Setup for 924 racing in oz

Toe in - toe out - what's it all about - and more!
daniel
Posts: 2
Joined: Mon Apr 01, 2013 10:57 pm

Setup for 924 racing in oz

Postby daniel » Fri Oct 04, 2013 12:04 pm

Hi all,
I race a porsche 924 2.0l in australia in historic racing. I have been racing the car for a few years now and have hit a bit of a wall in terms of development. Power output is around 130rwhp, which is adequate for the class and i have had the gearbox rebuilt with close ratios. The problem is the handling. First let me list what the car has suspension wise:
Shocks are bilsteins all around
Front springs are 350lb rear torsions bars are 28mm
Sway bars are standard 968
Front suspension has nylon bushes installed, rear has only rubber bushes.
Presently the car is very good (compared to other cars in my class) around sweeping fast corners but has abysmal oversteer around tight corners. Around very tight corners i need to apply large amounts of steering lock just to get the car around the corner. I have had the car professionally wheel aligned about 18months ago but i noticed at the last race meeting that the rear suspension was visibly out. Camber Was different and one side was higher than the other. I have resigned that before i race the car next i must have the wheel alignment re done, but i am hoping that some of you can make some recommendations as to the settings i should request. Also any comments on my setup are greatly appreciated. I have devised the setup i have based on info gleaned off the net.

Thankyou

A.Kirkham
Posts: 549
Joined: Tue Apr 27, 2010 11:31 am

Re: Setup for 924 racing in oz

Postby A.Kirkham » Fri Oct 04, 2013 4:34 pm

Hi Daniel.
Your front springs sound soft at 350 lb, I would say 450 lb min. Camber angles and tracking very important. About 4 to 5 degrees neg camber front, 2.5 to 3.5 degrees rear (depends how grippy your tyres are - we use Toyo 888 as our championship control tyre, a less sticky tyre and you lessen the camber a bit accordingly). Tracking should be set 0.5 to 1.0 toe in on all 4 wheels. Maximum castor angle on the front wishbones the rear mount on the lower suspension arms adjusted fully. As for ride height our championship has minimum 76mm sill clearance permitted and all cars are very close to this. We run Leda or Gaz shocks, don't know which Bilsteins you have or how firm? Basically the firmer the better up to a point. Same for the anti-roll bars, the thickest you can get hold of. A properly set up 924 should have slight inherant understeer esp in the slower turns, and pretty much on rails through the faster stuff with an even front/rear yaw effect on the limit. Hope you get it sorted, a good handling 924 is a joy :D .
Best regards, Alastair.

User avatar
sharpe64
Posts: 258
Joined: Fri Aug 03, 2012 8:56 am
Location: Northamptonshire
Contact:

Re: Setup for 924 racing in oz

Postby sharpe64 » Sat Oct 05, 2013 8:46 pm

We should rename Alastair, the "International 924 Engineer"........

Thats Poland and now Oz? Where next.....
One of the Sharpe Brothers....Misunderstood.....
Its been a great year for me, proven what i needed to, won the races that mattered, moving back to what i know..........

tonytyres
Posts: 207
Joined: Mon May 23, 2011 3:09 pm

Re: Setup for 924 racing in oz

Postby tonytyres » Sun Oct 06, 2013 12:03 pm

At least Alistair knows what he is TALKING ABOUT :D

User avatar
sharpe64
Posts: 258
Joined: Fri Aug 03, 2012 8:56 am
Location: Northamptonshire
Contact:

Re: Setup for 924 racing in oz

Postby sharpe64 » Sun Oct 06, 2013 4:02 pm

Very true Tony...
He has helped me out on many occasions...

Now I am not racing, I can gladly say what my setup was...

Same as my mg maestro was.

22psi front, 24psi rear in normal condition for ever track.

Ledas, every track , 10 front, 17 rear, every track. If wet, knock everything down to zero...

Probably completely different to everyone else, but It worked...

Will be the same setup when I get in a Boxster as well...
One of the Sharpe Brothers....Misunderstood.....
Its been a great year for me, proven what i needed to, won the races that mattered, moving back to what i know..........

A.Kirkham
Posts: 549
Joined: Tue Apr 27, 2010 11:31 am

Re: Setup for 924 racing in oz

Postby A.Kirkham » Mon Oct 07, 2013 10:29 am

Yes I forgot to mention tyre pressures, Hen's 22 psi front and 24 rear is pretty spot-on. Also it's important to corner weight the car if you haven't done it - can make a surprising improvement. We used to try altering things with our set-up before we arrived at what we have now - trial and error and mistakes along the way but mostly it's just common sense. You can always tinker around a bit and try different things for different circuits but to be honest we don't change it at all now.

daniel
Posts: 2
Joined: Mon Apr 01, 2013 10:57 pm

Re: Setup for 924 racing in oz

Postby daniel » Wed Oct 09, 2013 7:56 am

Hi again, some more detailed info:
Front sway bar is 24mm hollow
Rear sway bar is 18mm solid.
The tyres i use are yokohama a050.
Regarding shocks, they are direct replacements for the 924. I am not allowed to modify the suspension in any way. Do you guys use coil overs or inserts in the orignal strut housing? If so how do you adjust corner weights?

Thanks again


Return to “Racing Tips And Tricks”

Who is online

Users browsing this forum: No registered users and 1 guest