Help pls! Getting the car set up for B-road driving

[greedygekko]

I'm massively enjoying my new Roadsport 150, but it feels more set for the track than the road. I've driven a couple of CC cars, and mine feels a lot more twitchy.

A friend and I checked the suspension, for example, and the front was wound right up to it's hardest setting so the front end was *very* jittery on bumpy B-roads. We've also noticed some uneven tyre wear on the inside of the fronts, and the rear suspension is pretty tight too.

The search function is down at the moment, so does anyone have any recommendations for anywhere in the south that's good for getting cars set up well for the road and can have a good look over the tyre balance, toe-in angles and suspension set-up?

Thanks! (PS sorry for including my ugly mug in the pic...)

[Gingerbread Man]

I've just emailed James with a few places off the top of my head. I hope it all gets sorted and you get out for a run soon.

[greedygekko]

Gingerbread Man said:

I've just emailed James with a few places off the top of my head. I hope it all gets sorted and you get out for a run soon.

Great, thanks!

[Incorrigible]

Usual plug:

We're in west Sussex, if that's any help www.classiccarworkshop.co.uk

[BDA]

Suspension set up is a a complete work of art and a minefield. As you have already identified it depends what you want out of your car, but also your own preferences and driving style. it's fairly easy to get some else to set your car up but if you don't know how to tailor it to your own prefernces it will be either very expensive or a waste of time in my opinion.
It's better to start learning how to set your own car up. Find some one local to you who can help you in the right direction to learn and do a lot of reading and experimenting, that's what I did and 25 years later I'm still learning. Sorry this is not really that helpful but I believe ultimately the best way forward.
As a start though toe and rack height (bump steer) will particularly effect front end stability on the road, toe in will give more stability. Rear end wise I assume your car is de dion, do you have a rear anti roll bar, this tends to cause twitchyness on the road.
Uneven wear could be caused by incorrect toe or possibly incorrect camber, it's hard to tell without seeing the wear pattern.

If I can help any more, just shout.

Cheers
Chris

[mickrick]

What he said above. Read, read, read, play. But write everything down.

[stowc]

Like you, my car was very twitchy and hard to drive on bumpy B roads. At first I thought that was just the way the R300 rode but I was also constantly grounding out on speed humps and there were some nearby that I couldn't get over.

I took it to DPR motorsport in Abinger Hammer and discussed what I wanted and they reset the ride height (it was running on the bump stops), did the corner weights and reduced front camber (to somewhere between its old setting and Caterhams recomendation).

Very pleased with it now.

[greedygekko]

Thanks for all the help guys.

stowc said:

Like you, my car was very twitchy and hard to drive on bumpy B roads. At first I thought that was just the way the R300 rode but I was also constantly grounding out on speed humps and there were some nearby that I couldn't get over.

I took it to DPR motorsport in Abinger Hammer and discussed what I wanted and they reset the ride height (it was running on the bump stops), did the corner weights and reduced front camber (to somewhere between its old setting and Caterhams recomendation).

Very pleased with it now.

stowc - did DPR have a pretty good handle on the "standard" set-up as a reference point?

[Gingerbread Man]

Incorrigible said:

Usual plug:

We're in west Sussex, if that's any help www.classiccarworkshop.co.uk

You were a recommendation in my email.

[Gingerbread Man]

BDA said:

....do you have a rear anti roll bar, this tends to cause twitchyness on the road.

I run mine daily on the road. Does the rear anti roll make a big difference?

[mrloudly]

My monies on camber or you need a bit more toe in. Doubt it'll be corner weights you'd feel that more under braking (locking).
Just moved from an R400 to X-Bow, coming bit of a setup guru... Slow damping, fast damping, rebound damping, ride height, toe (front and back), camber....
arrrgggghhh. Have also been amazed how critical hot tyre pressures are as well.
To be fair the X-Bow is a bit skittish on bumpy roads, get it on a track or smooth bits and with 360BHP :-) it's "Bye" ;-)
Hope you get it sorted

Regards

Andy

p.s. Mark at Backdraft Motorsport is very good

[davidball]

Twitchy! Welcome to the world of the live axle, a real thrill on cobbled roads.

[thequietone]

Pleased to hear you're enjoying the Caterham!! Is it your first? Unless the dampers have been changed they are not adjustable for either compression or rebound. When you say 'wound up tight', do you mean the spring adjusters were quite high up the damper body?
If you bought it from CC, speak to the guys there (Kevin I think) or drop it back round. Had an SV of mine set up by them some time ago - made a huge difference.

Just my 2p

[stowc]

greedygekko said:

stowc - did DPR have a pretty good handle on the "standard" set-up as a reference point?

Yes they did seem to. They were quoting standard figures from memory and pointing out how far mine was away from them. It sounded like my car had been purely set up for track and we went for settings that were a bit less agressive.

[Chris71]

It's worth checking the anti-roll bars too. As most bumps will have more of an impact on one wheel they do have a bearing on ride as well as roll.

Mine is still running full-on track geometry and it follows grooves and cambers quite dramatically on the road. Can be really quite exciting on a bumpy country lane and I don't remember the road-biased cars I tested being quite so frenetic!

Edited by Chris71 on Thursday 9th September 11:25

[Steve-B]

We had our SV done with us in the car when we first got it in 2002. Had a checkup with just me before sprinting in Australia a few years back.

The most important thing I took from it was marking/measuring track day flat flooring corner weights to normal aggre^pootling around settings.

That way I can change at N/C to me for the conditions that we'll be encountering.

[greedygekko]

thequietone said:

Pleased to hear you're enjoying the Caterham!! Is it your first? Unless the dampers have been changed they are not adjustable for either compression or rebound. When you say 'wound up tight', do you mean the spring adjusters were quite high up the damper body?
If you bought it from CC, speak to the guys there (Kevin I think) or drop it back round. Had an SV of mine set up by them some time ago - made a huge difference.

Just my 2p

Thanks - yep this is my first (and I suspect not my last...). You're spot on - spring adjusters right up the damper body.

[greedygekko]

stowc said:

greedygekko said:

stowc - did DPR have a pretty good handle on the "standard" set-up as a reference point?

Yes they did seem to. They were quoting standard figures from memory and pointing out how far mine was away from them. It sounded like my car had been purely set up for track and we went for settings that were a bit less agressive.

Excellent - sounds good, thanks.

[BDA]

Gingerbread,
To answer your question, Yes the rear anti roll bar generally causes the rear to feel a little skittish particularly on bumpy roads. If you disconnect it the rear will obviously roll more but the car will tend to be more stable in a straight line. As an example I have a live axle car and on a dumpy french D road an SLR had trouble staying with me at speeds in excess of 100mph as he was fighting to keep the car on the road/in a straight line as the back end was all over the place, disconnect the Anti roll bar and there was a significant improvement. Completely different on very smooth roads or the track though.

Cheers
Chris

[Gingerbread Man]

BDA said:

Gingerbread,
To answer your question, Yes the rear anti roll bar generally causes the rear to feel a little skittish particularly on bumpy roads. If you disconnect it the rear will obviously roll more but the car will tend to be more stable in a straight line. As an example I have a live axle car and on a dumpy french D road an SLR had trouble staying with me at speeds in excess of 100mph as he was fighting to keep the car on the road/in a straight line as the back end was all over the place, disconnect the Anti roll bar and there was a significant improvement. Completely different on very smooth roads or the track though.

Cheers
Chris

Thanks Chris. So it's one of those things that has it's positives and negatives and it's down to user preference. I'll look into removing mine and trying it with and without.

Thanks.