Top link front suspension upgrade for live axle car - is it worth it?

[Ralph Morgan]

Having replaced the ageing Crossflow with a Dunnell Zetec in my 1990 live axle/long cockpit car last year, my thoughts are turning to a few chassis/safety upgrades this year. An FIA rollbar seems a good starting point, together with seat headreasts, but it's also tempting to upgrade the front suspension to the later separate top link spec. which I believe is fairly easy to do, especially as I have the later neg-camber lower wishbones. I recall considering this when I ordered the chassis, but at the time Caterham didn't reckon I would notice any difference on a live axle car so I didn't bother (especially as I was building the car on a shoestring!).

 

Is this still a valid view, or would it be worth doing? It certainly appeals from a basic engineering viewpoint, giving much better location of the top link and easing the load on those alloy anti-roll bar mounts, but I'd be interested to hear from anyone who's done the job on a similar car. Main questions are: how much does it cost/is it as easy as it seems/was it worth the trouble?

[Ralph Morgan]

Should have looked at other recent postings before I wrote this! The Trunnion thread below seems to confirm it's worth doing, but I'd also be interested to hear thoughts on ease of installation and cost.

[Mark H]

Ralph, i can only comment on some short test drives of customers cars that have come in to my workshop . I would say that it is worth it for the increased stability under braking alone. Having an early De dion with out a full top wishbone myself i was very surprised at the differance , i also thought at the time that it tended to bumpsteer less.

So i for one would say yes 😬 do it

 

 

Mark ,Anglia sevens

 

flares n, flames

 

Edited by - marc hicks on 16 Feb 2003 22:28:34

[Casbar]

The whole kit cost £218.00 a couple of years ago. Although if you have trunnions, you should replace the rod ends with the one that has the correct joint, as the kit comes with the ends for the non trunnion uprights. This has been discussed many times before, but happy to let you have the rod end part numbers, they cost about £5.00

 

I think its a good upgrade.

[Mat Norris]

Has anyone done this conversion on a short cockpit/Live axle chassis (1983/4)? Is it still the same bits that are needed or is it different? Thanks.

[philwaters]

I think Ralph means the ~£100 kit that gives you a small link that forms a top wishbone and then a new ARB which is now free from the burdon of forming part of a wishbone and can get on with being an ARB.

This is easy to fit - I did it last year - and just involves making a hole each side for the new link to pass through. The link itself is then bolted to the back of the ARB mounting points (with longer bolts and you get a position template) and then fits tight into the old ARB location. The new ARB then sits in postion over the top, as it were. I was dissapointed that you still can't get anything other than a 1/2" ARB though ☹️

 

As to the difference. Well, I changed so much last year that I couldn't be 100% sure, but the car has far better turn-in with what feels like better feedback. For the price, I think it is worth doing. I couldn't justify the £500 odd that it costs to go full double wishbone and loose the trunnions - which have never given me a problem.

One tip. Buy a hole punch/cutter from somewhere like RS. They are eay to use and make a very neat hole, and seeing as the hole needs to be 25mm dia - it is better than drilling.

 

Phil Waters

You mean you can drive these?

I thought it was just there to polish 😬

[Casbar]

 

 

I didn't know you could still buy just the top link. Going the de-dion double wishbone route, allows any size roll bar you want and adj top wishbones allow you to play with camber.