steering on a gt3rs
Discussion
took a gt3rs out for a test drive at the weekend. clearly an awesome car, and the first thing i noticed about it was how go-karty the feel to the steering was. mine feels sloppy in comparison. does anyone know how you can 'tighten up' the steering to give it that much more directional feel?
911nutter said:
took a gt3rs out for a test drive at the weekend. clearly an awesome car, and the first thing i noticed about it was how go-karty the feel to the steering was. mine feels sloppy in comparison. does anyone know how you can 'tighten up' the steering to give it that much more directional feel?
It is basically down to set up.
You will probably find the RS was running a lot of negative camber, this makes the car turn in a lot sharper, but this has to be done in balance on the rear aswell, other wise you will get massive oversteer.
This will make onroad manners a bit more 'focused' but fun none the less.
If i remember from my laps in your GT2, it understeered quite a lot, so you should get it set up if you're gonna track it a bit.
Just ring JZ Machtech or Parr, these should do it for around £500, the difference will be amazing on track.
G.
911nutter said:
don't understand this negatove camber thing. what does it mean? will it effect wear on the tyres? ie uneven - more on the outside?
Negative camber means that the top of the wheels are nearer the middle of the car than the bit nearerest the tarmac. This is different to toe-in which means that the front of the wheels are nearer the centre of the car than the rear of the wheel. Toe out means the opposite.
For aggressive turn in you need to add negative camber. Some people (eg Colin Belton) also add a little toe out of the front wheels, but I have kept my front wheels at zero-toe so it isn't too twitchy. Typical negative camber for a track day car is around 2-3 degrees.
Negative camber wears out the inside of the tyre more than the outside as the inside of the tyre has more contact with the road unless you are cornering hard. The advantage of negative camber is that when cornering (and the car rolls a bit) the tyre is then flat against the tarmac and therefore grips better. You don't want too much negative camber though because then you have less grip for braking when travelling in a straight line (or indeed acelerating if we are talking about the rear wheels).
Like everything in car set up, it's about comprimise.
I've got just over 2" of negative on the front of my GT2, it helps the tyres work much better when pushing on, but as said here if you use a motorway there are now sections that I cannot go into the inside lane without having to fight the wheel (and I mean really fight).
As stated above there are lots of people who can help you out but every change will bring other consequences that you might not expect. Find a decent garage with someone who has developed some decent settings, get the car setup, drive it, tell them what you like and dislike and it can be tweeked to suit you, one advantage of the fully adjustable setup on the GT2!
My setup still has a small amount of understeer built in which the power can easily push past, but it just helps avoid too much sudden tail slide, which with the turbo lag I prefer to know when it's coming. It's a very similar feel to the factory setup on the GT3RS to be honest, just took a bit of fiddling to get to.
As stated above there are lots of people who can help you out but every change will bring other consequences that you might not expect. Find a decent garage with someone who has developed some decent settings, get the car setup, drive it, tell them what you like and dislike and it can be tweeked to suit you, one advantage of the fully adjustable setup on the GT2!
My setup still has a small amount of understeer built in which the power can easily push past, but it just helps avoid too much sudden tail slide, which with the turbo lag I prefer to know when it's coming. It's a very similar feel to the factory setup on the GT3RS to be honest, just took a bit of fiddling to get to.
...also need to be aware that with toe changes (in or out), you'll also change the stability under braking, i.e., when braking, weight transfers to the front, front susp compresses, front geometry will change as a result. Not experienced in setting up Porches, but certainly on Westfields/Caterhams, this weight transfer will then cause steering arm geometry to change relative to the rack (because the rack is essentially now closer to tarmac), thus steering will be affected. Too much toe will result in instability under hard braking.
GT-One did a 4-wheel susp setup for me the other week for "Fast Road" with +0deg10mins front toe, -0deg18mins front camber, +0deg9mins rear toe and -1deg19min rear camber. (All static) This is just a tad less aggressive than what I bought car with (which I think had little more front camber) and feels v good on all road surfaces. I don't track this car, so deliberately not optimised for billiard smooth surfaces...
Only cost £185. Was on a 996 C2, so not as adjustable as a GT2/GT3RS, but of course is 2WD not 4WD...
Hope this helps. Spen
>> Edited by spenny_b on Friday 3rd June 15:05
GT-One did a 4-wheel susp setup for me the other week for "Fast Road" with +0deg10mins front toe, -0deg18mins front camber, +0deg9mins rear toe and -1deg19min rear camber. (All static) This is just a tad less aggressive than what I bought car with (which I think had little more front camber) and feels v good on all road surfaces. I don't track this car, so deliberately not optimised for billiard smooth surfaces...
Only cost £185. Was on a 996 C2, so not as adjustable as a GT2/GT3RS, but of course is 2WD not 4WD...
Hope this helps. Spen
>> Edited by spenny_b on Friday 3rd June 15:05
If you increase neg. camber, then take your car to a circuit and lower the pressures for it (33 front, 37 rear hot would be about right for GT3), be sure to raise the pressures back up before you go back on the public road. You would be shocked by how quickly a slightly-underinflated tyre wears on the inside edge, especially with a lot of neg. camber.
Gainsboro said:
This is just the info i am looking for.
Can someone please suggest ideal settings for road use to reduce wandering under braking/ tramline whilst staying within the recommended settings
GT3 2005
Thanks
If you reduce this, you'll affect turn in and steering feel. Seems an odd choice for a GT3 as if you want that stability surely the trackday special GT3 isn't the right 911?
beaver said:For the circuit, I think you might wish to use 32/36 hot.
32/37 is standard pressure on GT3, 32 hot all round is
supposedly the best combination on track.
The indicated pressures for the street look low (presumably you are referring to cold pressures for street). You might wish to use 36/40 cold.
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