Toe and Camber settings

I had the rear tyres replaced today - wear was pretty uniform at 2.4mm left on the outer and 1.8 on the inner, and they tyres were on when i got it 7000 miles ago.

I had the geometry checked on a Hunter machine, and it was so way out they removed everything and checked again, and got the same results.

Basically the toe figures were pretty much exactly double what the database said was maserati spec. Front toe was 22 and 20 minutes (spec is 9 +/- 1) and rear toe was -29 and -12 (spec -9 +/-1).

As the front ones were so completely similar and double the original figures, we figured it might be too much to be a coincidence, so left them alone wondering if it was a common change to improve turn in or something (and it was nearly 5:30 by then).

I've had a search and a look on the interweb and can't see anything about this, so is it just that the car is out of true by the same amount?

Thanks

I was looking for geometry figures and find here what the toe should be. But no data on camber. And I want to take the car to track the end of the month so I would prefer a track friendly setting. I found a write up from PorscheGirl on aggressive set up but the target to get car to 911 turbo ride feeling could guide wrong.

Suggestions on ride hide but still keep the comfort when cruising and suggested tyre pressures for track please. Many thanks in advance for your support.

The set for the AC version is
Front:
Toe in 1.5 / 0.5 mm Camber -30' / +10' Incidence 4 deg 30' / 15'
Rear:
Toe in 4.0 / 0.5 mm Camber -1 deg 30' / 10'
Personally I have always had more toe in front and rear than the spec says, i think it makes the steering more positive, it tends to be a bit drifty on the recommended settings. Then thats me!

Toe in will make it more stable. Toe out would (as I simplistically understand it) give you a faster turn for track use. The GTs suffer from inside edge tyre wear due to (we think) the factory settings. Several of us have had this changed and mine was most recently set to zero toe. Made a huge difference, but then it was all over the place when it went in!

Needs doing again though

C

CatmanV2 said:

Toe in will make it more stable. Toe out would (as I simplistically understand it) give you a faster turn for track use.

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Exactly. With the front wheels pointing towards each other (toe in) stability at high speed is increased. If someone wants a fast road set up I will set zero toe as this will improve the turn in. Track drivers/racers will run with a small amount of toe out - although the turn in is amazing, I find the car is all over the place on anything other than a super smooth surface (ie: cannot be driven on UK roads!).

The more camber you put on the more grip you'll get in the corners as the outside tyres roll into the road. However too much and you'll compromise braking performance.

If it is any help here are the settings for the GS, 4200 will have some differences due to ride height.


it's just about readable.

Cheers Greg

Thanks to all. So the chart is same for 4200 and Gransport?

In this case, standart is -0,4mm and suggestion is 0,0 for front toe? Anything else?

Track is Istanbul park, designed for F1 racing. So need to feel safe at high speed curves.

CatmanV2 said:

. .......mine was most recently set to zero toe. Made a huge difference, but then it was all over the place when it went in!

C

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Made a huge difference to what? What went in to cause being all over the place? And what is meant by being all over the place? I'm confused because if handling and precision of fast curves is improving with 0 toe, what is the compromise?

Setting the front to zero i would have thought give the car a tendancy to wander around when driving in a straight line. Lots of small corrections needed to keep it straight.

Tufan said:

Made a huge difference to what? What went in to cause being all over the place? And what is meant by being all over the place? I'm confused because if handling and precision of fast curves is improving with 0 toe, what is the compromise?

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The handling was much much better. The settings were all over the place when the car went in to get the geometry sorted. Wheels pointing in different directions, everything was a mess. So it's not surprising it handled better afterwards. Or at least more predictably

C

spkennyuk said:

Setting the front to zero i would have thought give the car a tendancy to wander around when driving in a straight line. Lots of small corrections needed to keep it straight.

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Not that I noticed

C

Tufan said:

I was looking for geometry figures and find here what the toe should be. But no data on camber. And I want to take the car to track the end of the month so I would prefer a track friendly setting. I found a write up from PorscheGirl on aggressive set up but the target to get car to 911 turbo ride feeling could guide wrong.

Suggestions on ride hide but still keep the comfort when cruising and suggested tyre pressures for track please. Many thanks in advance for your support.

Click to expand...

It all depends on what kind of track you're driving.
As a rule the camber should be set to get a good flat tyre print at mid corner, you don't want one edge taking all of the weight and rolling the tyre on the rim as that's when it can stress and break away like a quick snap. The flatter the print in a corner the more likely it will drift and be able to be saved rather than pushing and snapping away.

As for pressures, this will need to be factored on conditions on the day and how fast you drive. Don't be afraid to experiment but I'd advise getting a trusted pressure gauge to help you, small incremental changes are best. As a rule the hotter and faster you go the less pressure you'll need but you will have to make sure you get heat into them gradually before pushing as you could roll the tyre on the rim or buckle the wheel if you hit some curbing too hard.
I'd advise a tyre with a hard side wall and carcass for track use as the car has some weight and standard suspension is on the soft side.


For anyone taking the car on track for the first time try and get used to how the weight moves around first. You want to make any transitions as smooth as possible first and then increase the speed.
And remember you have the most traction and grip whilst accelerating and braking. Keep these actions as linear as possible and don't open the throttle until you're sure you won't need to come off it again.
Hope this helps a little. Enjoy the day.

R

Thanks for the tips. I have been on circuits with quite different cars BMW single seater (Hungaring), Caterham short experience, old timer Fiat 124 etc. Also did time trials with my heavy but modified Saab 9-5 Aero estate beating 2 Porsches. Last one thanks to 2nd hand slicks and my well experience with the track.

May I ask what ride heights are suggested for fronts and rears? No chance for corner weighting nowadays around here.

Tufan said:

Thanks for the tips. I have been on circuits with quite different cars BMW single seater (Hungaring), Caterham short experience, old timer Fiat 124 etc. Also did time trials with my heavy but modified Saab 9-5 Aero estate beating 2 Porsches. Last one thanks to 2nd hand slicks and my well experience with the track.

May I ask what ride heights are suggested for fronts and rears? No chance for corner weighting nowadays around here.

Click to expand...

Tufan,
I see you have track experience. I was unsure so just put some general comments just in case.

I seem to remember past posts say they had reduced ride height by 10mm and got a good result but can't find the thread, I think it was with regard to upgrading springs too. Perhaps someone else can elaborate.
There is a thread relating to the 4200/GS with some useful info called "Toe settings" (sorry, unable to attach a link - not got to grips with new phone yet).
Hope you find the info you're after to make the most of your upcoming track day.

R

http://www.sportsmaserati.co.uk/showthread.php/8798-Toe-settings?p=188663

Here is the link, thanks R. I need to figure out the measurements now. I thought measurement was from a different location.