsport’ bushes are just Powerflex ones. I’m pretty sure that Powerflex is a UK company. 

[Scotsdave]

Yeah Powerflex are a UK company. I've used some of their bushes before on my M3 for the rear diff.

They last the life of the car and cost not much more than the OEM lotus bushes so I'll probably Upgrade to these at some point.

[Bruss]

I haven't tried the poly bushes but research and experience on other cars tell me that they give a harsher ride and possibly more noise due to the lack of flex compared to the oem. It will be interesting to hear from anyone who has them fitted. So far the cost to change them once a year or even  every 2 years if you do low mileages, doesn't seem excessive to me.

 

 

 

 

[Scotsdave]

I agree the cost isn't much but my car is a daily driver and the hassle of fitting them every year or every 2 years when I can fit something more durable just once for the life of the car is worth it to me.

I might upgrade to these in a few months to see if they are harsher or not.

[pete757]

9 hours ago, Bruss said:

I haven't tried the poly bushes but research and experience on other cars tell me that they give a harsher ride and possibly more noise due to the lack of flex compared to the oem.

Fitting Poly Bushes to an ARB will make no difference to 'ride', they won't make it harsher.

The difference you 'may' feel (it will be tiny) will be a crisper turn in on corners as the ARB takes up torsional load without the normal bush's 'softness'. If I was replacing mine, I would go with the poly bushes.  

[Bruss]

You can buy arb bushes made from anything from bronze to rubber. They will have an effect on how harsh the steering feels. I would argue that it also effects how you feel the 'ride' as steering feedback is a major part of that feel, but I admit it is subjective. Pays your money and takes your choice. Incidentally Lotus have continuously 'improved' the arb bushes over the lifetime of the Evora. Quite what grade of material they are currently using I don't know. Also as said I suspect the Hethel ones are these

https://www.powerflex.co.uk/road-series/products/Evora+(2010+on)-3458/1.html

 

 

 

 

 

 

[Bruss]

Just to add for anyone that wants to understand the function of the ARB.  It is a part of the suspension not a part of the steering. although that's where most people may feel it. The ARB acts to stabilise and control the rate of movement of the suspension laterally across the car. ie. In a straight line if the right wheel hits a bump and the left wheel is still on the flat then the arb limits the speed at which the two suspension units act against each other.  The bushes that hold the arb in place allow the bar to twist in its fixings.  When cornering those lateral forces are generally higher and that's why you feel it more in a corner as the arb acts to keep the suspension units from moving too quickly and allowing the wheel to come off the ground. The bush as well as allowing that free twist movement also now acts as a damper for vertical movement through the fixings and eventually transmitted through chassis. Hence the knock over bumps of a worn bush.

 

 

[EGTE]

Great explanation. Are the Lotus ones much more expensive, does anyone know? 

I've heard variable reports about Powerflex bushings, but I suspect a lot of that is down to poor fitting/lubrication, to be honest.

[pete757]

Just to clarify Bruss's comments...

ARB's are designed into the cars 'suspension'... but for handling/steering reasons... to manage lateral weight transfer loading during cornering and hence manage/mitigate either oversteer or understeer depending whether you go for a stiffer ARB either on the front or rear.  Hence an ARB should indeed be classified as a handling/steering aid, not a suspension aid. 

They are not designed from the outset to manage the suspension movement on 'bumps', though of course there presence will indeed effect that as Bruss has explained.

The clunking from worn bushes tends to originate from the 'drop links' from the ARB's to the wishbones, rather than from the 2 'saddle' fittings with bushes that bolt the ARB to the chassis. These are where the harder 'power flex' bushes are installed that will give an improvement/response to steering input, as the ARB twists without any transmission loss of that torque into the softer bush.   

https://www.powerflex.co.uk/road-series/products/Anti+Roll+Bar+Bushes-2789/1.html

All good stuff eh! 😉

 

[EGTE]

Anyone know what size ARB bushes to order for an S1 NA?

Thanks.

[agentdr8]

24 minutes ago, EGTE said:

Anyone know what size ARB bushes to order for an S1 NA?

Thanks.

23mm in the front, 21mm in the rear.

[EGTE]

Many thanks, Dave. 

[EGTE]

https://www.powerflex.co.uk/road-series/products/Evora+(2010+on)-3458/1.html

[p4cks]

Apologies for the bump, but I've invested in a set of these having had a second set of standard ARB bushes fail in nearly two years on my Evora (1,500 miles of very light driving)

Will let you know how I get on.

[Cdm2018]

2 hours ago, p4cks said:

Apologies for the bump, but I've invested in a set of these having had a second set of standard ARB bushes fail in nearly two years on my Evora (1,500 miles of very light driving)

Will let you know how I get on.

Be interested to see how better these powerflex ones , I just had my front changed two weeks ago to OEM and now wished I asked or supplier the power flex ones but was confused about the colour coded options (black or purple) 

anyway it’s done now so will see in the next year, especially as the last ones only lasted one year and 7k ! Ridiculous

i wonder what guarantee I get from my lotus dealer on the OEM part ??? 

[agentdr8]

3 hours ago, Cdm2018 said:

Be interested to see how better these powerflex ones , I just had my front changed two weeks ago to OEM and now wished I asked or supplier the power flex ones but was confused about the colour coded options (black or purple) 

anyway it’s done now so will see in the next year, especially as the last ones only lasted one year and 7k ! Ridiculous

i wonder what guarantee I get from my lotus dealer on the OEM part ??? 

I finally got around to installing my Powerflex Performance ARBs and I definitely believe they'll last a lot longer than the OEM ones. Not that the OEMs are really soft or squishy, but the Powerflex ones are 80A hardness. I have noticed a slight increase in NVH, but I'd say it's less than 10% over OEM. I'm sure the Race ones at 95A would make for a significantly harsher ride. 

I had gone through 2 sets of OEM ARBs in under 3 years. Maybe a total of 15k mi. 

[Cdm2018]

Dam

i made a silly mistake should have asked for power flex ones to be fitted if they don’t make a huge difference to harshness of the ride etc ? 

I will have to bear in mind but If history tells us I guess I will be changing in 12 months time ? 

[p4cks]

In my experience, you'd be lucky to get 12 months out of the Lotus ones

[Cdm2018]

48 minutes ago, p4cks said:

In my experience, you'd be lucky to get 12 months out of the Lotus ones

You might be spot on but my bushes were almost making knocking noise from two weeks after they were supposed to have been replaced ???? 

[p4cks]

Mine too!

[Bruss]

I drive my car hard on track and don't have the same problem with these. I did have one set replaced on my first Evora by Lotus at a regular service. After that I have cleaned and greased them at every service interval and have replaced them at 10k as a 'just in case' service item. Standard Lotus ones so far. 

[Cdm2018]

I don’t know how easy is it to clean and grease to a non mechanic like me ?

however if reading the comments on powerflex bushes these look like a more long term solution ? 

Anythjng to stop that annoying knocking sound is the aim ! 

[Bruss]

Are you sure its the arb bushes clonking?

Very easy to clean and grease. Two bolts to remove the horseshoe retainer clamp thingy. Slip the bush along the bar, or even slip it off, clean the bar, apply grease, two bolts to put the horseshoe clamp back on. The aim is to stop the bar collecting water under the bush and going rusty. The rusty bar is what wears the bush too quickly.

 

[Scotsdave]

I agree to an extent that greasing the standard bushes aren't too hard to do but who wants to jack up the car, remove the undertray and undo the ARB every 6 months/1yr depending on usage.

I fitted the powerflex bushes at the end of December with brand new droplinks at the same time as my car had hit 55k and it is used daily. The ride isn't any harsher and I don't need to worry about the bushes any more.