S2 Front Anti-roll bar

Candellara · Post by **Candellara** » Fri Aug 09, 2013 6:58 pm

Due to my car's history, i've a solidly mounted (& very thick) adjustable front anti-roll bar connected solidly via adjustable rose jointed drop links.

Times have moved on in 25 years and this set up is very jarring on the road. I need to move to something that hints at the car's race history but also makes it alot more compliant on todays potholed roads.

Suggestions please. Can anyone recommend a comple "fast road" maybe poly mounted solution inc drop links?

Candellara · Post by **Candellara** » Mon Mar 17, 2014 10:07 am

Thought i'd revive this thread.

I changed the solid anti roll bar mounts for heavy duty poly bushed items and the ride is a little better.

To rid myself of the "jarring" when traversing rough UK roads, i think i'll have to get rid of the solid rod ends and move to a bushed anti roll bar drop link.

Does anyone know if you can get polybushed adjustable drop links?

Candellara · Post by **Candellara** » Mon Mar 17, 2014 7:13 pm

To ensure that the ARB is causing the "clunk" from the front end which feeds straight back through the steering when running over potholes etc, i ran the car with the ARB disconnected - and the problem goes away.

Original set up was:

Heavy duty uprated torsion bars - retained
Solid rack mounts - removed in favour of polybushed items
Solid ARB Mounts - removed and replaced with V12 brackets & polybushed

It still remains that the adjustable ARB has no traditional drop links, but adjustable links with solid rod end bearings at each end - and i think this is causing the issue

Thoughts anyone?

JEP41 · Post by **JEP41** » Mon Mar 17, 2014 9:33 pm

When building my serirs 1 into a lightweight rep I installed Rob Beeres uprated Torsion bars and his uprated anti roll bar. After several journeys and track days I replaced the uprated ARB with the standard item but retained Robs Torsion bars and this appears to be a perfect combination for me. I also tried the polybush route but reverted to standard metalastic as giving the best feed back through the suspension.

Candellara · Post by **Candellara** » Tue Mar 18, 2014 11:19 am

Thanks John

Any particular reason for reverting to a standard ARB?

Jason

JEP41 · Post by **JEP41** » Tue Mar 18, 2014 12:07 pm

The reason for returning to the standard ARB was the feedback through the front suspension, I preferred the way the car cornered with the standard bar.

jag68 · Post by **jag68** » Fri Apr 04, 2014 6:52 am

Polyurethane bused threaded rod ends are available here: http://www.mcdonaldbrosracing.com.au/rods.html
and probably elsewhere.

Candellara · Post by **Candellara** » Fri Apr 04, 2014 8:37 am

Thanks

Candellara · Post by **Candellara** » Thu May 08, 2014 8:11 am

Hi Chaps

Still fighting this problem :?

When i traverse a bump in the road or a pothole, i'm getting a "clonk" which "i think" is coming from the lower bulkhead area.

Is it feasible that the reaction plate can cause such a noise? One thing is for sure - that the issue is better if i disconnect the solidly mounted front ARB

I'm scratching my head on this. I think that the solid ARB mounts are causing something else to "clonk" but my ARB is a "full race rosejointed set up" which i think i need to change for something more "fast road"

Can anyone recommend a good "adjustable" front ARB that uses the original drop links allbeit polybushed?

steve3.8 · Post by **steve3.8** » Thu May 08, 2014 8:24 am

Before you go stripping the reaction plate out check the front shock absorbers , they will give this symptom when knackered .

Steve

Candellara · Post by **Candellara** » Thu May 08, 2014 8:38 am

steve3.8 wrote:Before you go stripping the reaction plate out check the front shock absorbers , they will give this symptom when knackered .

Steve

Hi Steve,

Brand new shocks fitted. New upper & lower ball joints etc etc

My feeling is that it's being caused by the ARB being solidly mounted

At the top of the pic, you can see the rose-jointed link arms

44DHR · Post by **44DHR** » Thu May 08, 2014 12:08 pm

Candellara,

I have also just taken off my rose jointed Anti Roll bar links. When I bought my uprated ARB from Rob Beeere several years ago, he also gave me poly bushes to mount the ARB and a set of poly bushes for the drop links. I have now fitted those poly bushes to the standard ARB links.

I am removing the rose jointed drop links as I do a bit of Continental driving and these make the car too firm for normal driving on rough roads - and for the Isle of Wight roads !!

I note your drop links have the rose joints aligned the same way. Should they not be at 90 degrees to each other as one joint bolt goes through the lower suspension arm and the other top joint bolt through the ARB.

I also run poly bushed steering rack mounts - a real improvement - especially with wider wheels and tyres. I would not consider solidly mounting the steering rack on a road car.

I will put the car back on the road this coming weekend to see the difference.

regards,

Dave

Candellara · Post by **Candellara** » Thu May 08, 2014 2:02 pm

Hi Dave

Yes, this was pre-installation, so they do run at 90 degrees. The more i think about this, i can't help but think that my "clonk" could be coming from the reaction plate.

I am really unfamiliar with reaction plates and need to understand how they affix to the body. Are they bushed?

Following the process of logic, is it feasible that when the car hits a bump, that the shock is transmitted down the torsion bar (logical :-)) and then causes the reaction plate to knock against something? due to misalignment, worn bushes etc

PeterCrespin · Post by **PeterCrespin** » Fri May 09, 2014 7:05 pm

Candellara wrote:Hi Dave

Yes, this was pre-installation, so they do run at 90 degrees. The more i think about this, i can't help but think that my "clonk" could be coming from the reaction plate.

I am really unfamiliar with reaction plates and need to understand how they affix to the body. Are they bushed?

Following the process of logic, is it feasible that when the car hits a bump, that the shock is transmitted down the torsion bar (logical :-)) and then causes the reaction plate to knock against something? due to misalignment, worn bushes etc

The reaction plate is massivle strongly and totally solidly fitted to the body main rails. There shouldn't be anything loose there. What about exhaust or transmission mount and central rubber bush? Or delaminates twin rubber bobbins if your box is an early one of 5-speed? Can't see yiu car year on this iPhone

44DHR · Post by **44DHR** » Sat May 10, 2014 3:58 pm

Candellara,

I was going to reply to your question regarding how the reaction plate is affixed yesterday and as Pete says above, it is an extremely strong plate which is solidly bolted by a single bolt each side of the car.

I held off a reply, as today I am working on the car this afternoon and it is probably easier just to take a few photos while I have to car in the air and parts removed to show the arrangement in the photos below. The torsion bars at the rear ends fit into splined mounting brackets which are bolted with two bolts each side to the transverse reaction plate. I have lowered my car, hence the markings on my bars and mounting brackets.

The final photo shows the two mounting bolts holding the bracket through the reaction plate and the solid mounting to the car.

I trust this helps and I think unless any of the mounting bolts were loose, I don't think this would be the source of your clunk.

regards,

Dave

david muir · Post by **david muir** » Sun May 11, 2014 1:19 pm

Hi, Funnily(?) enough, I've been chasing this same sort of clunk from the lower passenger bukhead area for a while now! Mine manifests itself on braking. Have mentioned it on here and suseqwuently went round the reaction plate mountings.............none loose!
Still mystified and looking. Have wondered if it's a split somewhere which opens/closes under acceleration/braking but again no sign of anything amiss!
D

jag68 · Post by **jag68** » Mon May 12, 2014 5:21 am

For several years I ran a 1" front bar with poly bushings and rose jointed links. I mounted the bar to the picture frame just as the factory mounted the 3/4" stock bar. This was not strong enough, and the effect was to badly crack the portion of the picture frame which secures the top of the bracket that hold the bushing, on both sides. These cracks went right through the sheet steel and were 1" plus long. They were not readily visible. On my '68 the top of the bracket is bolted with a short 5/16 bolt that only goes through the front sheet metal part of the picture frame - that is it's not through bolted to the rear sheet metal. Doing so with a drilled aluminum block the was the same width as the distance between the front and back sheet metal resolved the problem. This was a number of years ago and I can't recall if there was clunking - but your removal of the links and the resultant lack of clunking would suggest that that's somehow the problem and not the torsion bar reaction tie plate. I haven't used a big bar for a number of years. A modification that Jaguar used in racing these cars (lowering the upper pickup points of the top control arm) is much more effective way of increasing front grip than a big bar.

Candellara · Post by **Candellara** » Mon May 12, 2014 8:04 am

Thanks all

I've checked the reaction plate and all seems ok. Engine & gearbox mounts are all new. It's more of an annoyance than anything else but i think i'll revert to a "fast road" adjustable roll bar with polybushed link arms rather than solid rose-joints.

The bonnet, rad etc will get removed at the end of the Summer and i'll investigate more fully then.

Candellara · Post by **Candellara** » Mon May 12, 2014 6:19 pm

I've had a quick look tonight at the ARB mounts to picture frame and the upper bolt only goes through the front section of the picture frame - not through the entire width of the frame. Oddly enough the picture frame has two holes so i assume the ARB mount bolt should travel through the complete width of the picture frame? Has anyone got a pic of how this is supposed to be affixed?

jag68 · Post by **jag68** » Tue May 13, 2014 6:45 am

That's the way it was done - with a stock bar it's strong enough it seems. I had no trouble until I went to the 1" bar.

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