R400 Suspension Upgrade & Faster Steering Rack??

[Cool Hand Luke]

Hi,

I recently bought a 2003 R400, and subsequently done a couple of track days. I've got a set of magnesium wheels with slicks which really improves things.

Absolutely love it, but am a little disappointed that it has a tendency to understeer. Power oversteer is there obviously, but more turn in would be greater.

I have been advised that any suspension adjustments are largely negated by the "soft" standard suspension. I am looking at fitting uprated dampners / shocks all round and then having it professionally set-up. I am told with the new stiffer set up, almost all understeer can be dialled out.

At the same I'm going to have a faster rack fitted. Nothing to do with understeer, but again it would appear that nearly all race / serious track cats have this fitted.

I would really appreciate any advice, as to whether these changes are necessary? I'm not looking to shave tenths off my lap time, just a more fun set-up.

Thanks

[Rich S]

Hi Luke,

If mainly track work is your focus

definitely go for the race dampers , up rated springs on the adjustable platforms.
Flat floor & Corner weighted , when set up with the right amount of rake will make all difference.
with the adjustable rear anti roll bar , and the range of front bars you can set the car up to handle almost however you wish,
but depending how seriously you want to take it , having one of the specialist Caterham race teams help you out ,like McMillan Motorsport (other race teams are available !) will massively speed things up .
Probably best to give them a call , find out when they are next doing a track day with some of their R300 racers (like me ) , and ask if you can sort something out with them .

re the quick rack , personally I wouldn't want it , I would get the car set up right first , drive it loads , then think about

[subirg]

I have an R400D and went through a similar thought process to yourself. I bought my car new and it came with the standard suspension and CR500s on 13 inch wheels. Eventually this is what I did:

1. Fitted race suspension and softer front ARB (orange)
2. Changed tyres from CR500s to the new ZZRs
3. Flat floor, corner weight and full geo set up by one of the trusted race outfits (in my case Fauldsport).

Handling is very neutral now with understeer virtually banished (apart from the very highest speed corners when a quick lift can help turn the car in). The race suspension definitely helps to improve cornering speeds, and the ZZR tyres are a big step up in dry weather grip over the CR500s, but need the geo set up properly to work. I'm very happy with the way things are and I find the standard rack is still plenty fast enough for me - so haven't upgraded to a quick rack yet.

[DCL]

subirg said:

I have an R400D and went through a similar thought process to yourself. I bought my car new and it came with the standard suspension and CR500s on 13 inch wheels. Eventually this is what I did:

1. Fitted race suspension and softer front ARB (orange)
2. Changed tyres from CR500s to the new ZZRs
3. Flat floor, corner weight and full geo set up by one of the trusted race outfits (in my case Fauldsport).

Handling is very neutral now with understeer virtually banished (apart from the very highest speed corners when a quick lift can help turn the car in). The race suspension definitely helps to improve cornering speeds, and the ZZR tyres are a big step up in dry weather grip over the CR500s, but need the geo set up properly to work. I'm very happy with the way things are and I find the standard rack is still plenty fast enough for me - so haven't upgraded to a quick rack yet.

I'd agree totally with this. Get the geo right and a a set of ZZR and understeer is history.