Those fitting rear anti roll bars - make sure you don't over tighten the bush nuts

[shiyan]

In short, if you overtighten the nuts of the bracket holding down the bushes of the anti roll bar, it becomes really difficult for the anti roll bar to move, and it won't work properly.

I received the bar around 3 months ago and I couldn't be bothered with crawling under my car to install it myself, so I let a garage install them for me. Result was a car which felt very strange to drive.

At Zandvoort it was still driveable but at the Nurburgring 2 days later I managed to spin out under braking for Aremberg, and after going over a corner/crest after Foxhole. Things that I'd never done in 300 previous laps.

Luckily I somehow avoided hitting the barriers in both spins.

I planned another trip to the Ring this weekend, so this past Friday I decided to take a look at the anti roll bar myself. To be honest I was a little scared of going back to the Ring after the last trip.

What I found was that the bracket squeezed the bush so hard that even when you disconnected the bar from the wheels, you couldn't really move the bar. They had in essence turned into huge springs, which explained the strange way the car felt.

After loosening the bolts just a little the bar moved around much easier. That plus using the softest setting for the bar (hole at the end of the anti roll bar), combined with my long used setting of the KW V2, resulted in a pretty neutral and natural feeling car.

Did 22 laps this weekend and the car's been the best it's ever felt. I didn't time but despite Pzeor Neros rather than Pilot Sport Cups I think I was still doing 8:45ish (bridge to gantry). Understeer during steady state cornering is a lot less than before, and the car is still stable enough under braking. I might even change the bar to one hole harder.

 

[montana]

Re: Those fitting rear anti roll bars - make sure you don't over tighten the bush nut

good bit of information here, sticky?

 

[Luke.]

Re: Those fitting rear anti roll bars - make sure you don't over tighten the bush nut

how tight is too tight?

 

[Skeeter]

Re: Those fitting rear anti roll bars - make sure you don't over tighten the bush nut

Are these the bolts where the bar is attached to the rear beam (with the big U brackets) or the bushes on the droplink? The ones on the rear beam should have a thick metal plate that stops you squashing the bushes, and the instructions tell you about not overtightening he droplink ones.

 

[shiyan]

Re: Those fitting rear anti roll bars - make sure you don't over tighten the bush nut

how tight is too tight?

When you can't easily move the anti roll bar up and down with the droplinks disconnected

Are these the bolts where the bar is attached to the rear beam (with the big U brackets) or the bushes on the droplink? The ones on the rear beam should have a thick metal plate that stops you squashing the bushes, and the instructions tell you about not overtightening he droplink ones.

Yep the bolts where the bushes are held in the metal brackets. If you overtighten the bolts the brackets can squash the bushes so much that the anti roll bar does not move properly, despite the grease.

I know the instructions warn you of overtightening, but if you just give the whole thing to a garage to install, they might not pay much attention to the instructions, as was the case with my car.

Moral of the story, do it yourself or really make sure to emphasize to whoever installs your bar not to overtighten the bracket holding down the bushes.

 

[Skeeter]

Re: Those fitting rear anti roll bars - make sure you don't over tighten the bush nut

Cool. I think your right, the garage probubly just tightened everything as much as it would go.

Now to get back to being jealous of your "over 300 previous laps" of the 'Ring

 

[Luke.]

Re: Those fitting rear anti roll bars - make sure you don't over tighten the bush nut

i have to fit my droplink bushes on the weekend so I will check and adjust them, do whiteline not provide a torque figure?

 

[Skeeter]

Re: Those fitting rear anti roll bars - make sure you don't over tighten the bush nut

i have to fit my droplink bushes on the weekend so I will check and adjust them, do whiteline not provide a torque figure?

It would barely register a torque figure. The instructions just say to tighten the drop link bolt until the bushes stop rotating as you tighten, i.e. they are held in place securely, but not 'squashed'.

 

[aucky]

Re: Those fitting rear anti roll bars - make sure you don't over tighten the bush nut

NOT like a certain Trophy owner on here!

 

[Sam]

Re: Those fitting rear anti roll bars - make sure you don't over tighten the bush nut

Useful bit of information there.

Sam!

 

[Luke.]

Re: Those fitting rear anti roll bars - make sure you don't over tighten the bush nut

is there a certain way the L brackets go and also where you position the u bolts? does this actually matter? it just says assemble. mine has made a hell of a lot of difference but just wonder if it does make a difference if you fit it differently.