GT4 Track Set Up

[430scuderia1]

Hi, my car is factory standard and want a good starting point on the geo before my first TD, does anybody have any pointers?

cheers
Barry

[Porsche911R]

I did mine straight away, as the oem understeers like a piggy even on the road, but you are pretty much screwed setting a GT4 up in oem form because while they gave you a GT3 front end they fitted non adjustable rear toe links, so you can do NOTHiNG to it, if you want to keep the car well balanced.

You will have to buy some adjustable rear toe links, then you can adjust the rear toe, because once you add camber it knocks out the toe out and with fixed units on the oem car, you are stuck ! ! lol bit of a joke really esp as they fit adjustable lower control arms at the rear ? I don't think Porsche want you to mess with it, other wise they would have fitted the final part to allow adjustment !

On the plus side the rear toe links stop rear steer under brakes as they are monoball units so no toe flex.

You will also have to buy a load of GT3 cup shims.

I tried the rear arb at full stiff, but at high speed the cars not quite balanced and gets a bit twitchy, so have gone back to middle setting.
I think I run -2.2 front and only -1.8 at the rear with no front toe in. Feels great for fast road use and very planted. and on track will save your tyres over oem which kills edges. The added monoball toe links as stated also make the car more stable on big brake stops. Some people have more rear camber but after chalk tyre tests I went for -1.8.

If you want more camber you have to buy more parts to adjust caster as over -2.5 you cannot get the front in spec, so extra caster adjustment parts are also needed.

Tarret, TCP and RSS do some great kits depending how far you want to go. If you are very serious then stiffer springs and the dsc PASM control unit can be also added.

Edited by Porsche911R on Saturday 26th November 21:22

[gtsralph]

Depends how serious you want to be.. and your driving style

Some things to investigate..

http://rennlist.com/forums/gt4/932358-experiment-g...

Try Centre Gravity for set up, Chris has a lot of experience now of GT4s,

TPC Racing rear offset toe arm and DSC active suspension, amongst others

[Porsche911R]

I was going to post pics of some kits when I was on my main PC

here you go.

basic kit which will allow full adjustment for a street/tracked car.


More serious kit with monoball LCA ends and Caster adjustemt.

A great well thought out kit

[isaldiri]

For a reasonable baseline on a first trackday, I'd just turn the cambers up to factory max, very slight front toe out and set arb to medium front rear hard. You'll destroy your front tyres pretty quick but without harder springs I'm not convinced much more camber helps. The car would imo be pretty effective like that, albeit there is plenty one can do to make it better if you wish. If you're not happy with that, you can then start adding various bits and bobs. I wouldn't go mental on adding a ton of parts straightaway personally.

[Porsche911R]

I tried rear ARB hard and things get tricky at speed, although I liked it for ages that way.
great road set up though at lower limits.

But down craners at >100mph not so good ;-)

toe out on any car which see's the road is not a good thing to do imho.
not even the GT4 CS race cars has toe out !

Edited by Porsche911R on Monday 28th November 11:11

[thegoose]

I was instructing for Goldtrack recently and one of their regulars is really pleased with how he's improved his GT4. It did involve changing some arms for adjustable ones but I'm not sure of the detail. More importantly, however, was that for about $800-900 he'd got a re-programmed PASM ECU from somewhere in America which he thought was a very worthwhile and very cost effective modification.


NB, this was just a conversation in the signing on area, I haven't been in the car.

[BubblesNW]

thegoose said:

I was instructing for Goldtrack recently and one of their regulars is really pleased with how he's improved his GT4. It did involve changing some arms for adjustable ones but I'm not sure of the detail. More importantly, however, was that for about $800-900 he'd got a re-programmed PASM ECU from somewhere in America which he thought was a very worthwhile and very cost effective modification.


NB, this was just a conversation in the signing on area, I haven't been in the car.

Hi Marcus, he wasn't in a white GT4 and called Tim by any chance?

[isaldiri]

thegoose said:

I was instructing for Goldtrack recently and one of their regulars is really pleased with how he's improved his GT4. It did involve changing some arms for adjustable ones but I'm not sure of the detail. More importantly, however, was that for about $800-900 he'd got a re-programmed PASM ECU from somewhere in America which he thought was a very worthwhile and very cost effective modification.


NB, this was just a conversation in the signing on area, I haven't been in the car.

That's PHer Ravon. he's very positive about the DSC sport suspension module.

[Steve Rance]

I followed Tims car at Silverstone with the DSC fitted. Impressive. As is the RSS kit the Porsche911R kindly posted up earlier.

[Porsche911R]

Tims got every thing on his and 425bhp :-)
Must be the most sorted UK GT4 out there.

I see a silver one just had a load of work done and 425bhp tune up also.

[Steve Rance]

Tims car is very well resolved. He has unlocked a lot of the cars true potential. Very nice thing and great to see it and so many other GT4's out on circuit.

[JayK12]

Porsche911R said:

But down craners at >100mph not so good ;-)

Edited by Porsche911R on Monday 28th November 11:11

Bit slow that David :P

[Porsche911R]

lol I have moved my ARB back to the middle at the rear, and have not been since ;-)

I hate WOT down craners, always have, I tend to find rented book a track caterhams always spinning across your path down there ....

must be my age but I hate keeping my foot in down that bit.

[JayK12]

Porsche911R said:

lol I have moved my ARB back to the middle at the rear, and have not been since ;-)

I hate WOT down craners, always have, I tend to find rented book a track caterhams always spinning across your path down there ....

must be my age but I hate keeping my foot in down that bit.

Im the same mate and Im not old, coming out of redgate and staying flat and through craners is bum tingaling every lap, having confidence the rear isn't going to let go and you'll make it on the brakes in time for the old hairpin lol.

[n12maser]

Porsche911R said:

lol I have moved my ARB back to the middle at the rear, and have not been since ;-)

I hate WOT down craners, always have, I tend to find rented book a track caterhams always spinning across your path down there ....

must be my age but I hate keeping my foot in down that bit.

I was at Donnington a few days ago, an XR2 messed on Craners and ended up upside down on the gravel at the bottom. Luckily was track prepped with a cage. Track was dry. Granted not a GT4!!!

[Cheib]

I know sweet FA about setting cars up for track as I don't do track days (time not desire stops me)...in this vid https://www.youtube.com/watch?v=L9-Sr8RPty4 there's mention in the section towards to the end when Harris is talking to AP that they tweaked the Aero a bit to suit Harris's desires.

[Porsche911R]

yes they put the Rear ARB to full stiff and yes it's fun and great on the road.

But on track it gets twitchy and at Anglesey you seem to be adding OP lock more than one would like out the bends, fun but slower ! :-)

[jackwood]

OP, my advice is run it stock for the first trackday and then see if you want to change it.

8000 miles and a few trackdays later (and still on the same front tyres) we are still running ours bog-standard out-of-the-box settings and hardware.

It's the internet, so everyone is right, but I'd save yourself some cash on buying parts for the car, go to a trackday, try it out, and then if you absolutely HAVE to spend money on something, spend it on tuition.

Jack

[braddo]

Porsche911R said:

yes they put the Rear ARB to full stiff and yes it's fun and great on the road.

But on track it gets twitchy and at Anglesey you seem to be adding OP lock more than one would like out the bends, fun but slower ! :-)

That's may be because you set up the front of your cars to be very pointy, and you did that before you set the rear ARB to stiff. I expect that for dry track driving there is a more optimum setup than your current which involves the ARBs being set stiffer.