Rear anti-roll bar - any good?

[Freebird]

Hi

I have had one of these hanging up in my garage for a couple of years waiting in a long line of jobs to do. It's NOS too.

Has anyone got any expereience wiith them on a Mk2 Rotorflex car?

Cheers

Glen.

[JohnD]

After much calculation, I made one for Silverback, by race Estate Vitesse.

It made an enormous difference, of course, until one day, I had to take it off, for reasons that I needn't go into, between qualifying and race.
As far as I could tell, there was then NO difference!

But Sb had a very stiff rear spring, on swing spring suspension,  to minimise camber change.
A less stiff spring might reveal some useful effect, but I doubt it.
John

[Nick Jones]

Probably only in conjunction with a stiffer front ARB to try to counteract the rampant understeer that will have created.......

Nick

[Steve P]

I bought a rear ARB kit from TriumphTune in 1986,still in the garage...
Steve

[GT64fun]

Hi Glen

Back in 80s when my Mk 2 GT6 was daily transport and I was a visitor to 'good ol pile em high srap yards', I fashioend a rear ARB from robbed parts, a bit of gas welding to shorten it and a pair of Triiumph drop links, fixed into some neat little plates which picked up on bottom of the v/link & wishbone. The bar was fixed up to the underside of the boot floor with bits I robbed with the bar.
I have always felt that rear of a GT6 is a bit too soft and I often seemed to find myself on the bump stops in decent corners or if bump presented itself mid corner, but this may be because the Mk2 spring is quite soft (185lb/in compared to 305 ish for the swing spring Mk1). Vitesse rates are obviously different but the basic geometry is presumably the same. In conjunction with the bigger front bar from a Mk3 GT6 (or possibly late Spitfire) I convinced myself it was a beneficial mod, but post rebuild have yet to refit it. I had a period with Spax adjustable dampers but I think they were quite wrong for the car and I now have Konis which are a great improvement generally.
I do still think the Mk2 spring is a bit too soft however and a recent new replacement has not really improved matters, albeit I am having 'discussions' with the manufacturer as to how we might improve matters ahead of the RBBR as I definately don't want to be bumping around Britain.
There has been discussion on the forum on this subject in the past with explanations about roll centre etc. and it might be worth you doing a bit of a search.
Hope this helps.
Regards

Ian

[GT6 M]

If ye fit the rear bar, then the suspension travel also reduces, by about 1 1/4-1/2 inches,
no sound much, but on a bumpy road, its alott, as at speed, yer arshe end is air bourne alott,
Butt, on a smooth road, wid a thicker bar upront, or 600lb springs, its quite good

I took mine off, because I was air bourne alott, and new suspension set up actually gives a little moer droop, Droop is also limited to stop it touching chassis by the shockers stroke.

BUTT, noo im running v v stikee tyres, may bung it back on to stop excess body roll
NOTE, fitting this alone, wid out other alterations to tyres press camber, toe, will reduce grip to the rear end.
So pay attention to front end too, like another bar under the first one, or a later Swinger ,n

It can be tuned to whats best set up, by just hoo stiff ye mek the attaching rubbers, tighten right up, then there little movement before it acts
leave them loose, then it cam roll alot moer befoer it acts, follow.!!

Note, it also has alott of bearing on hoo far oot wards the outer ends re attached,
As same bar dia,  but links made longer, but fitted at diff ends of whishbone will have diff effects.
the olde SAH  type, used a clamp end that fitted owa the bar, one side would be closer to chassis, turn it aroond, and the link went to VL end, diff of aboot 4 inch if memory  recalls.

What is it, a 5/8th,or 11/16th one, and what type.

Some of the bars were made for Heralds /vits that fitted onto the rear boot outriggers, but also sold for Spittys , which then had to be fitted to bigg washers int boot well, butt soon deformed the floor,!!!!
I think thee,s types were made for US,or export models though.

Too allow a little extra droop, I elongated the hole in the wish bone to a slot
it gave about 1/2 inch extra droop thats all
Butt, the nylon washers used to wear oot fast

And try and put it into middle of wishbone, not attached to the front part, this so it deflect evenly  thru the wish bone and VL.
this only pic I got of a WB with a slot init, no pics of it ont car, as did nae ev a camera then

Qestionee for ye, Will it be noticeable just using  skinneee non stikeee tyres,!!!
as to get body roll, the tyres have to grip, are they gripping so as to mek body roll.

Other optionee is to bung another leaf onto OE spring, IE, clamp a longer leaf onto say the 4 th leaf, and a rubber block on the end, so it will only come into play as the leaves are compressed onto it,  
Been thinking this one oot for a while noo, as this will limit roll, but also still give full suspension droop,
An inch or moer is alott ,if ye only got a wee one to start with, 😉
maybe of some help Glenn



M

[RobPearce]

Quoted from GT64fun

I have always felt that rear of a GT6 is a bit too soft

Huh? Too soft? You've never driven mine, obviously!

[warphi1970]

just sticking an ARB on without considering all spring rates and dampers will effect the handling of the car, if you cant break traction on the rear and you tend to get understeer when pushing into corners you may wish to stiffen up the rear or soften the front. to stiffen the rear you can look at spring or ARB but don't forget go too far and you may defeat the standard shockers fitted and introduce other issues. Its a science that's for sure but if you have one just try it and see how it goes. you could always go see a suspension tuner someone like Dave Gallop of Track developments who will tell you what you need to do to change your cars setup after a corner weight check if you wish to take it really serious. He setup my saloon car and since then its been great.

[GT6 M]

Wheres Glen on this, fitting the bar !!!

M

[Freebird]

Quoted from GT6 M

Wheres Glen on this, fitting the bar !!!

M

Glen's back, thanks for all the relpies.....I will take some photos and measurements of the bar at the weekend. From memory, the ends attach to the wishbones via holes drilled like the one Marcus has shown. The centre of the bar is bolted to the chassis behind the diff I think.

It will be a long time before I get round to fitting it (if I do) still working on the CV joint conversion - the is should perk up soon as I've found some replacement VLs to get bored out to take the MGF wheel bearings.

Glen.