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p.mole1
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Front end grip

I seem to have a problem with grip at the front, having returned from Croft the front tyres are in a right state. The front seems really vague around high speed corners. The Jim clark s bend I think they are at the top of Croft circuit. 

I have 13 wheels 205/60 13 and 185/55 13 tyres Toyo 888 inflated to 15 psi cold the car is a narrow track with a rear anti roll bar set to the mid position. A 15 mm rake with the tracking set to parallel 1.25 degrees negative camber and the castor is set to standard road setting. I have also corrected the bump steer. I am using quite soft springs but have adjustable damping as it is primarily a road car  

I have tons of rear end grip and the rear tyres seem to have even wear and do not look like they have melted.

I never mess with tyre pressures, should I ? Is it worth trying to get hold of a wide track suspension.  

Because I use the car on the road I do not want to go to extremes and spoil the cars stability.

 

p.mole1
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Front tyre

Amos91
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Not sure what we are looking at as that tyre looks absolutely fine.  That is all rubber pick up from the track which will go with road miles or you can remove it from a heatgun & scraper.


What were your hot pressures?  Could try a little more front camber if you're struggling for grip.

 

Olly Amos - 2008 Caterham Superlight Sigma 150

p.mole1
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Hi thanks,

To be honest I just set my pressure cold and just leave it alone. I have never checked them hot.

I have never really had much confidence in the handling of the car, I can get around a circuit at a reasonable speed but reach a limit were I do want to push further as I can't really feel what the car is doing and it doesn't inspire confidence.

That said I have never driven any other Caterhams so I don't know if mine is good or bad. I was thinking of adding more castor to increase the camber whilst turning,increase the static camber a bit more and add a very small amount off toe out.

From experience with front wheel drive cars if there is any toe in it makes the steering terrible, but I have checked mine multiple times and it is almost parallel, just a few seconds of toe out. 

I don't want to ruin the cars stability, when I bought it, it had lethal amounts of bump steer so driving it on the road was a white knuckle experience. It took me some time to correct this, I am assuming that I haven't done some wrong by dialing this out.  

TomB
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Sounds to me like you need to invest a couple of hundred quid in a setup/ flat floor session.  If your based in the north, I can recommend Dave Gemzoe near Wakefield.  

Richard Price
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P.mole1,

What springs and dampers all round?

What ARB's front and rear?

The front seems really vague

What do you mean by that? 

As a rough guide, I's say that -1.25° camber is way too little for track use.

If its steering weight you'd like to increase, that increasing castor may help (more washers behind the lower wishbones). 

 

 

Golf Juliet Tango
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I have never really had much confidence in the handling of the car, 

Get a professional to set it up to your liking.

Stephen

Democratic dissent is not disloyalty, it is a positive civic duty

Geoff Brown
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15 psi cold is a little low for a Seven?

The recommended minimum cold running pressure is usually 18 psi. In my experience this can be adjusted either way by maybe 1-2 psi to get the car 'feeling' right. 17 psi is my target cold pressure.

Hot pressure is important but not having experience of R888R cannot really comment. Best guestimate is 22-24 PSI. This is important if on track all day & experimentation is the only way to get the car 'feeling' correct.

You could increase camber a touch, maybe to 1 degree 30. A small amount of toe out, 5 to 10 minutes will aid turn in but the penalty is feathering of the inside edge.

I have run 10 minutes toe out for some years but have decided to reduce it to 5 minutes or if possible less, but not parallel, as I still want good turn in but a reduction in the width of the feathering. 

aerobod
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I have found with the AR-1 tyres I'm running with relatively stiff sidewalls for a 7, that track cold pressures are 15.5 PSI front (185/60-13 tyre) and 13.5 PSI rear (235/45-13 tyre). This gives the optimum tyre roll and typically around 19 to 20 PSI hot pressure (usually 17.5 PSI after a cooldown lap, slow pit track-out and the time it takes to get out the car and check the pressures).

James

p.mole1
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Hi,

Many thanks for all your help, I may have to bite the bullet and pay a professional  to set it up. I much prefer to do everything myself as I Iike to able to understand the cause and effect of adjustments so I can then do all the work myself.

I used Dave Gemzoe to set up my engine on the rolling road and he is a great guy. 

I have no idea what type of anti roll bars I have, I have Nitron dampers but I am not impressed with the fronts they have very little  travel and seem drop onto the bump stops as soon as you turn into a corner and  that is with quite a high ride height. I think the damper bodies could be too long? I am not sure if this could be an issue. the rears are absolutley fine 

Front springs are 200lbs and rears 130lbs  

 

p.mole1
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I think I need to speak to Dave Gemzoe