Firstly, a note to 'Job' Gedders (Porsche suspension background), like a prat Job, I deleted all your advice from my pm, so can't email you back to say....

Secondly, your advice was perfect. My problem was acute wheelspin powering through bends in hill climb competition. My rear anti roll bar (Whiteline) was on max stiffness, now to Job's middle position, and i have full traction under the same extreme conditions!

Thought some of you would appreciate this info too.

911

 

So that has to be worth a second ?

 

Hi,

Good to hear. Have you tried increasing front roll resistance yet? This might allow you to run more bar at the back.

regards

Job

 

Mark: No, but I'm not so scared now.....All year I've been off my personal bests by about .5 to .7 sec. You know how frustrating that is! Must be the car, not me......

Job, i've looked for an adjustable Whiteline 'kit' with a 3 hole 'blade' adjustment, but can't find one yet. Might search for one from Cusco.
Going full AVON hill climb slicks, ie rubber straight from the tree! Will need to remove a lot of the static camber on each corner, so have added this to the Xmas list along with a 360 bhp 'target' engine to catch (maybe) those bloody EVO's.

Perhaps I should go back to the 911 with Avons?

911

 

I was shocked by the price of the Avons

Mark

 

Yep, thats why I've been running Kumho V70A's at £100 a corner.
BMTR quoted £170 each plus fitting/balance = £200 a corner!

I've just got to find something more from this car or it IS back to the 911 (and a different championship)

911

 

911

Observation on move from full stiffness to medium on Whiteline rear bar also holds true for a road car, based on http://www.millbrook.co.uk/, http://www.mira.co.uk/ ( water to order tracks excellent ), and extensive testing on French "D" roads ... front to back torque bias is the basic problem for my MY98 UK, which still has marked power on understeer, I cannot get on the throttle as quickly as I would like, which would be problem for competition driving, although on the road it is a benign trait

 

Or a sponsor?

I had real problems getting the front slicks hot at the last sprint meeting, it just kept understeering till the second lap. I need a cheap track day to play with the setting some more.

Would more toe in get them hotter quicker?

Mark

 

No.
I overcame my acute understeer by adding huge caster along with 2.5 deg neg camber.
I basically copied the Whiteline extreme hill climb car spec/settings and as if by magic, all was well.

Graham.

 

As well as increased castor and camber to combat understeer, I would check the temperature spread on your tyres. If the front is washing out rather then 'roll understeer', I would expect a damping deficiency. You might want to try more rebound damping at the front.

If the car understeers mainly under power, you might want to increase inside rear wheel slip by increasing rear anti roll bar rate.

regards,

Job

 

Allegedly hoosier tyres are the best for hillclimbs & sprints, they do one that's 'sticky' straight out the box and needs little warming.