Rear shocks and anti roll bar

[Tronch]

Hi

I´m thinking to replace the rear absorbers with a new telescopic kit and the rear anti roll bar kit.
What´s your opinion should I make both changes or only the anti roll, as the arm absorvers are only a few miles old?

If I change the rear to telescopic, should I change fronts too?

Thanks

 

[Dave Russell]

Telescopic shocks & ARB's both require very sturdy, well reinforced mounting points on the light sheetmetal chassis which was not designed for this. It can be done with the right hardware & a lot of work.

It's doubtful if there will be much benefit from the shock change unless you are doing serious competition & cornering at the limits on rough surfaces. To do this, you would also need wider tires & wheels.

Adding a rear ARB will induce serious oversteer into the handling. Greatly increasing the diameter/stiffness of the front bar would help to re-balance the handling, but still be prepared for the back end to pass the front when traction gets to the limit. If you are competing in auto-cross type events, this oversteer can be used to advantage by skilled drivers.

Heavier ARB's will require the same type reinforcement to the mounting points & linkage as the tube shocks require.

The overall setup should really be a correct combination of front & rear shocks, ARB rates, spring rates, tires & wheels. The ride will become very harsh & stresses on the entire chassis will be increased.

If you are serious about the project, DWR,UK has very good parts to accomplish it.
https://www.bighealey.co.uk/
D

 

[steveg]

Victoria British sells a front ARB they refer to as 3/4" but it's really 7/8". It's quite a bit less expensive than the others. The bolts they supply as links are too short but you can fix that with a trip to the hardware store.

Denis Welch says upping the front bar is the best handling improvement for the money of any suspension mod.

Mike Salter has tried many rear bars on his race cars and has told me none of them make an actual improvement in the handling, especially considering all the trouble they are to install.

FWIW my .02

 

[Dave Russell]

Steve,
I agree. My BN2 originally had a 1/2" front bar. I increased it to the LeMans 5/8" front bar. Then ended up with a 3/4" front bar.

The BN2 is a little less front end heavy & so can get by with a lighter bar. Handling is fairly neutral with 28 psi front & 32 psi rear tire pressures.

I think on the six cylinder cars, a 7/8" or 1" front bar would be about right. Front/rear tire pressures adjusted to individual drivers preferences.

All bars need sturdy links & can benefit from poly bushings. As a point of interest, the bar torsional stiffness varies with the fourth power of the diameter.
D

 

[Tronch]

Thanks

I will test rear ARB first as my front is 7/8.
I´ll keep the absorbers, because they are uprated and brand news
I will report on the experience.