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Track Geometry GT3

bryce

Well-known member
Joined
24 May 2012
Messages
315
Heading to Anglesey and having not driven the car for a while I'm wondering if I should have the geometry set. I'm currently on Porsche rod settings.

It might be a one off track day so be interested to hear if it's worth spending the money. I am a fussy driver so I'd like to think I'd feel the benefit.
 
Oulton booked so looking for geo settings. Front end in particular just doesn't go where I want it.
 
Re: Anglesey Geometry.

bryce said:
Heading to Anglesey and having not driven the car for a while I'm wondering if I should have the geometry set. I'm currently on Porsche rod settings.

It might be a one off track day so be interested to hear if it's worth spending the money. I am a fussy driver so I'd like to think I'd feel the benefit.


I can't help you with settings for your car bryce, but Anglesey is a very nice circuit indeed, quite technical in places along with some ballsy corners too. Great fun!

Good luck :thumb:
 
I'd suggest taking some advice from who ever you plan to get to do it, they should be able to talk you through the pros and cons. 3' to 3.5' front 2' to 2.5' rear, zero front toe, cant recall rear toe...is fairly commonly set. It does compromise the road manners though, std is (if its not been knocked) 1.5' all round.
 
Title edited - didn't realise I could do that, thanks.

Unfortunately there are no specialists within hundreds of miles of me so I intend of having it set at my BMW dealer. There's a lad in there that has a genuine interest but he just needs the figures.

As for Anglesey, I really didn't rate it. Apart from the fast sweeper at the rear it's just long straights in to hairpin corners.
 
bryce said:
Title edited - didn't realise I could do that, thanks.

Unfortunately there are no specialists within hundreds of miles of me so I intend of having it set at my BMW dealer. There's a lad in there that has a genuine interest but he just needs the figures.

As for Anglesey, I really didn't rate it. Apart from the fast sweeper at the rear it's just long straights in to hairpin corners.

You may not be able to get the extra camber on the front or rear without some specialist knowledge. Top mounts may need re positioning, lower arm spacers etc Its not just a threaded nut adjustments thing.
 
I would certainly recommend the setup that I have (same car) though I have a moderately aggressive amount of camber on mine (over 3 degrees on the front and over 2.5 on the rear), which is fine on the multi-compound Cup 2 but you don't get a lot of road miles out of the inner shoulders of the original Cup+ with it. A reasonable compromise for you would probably be up to 2.5 degrees camber on the front, 2 and a quarter on the back, zero front toe and stiffen the anti roll bars a notch at each end and see how that works for you. It will certainly give you a better front end, though beyond that I would say send it to Centre Gravity or one of the better track oriented independents and have them bake it specifically to your taste. As Dan said - the setup that you want may call for shims in the lower arms or reconfiguring the top mounts so if using a generic shop there may be limits to where they can get it on the day. Regardless - you ought to be looking for a quarter to half degree more front camber than rear though.

Also consider using the hero switch to turn of the TC+PSM if you are confident and the conditions are okay - on the gen 2 I find that as well as eating the brakes it also resists weight transfer a bit and that might actually be part of your problem in getting turn-in.

On the 997.2 you can actually put a fairly sharp geo on it without it becoming intolerably uncivilised on the road, but you should look to have it kept at factory ride height for speed bumps and ramps and as I said earlier - the more camber you put on it the less mileage you will get from the older Cups (not really an issue with the Cup2 though).
 
Thanks lads. Didn't realise there was more to the camber adjustment than just a hub centric washer / sliding top mounts.

I'll most likely struggle to get to any specialist so I wonder if I should just go for a quick adjustment on the toe alone, or would this in isolation hardly be worth it? Does the proper set up fairly transform it Colin?

Traction control etc is fully off.

Road manners don't particularly and it'll get trailered there.
 
Before you do anything what part of your cars handling are you trying to improve?
 
Ok read thread again, it looks like you want front end grip.

If your going to Oulton Park, Sports & Classics isn't that far away, Mike has all the kit and knows how to set these cars worth going down the day before and getting it set up properly.

What I can't see in Dans or Colins posts is that they both run 245 front tyres not sure if that is standard on gen 2,it isnt on my car gen 1 and this is a big help in front end grip. Similar to both Dan and Colin I would suggest the following set up for fast road occasional track

Front end

-2'30"camber both side
8'20" caster both sides
0'03" toe in both sides. This will give better stability at high speed if you want better turn in go straight at front or even sleight toe out.

Rear end

-2'00" camber both sides
0'15" toe in both sides

Roll bars

These are easily adjusted at the track if you have spanners and a jack so once geo is set have a play with them, but to start with go with middle hole on rear bar(gen2) and 1 in from full soft at front.

If your car is more track than road then turn up the cambers front and rear but try and keep 1/2 degree difference front to rear for balance.

Rake

1 degree to the front will help car balance when breaking
 
bryce said:
Does the proper set up fairly transform it Colin?

I do find the "Transforms The Car" phrase somewhat overused on here, but the difference is very, very tangible once you are carrying speed. Having the front end pinned down just makes it lovely to drive the back end balanced on the throttle, which is what suits me. It is also fun in day to day driving - even at normal road speeds having that amount of front bite can make even mini-roundabouts somewhat less tiresome ;-)

As Jon pointed out above - the other thing that I have is the 245 front tyre on mine instead of the 235 stock size. This is the standard front tyre from the 997.2RS (so no issue if you are into your N ratings and so on) and I favour it as I find that it slightly better helps the car resist understeer on corner exit under power. I stayed with the normal 305 rear and find the balance is just where I want it so have not tried putting the wider RS rears on too (though they certainly would fit the 12j rim if you were after more traction).

The thing is : the really special thing about the GT3 is that it can basically be set up to drive how you want it to and to get the best from your driving style. There are other ways to go about it as well. Nick W went to 4 degrees on the front of his 3.8RS (with a notch less on the roll bars IIRC) and he can hurl it into tight corners, but especially on the Cup+ it developed a more serious appetite for tyres as a consequence.

My setup is more compromised than most of the track day regulars as I use it as a regular road car too (and always have since I got my first one over a decade ago) rather than a pure track trip toy. At stock ride height for better speed bump friendliness it has been said to appear on stilts parked with Danny, Jon and the 2 Nicks (who favour taking it down to a more track optimised height). If you are trailering it then you can actually get it on a completely track focussed geo which will be massively grippier than stock, but that will make it quite a bit less satisfying as a road car.

With a GT3 you can have your cake and eat it. Extending the metaphor - if you take the ingredients to a baker who really knows their stuff they can make it how you like it, so that is why we all run off to our favourite specialists to set them up. Centre Gravity in the Midlands are my go-too, but there are many others (Fearnsport, Sports and Classic, Parr, JZM and plenty more up and down the country). Nobody that I know would use a main dealer for geo though - I wouldn't even use them to set it to stock (when I acquired mine - from of all places Reading - it was not as it should have been).
 

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