Base line set ups on GT cars
Base line set ups on GT cars
Author
Discussion

Steve Rance

Original Poster:

5,453 posts

254 months

Sunday 8th March 2015
quotequote all
the base line set ups on GT cars are just awful. Front end effectively disconnected from the rear with light, vaigue steering giving little feel and even less confidence to an inexperienced GT driver. Quite how Porshe's safety police are allowed to Ruin a potentially sublime chassis is utterly beyond me. The twerp who is responsible for this should be shot and burried in the same hole as the engineer who designed the PASM system.

No wonder some drivers are left a little confused and let down by the GT ownership experience.

if we must be subjected to insipid set ups then add a little more toe in for confidence by all means but for god's sake put some neg camber on the front end at least and make a token effort to connect it to the rest of the car. I've driven some awful set ups on GT3's before but nothing as utterly hopeless as the one that Porsche offer up to it's unsuspecting customers. If they insist on serving us up this drivel, then supply the car with a cheque for £400 so the owner can take the car somewhere after he's picked it up and get it done properly.

Rant over..

Edited by Steve Rance on Sunday 8th March 07:54

PorscheGT4

21,146 posts

288 months

Sunday 8th March 2015
quotequote all
I say this for every car.

The reply you get is "porsche know best, who do you think you are"

Quite a few people post this when I say change the geo.

So most people are driving about on st set up cars :-( makes me sad

Steve Rance

Original Poster:

5,453 posts

254 months

Sunday 8th March 2015
quotequote all
Agreed. A quick question. I know that your GT3 experience wasn't a great one for you. How much of that was down to set up do you think?

Slippydiff

16,009 posts

246 months

Sunday 8th March 2015
quotequote all
Steve Rance said:
the base line set ups on GT cars are just awful. Front end effectively disconnected from the rear with light, vaigue steering giving little feel and even less confidence to an inexperienced GT driver. Quite how Porshe's safety police are allowed to Ruin a potentially sublime chassis is utterly beyond me. The twerp who is responsible for this should be shot and burried in the same hole as the engineer who designed the PASM system.

No wonder some drivers are left a little confused and let down by the GT ownership experience.

if we must be subjected to insipid set ups then add a little more toe in for confidence by all means but for god's sake put some neg camber on the front end at least and make a token effort to connect it to the rest of the car. I've driven some awful set ups on GT3's before but nothing as utterly hopeless as the one that Porsche offer up to it's unsuspecting customers. If they insist on serving us up this drivel, then supply the car with a cheque for £400 so the owner can take the car somewhere after he's picked it up and get it done properly.

Rant over..
hehe

Morning Steve, is this out of the box "as purchased" ? or have you had the car measured and set up accurately to factory specs ?
If it's the former, its settings will be all over the shop (specifically, rear ride heights, rear toe and camber)

nxi20

782 posts

228 months

Sunday 8th March 2015
quotequote all
Agreed, the standard geo settings do the GT cars a huge disservice. I've always wondered if the quoted 'ring times have been achieved on the factory geo or do they tweak the settings?

When you compare the factory settings to the Kussmaul settings, the differences are huge. It seems to me that Porsche are trying to maximise tyre life with their settings; as if that was a top priority for a GT owner!

Ravi355

685 posts

253 months

Sunday 8th March 2015
quotequote all
So where would you go to rectify the problem? If you weren't hell bent on chasing 10ths of seconds (so no rose jointing, changing dampers, spring rates etc) and wanted to make the car better. FYI I tried a set up by jzm that made the car hugely pointy but the rear was really loose as a result.

Slippydiff

16,009 posts

246 months

Sunday 8th March 2015
quotequote all
Ravi355 said:
So where would you go to rectify the problem? If you weren't hell bent on chasing 10ths of seconds (so no rose jointing, changing dampers, spring rates etc) and wanted to make the car better. FYI I tried a set up by jzm that made the car hugely pointy but the rear was really loose as a result.
Yeh, JZM are good at that, it's precisely what they did with my first 996 GT2, and the end result was all but undriveable. Me and a mate now refer to such set ups as being "slow fast road set ups" biggrin

As Demon has said on herebefore, such extreme set ups are an utter waste of time on the road (great on track) as a simple "chalk test" on both front and rear tyres will show that running such extreme cambers on the road just compromises the contact patch to such a degree that the car has less grip, not more. Granted the turn in will feel "pointy", but thereafter you'll have less grip...... In their defence, when such set ups are referred to as "fast road", they do make the car feel fast !

There are several specialists who seem happy to tailor set ups to an individuals preference, Matt at Fearnsport and Chris Franklin are two that spring to mind.


Edited by Slippydiff on Sunday 8th March 10:18

PorscheGT4

21,146 posts

288 months

Sunday 8th March 2015
quotequote all
Steve Rance said:
Agreed. A quick question. I know that your GT3 experience wasn't a great one for you. How much of that was down to set up do you think?
I made it not to bad in the end, my issue was not so much the spring rates or geo it was more the front ARB stiffness and how that affected the steering wheel on every bump along with the long gearing I did not like.

on the road I ran the front ARB full soft in the end with about -1.5/1.8 camber up front and no toe. (too long back to remember now)

my car was set up at C of G but he set the front ARB harder than full soft and it was undrivable on bumpy roads at high speed.

My issue as I say was gearing and I feel this could also be the GT4 let down although peak torque on the GT4 is 1.3k lower than a GT3.
and I see the GT4 has the GT3 ARB !!!

I found on a road like the fosse way at speeds you should not being doing you had to slow down other wise the car would throw you into on coming cars.

Hit a small bump with your left wheel at the side of the road, that made the right wheel move due to the stiff ARB and then with the harder SUS the cars starts to get out of shape to a point at 120 leptons the cars moving 1/2 a car width across the road and all this while still trying to rev out in 3rd gear !!!

Smooth roads no issue, UK has no smooth B roads :-)

I had a love hate with it, right road awesome, wrong road frustrating, I live where the roads are wrong roads lol

Should have kept it, fitted a short final drive and some 3 ways and be £30k better off due to price rise lol

Edited by PorscheGT4 on Sunday 8th March 10:28

Slippydiff

16,009 posts

246 months

Sunday 8th March 2015
quotequote all
PorscheGT4 said:
I made it not to bad in the end, my issue was not so much the spring rates or geo it was more the front ARB stiffness and how that affected the steering wheel on every bump along with the long gearing I did not like.

on the road I ran the front ARB full soft in the end with about -1.5 camber up front and no toe.

My issue as I say was gearing and I feel this could also be the GT4 let down although peak torque on the GT4 is 1.3k lower than a GT3.
and I see the GT4 has the GT3 ARB !!!

I found on a road like the fosse way at speeds you should not being doing you had to slow down other wise the car would throw you into on coming cars.

Hit a small bump with your left wheel at the side of the road, that made the right wheel move due to the stiff ARB and then with the harder SUS the cars starts to get out of shape to a point at 120 leptons the cars moving 1/2 a car width across the road and all this while still trying to rev out in 3rd gear !!!

Smooth roads no issue, UK has no smooth B roads :-)
I'm extremely doubtful it was the ARB, in my experience it's more likely the ride heights were too low. As for your comments about being thrown into the path of oncoming cars : that's exactly what I experienced with my 996 GT3 RS. So bad was it, it limited the car's ability on anything other than billiard table smooth roads.

ALL my Mk1's set up properly (ie not slammed to the deck and not running "slow fast road set ups" that being big camber and parallel toe/toe out on the front) would drive the same stretches of road totally composed and at far higher speeds.

The old adage "compliance is king" is an apt one. Stiffly sprung, low slung cars have their place, but it's not on the UK's twisty B roads ........

A modern WRC car runs with a maximum of 10" (or is it 9" ? I forget) suspension travel. Even in Tarmac spec the cars will have at least 5" front and rear travel. A 996 (and I suspect a 997) GT3 will have no more than 3" on the rear, add in the usual saggy rear springs and you're down to 2.5", decide to slam it and you'll probably have less than 2" before you're riding on the bumpstops...... the front is a little better, but not much.

fioran0

2,410 posts

195 months

Sunday 8th March 2015
quotequote all
Steve...... LOL.
I am always surprised just how many cars are still on the geo that is given in the book. Given how long these have been around, and the talk you hear from most about these cars, I used to assume that almost every car would at least be using the Kussmaul settings as a baseline, since these are essentially the factory non-factory setup.
Its really horrible if you set it up the first way, as your post says.

Some of it may be down to the smoke and mirrors some of the set up shops layer around what they are doing to make it look like they have a unique insight. But thats for another rant..... or the same one we have every couple of years haha.



fioran0

2,410 posts

195 months

Sunday 8th March 2015
quotequote all
PorscheGT4 said:
on the road I ran the front ARB full soft in the end with about -1.5/1.8 camber up front and no toe. (too long back to remember now)
Running the front bar on full soft is the exact opposite of how to get the GT3 cars to work, and if you can get any sort of speed is the shortest way to see a "code brown".

I know it doesn't matter since you got rid of the car a long time ago. It's more a mention in case anyone reading in was thinking they would try that. There is few enough GT3's going around without sending them all off to the scrap yard via a full soft front bar.



PorscheGT4

21,146 posts

288 months

Sunday 8th March 2015
quotequote all
fioran0 said:
Running the front bar on full soft is the exact opposite of how to get the GT3 cars to work, and if you can get any sort of speed is the shortest way to see a "code brown".

I know it doesn't matter since you got rid of the car a long time ago. It's more a mention in case anyone reading in was thinking they would try that. There is few enough GT3's going around without sending them all off to the scrap yard via a full soft front bar.
maybe on track, but it made the GT3 usable on bumpy B roads, I did try every setting, putting it on soft had some neg effects but allowed it to run on bumpy roads at speeds far better. either way you are driving around issues, just have to pick which issue is better to drive around.

when it was stiffer it was great on smooth roads and an arse on B roads. at 85 mph the gearing was a fail and the bigger issue imo.
slow down for bends and the speed is too high for 2nd and way down to low in 3rd, then on B roads not enough room to then rev the car out in 3rd gear all the time.

That's all my personal experience on the roads I drive on, so it matters not what the car is, it did not work for me on my local roads. GT4 might be just as bad.
nothing more frustrating than not being able to keep a GT3 above 6k revs imo. And to do that you need less sharper bends and no tractors/horses on the roads and drive at double the speed limit !!

slodge

513 posts

185 months

Sunday 8th March 2015
quotequote all
Agree with all of this, my 6.2 GT3 on factory settings was horrible on track and completely confidence sapping. Thought I'd made the mistake of a lifetime. Post geo I just remember thinking WOW - what a machine. Predictable, responded beautifully to minor lifts on the throttle to get nose tucked in, balanced on the brake into corners, planted on exit etc etc. I didn't drive the 7.1 GT3 on factory setting, had the geo done before taking delivery so can't comment on that car, but can only imagine must be the same issue.

Forgive my ignorance but what are the Kussmaul settings?

Cheers

Slodge


Slippydiff

16,009 posts

246 months

Sunday 8th March 2015
quotequote all
slodge said:
Agree with all of this, my 6.2 GT3 on factory settings was horrible on track and completely confidence sapping. Thought I'd made the mistake of a lifetime. Post geo I just remember thinking WOW - what a machine. Predictable, responded beautifully to minor lifts on the throttle to get nose tucked in, balanced on the brake into corners, planted on exit etc etc. I didn't drive the 7.1 GT3 on factory setting, had the geo done before taking delivery so can't comment on that car, but can only imagine must be the same issue.

Forgive my ignorance but what are the Kussmaul settings?

Cheers

Slodge
Hi Simon, hope you're well ?

http://rennlist.com/forums/996-gt2-gt3-forum/30187...

And a brief (very brief) overview of the man himself :

http://www.patina9.com/3/post/2013/09/porsches-ult...

slodge

513 posts

185 months

Sunday 8th March 2015
quotequote all
Slippydiff said:
Hi Simon, hope you're well ?

http://rennlist.com/forums/996-gt2-gt3-forum/30187...

And a brief (very brief) overview of the man himself :

http://www.patina9.com/3/post/2013/09/porsches-ult...
Hi Henry,

I'm very well and you?

Thanks for above, some Sunday reading! smile

Cheers