Old style front suspension, can it be converted, upgraded, is there any gain and is it worth it?

[Phil]

I have a 1990 car with the old style front suspension, cross style top link.

Can it be upgraded, what is involved?

Any pictures please.

 

Thanks Phil

[Chris Cardwell]

Phil

 

My 1991 car front suspension was converted when the clam wings were removed by James Whiting, it transformed the handling.

[George C]

The biggest difference comes from having good dampers (something like AVO or Nitron), correct springs and good tyres. If you get this right with the car carefully set up and all in perfect order then you have 98% or more of the performance of the later set up.

 

Wide track and the later top links look nice and will help a very small amount but is not at all essential. The original set up still works suprisingly well but must be correctly set up.

[bstark]

Hi Phil,

 

I have the old-style suspension and have been pretty successful in local sprints with it. According to 7 Indulgence the biggest difference is that the old-style suspension is very heavy on the bushes (makes sense) so I just make sure these are in A1 condition. Also have GAZ shocks all round specifically specced for my car's setup.

 

It can be converted to the later style fairly easily apparently.

 

Haven't felt the need to change as the handling is spot-on.

[Crudders]

Hi Phil, I also have a 1990 vintage old school live axle. Before I made the change to the later front suspension design during a major rebuild (which involved having the threaded stubs to the front of the chassis cut off and bushes being brazed in to receive the new bolt fixings) I had some very nifty anti-roll bar clamps designed by Gary May. There is a surprising amount of lateral movement in the old Chapman ARB design normally, which you can see where the powder coat is rubbed away. The clamps put a stop to that and keep camber, castor etc. under control during braking and cornering. I don't know of anyone still offering that solution but if you're handy you could make your own from some billet ali. Otherwise, you'll need slight chassis mods, some bolt-on bracketry and the later wishbones. My 'bones came from a much later De Dion 7 converted to widetrack, which also required a change of uprights to lose the trunnions.

 

HTH,

 

Cruds

 

Edited by - Crudders on 8 Jul 2011 20:32:35

[Crudders]

Oops 😳

 

Edited by - Crudders on 8 Jul 2011 20:30:25

[Phil]

Thanks

 

set for sale on piston heads but what would I do about the lower trunion thing?

 

here

[Crudders]

Hi Phil, your shopping list would be something like:

 

S/H wishbone set from an upgrader;

S/H ARB and mounts, ditto;

Pair trunnionless uprights from Canley Classics @ £140ish

Pair wishbone pivot brackets from CC @ £30ish (these bolt to the back of the ARB mounts and need small holes cutting in the sideskins)

Also, depending on whether they are included with your S/H bones and what condition they're in:

Pair of upper wishbone rod ends @ £40ish;

Pair of lower wishbone spherical bearings @ £60ish.

 

As you can see, it all adds up. It makes a lot more sense financially if you have to replace certain parts anyway due to running out of talent on a track day ... and your mates with S/H parts take pity on you

 

HTH,

 

Cruds

[Revin Kevin]

Phil,

You don't need to change the lower wishbones or uprights to run the later narrow track wishbone and anti roll bar (save loads of money). The narrow track de dion top wishbone and anti roll bar brackets will fit with a half link chassis bracket. the only chassis mod is to cut a small hole in the side skin for the top front wishbone mount.

I've got a parts list somewhere if you want it.

 

Cheers

Chris

 

Edited by - Revin Kevin on 11 Jul 2011 19:44:15

[Phil]

Thanks for the help, found the brackets I need on the Caterham site, about £15 a side.

If I buy these brackets is it posible to go to wide track at a later date by swopping top and lower arms, arb and uprights?

 

[Revin Kevin]

Phil,

Yes I think so although I haven't actually done it and you will have to do the lower front mount mod to the chassis.

Just a note, if you use the trunnion type uprights the standard rod ends in the de dion wishbones has the wrong taper. You need to replace them with QR1118S, about £6 each last time I bought one.

 

Cheers

Chris

 

Edited by - Revin Kevin on 13 Jul 2011 19:03:07