Winter upgrade choice - which would be best?

[Thurtene]

Hello all

Just wondered what the collective wisdom/opinion of people is...

In a bid to stop my car lifting its inside rear wheel on left-handed corners on track, I wondered which might prove more beneficial (and I know the ultimate answer is probably 'both').

Do I upgrade the suspension (springs and dampers) or fit an LSD?

My car has had the Caterham road-going Supersport upgrade so is now a 140 Sigma (via Academy and Roadsport) with wide track front.  It runs a Green ARB at the front (second stiffest) and the stiffest setting on the rear ARB.

I do a few trackdays a year, a couple of races and use the car on the road when the weather allows. I've not had the dampers serviced since I built the car but it's a problem I've always had but now it has more poke, it's denting the fun-factor.

After that, the question of which suspension or LSD... Budget is one or the other this year. 

Thanks everyone. 

[CharlesElliott]

Has the car been flat floored?

[Thurtene]

Yep - it's done reasonably regularly. Might need doing again but only done two trackdays and one race weekend since the last setup.

[Thurtene]

To be clear - even weight across the front. As it's de dion, most weight under me at the rear - hence the problem.

i know you can set up even(ish) weights diagonally but it still won't stop me being the ballast in right-handers but a point load in left-handers. Though now you've got me thinking about a set-up DPR did for me...

[Roger Ford]

An LSD won't stop it lifting the wheel, it will only stop it spinning when it does so - and even then only if it's the correct type. I believe torque-sensing (Torsen) LSDs stop working completely as soon as the wheel is in the air.  Don't know if they're ever fitted to Caterhams, though.

[Richard Price]

I think that it's unlikely that it's lifting a wheel enough to stop a Torsen diff working unless it's when you 're bouncing over curbs?

AP suretrac and Quaife ATB are both Torsens, and have both been fitted by Caterham at some stage.

The current Titan and the older ZF diffs are plate type.

However, you're also likely to improve traction by going softer, or removing the rear ARB.

I'd go for a Titan diff rather than suspension. The diff is likely to cost half what suspension that is worth fitting would cost .

[Thurtene]

Good shout Roger - an LSD would not stop the wheel lifting but would deal with traction better.

Also need to have a think about set-up...

[Z3MCJez]

Joel - Are you still running the original suspension (presumably with spacers)? For track you want to get the race suspension and then soften the front roll bar and probably the rear one too. You won't get wheel lift if it's diagonally flat-floored. [Return]

Then you should race with us in SigMax Grads! [Return]

If you do this, however, it won't be comfortable driving on the roads. I think it becomes simply too stiff. I suspect having done 2 years of racing you will never find a setup that works for you on track if you keep it set for road though ...

Jez

[HeMan]

LSD.  Not sure it will stop the wheel lifting but without one, when it does lift you must lose all power?  At least with an LSD if it does cock a leg you won't lose drive...

[6speedmanual]

I'd sort the suspension to try to keep the wheel on the ground. 

All well and good using an LSD to stop the lifted wheel spinning, but it means that all the corning and traction effort at the rear is going though the 1 very overworked tyre on the road.  (might as well have a Morgan 3 wheelwr, LoL)

I would disconnect rear ARB completelt to begin with and then work it back in one setting at a time.

 

Peter