Porsche 911 - How is it meant to be set up and driven?

[Celtic Pharaoh]

Hi all,

I've been driving various GT3 cars in Assetto Corsa but I'm not sure how the 911 is meant to be set up and driven. I usually prefer mid engine cars like the Ferrari, Lamborghini and Audi. I wouldn't say I'm slow in the 911 but I feel if I understood the proper way to set it up and drive it, it would have more potential perhaps. At the moment, I'm driving it like I drive the other 3 but I'm curious to know what are its tricks and secrets to unlock more of its potential. Thanks.

 

[Kasti]

The secret is the fact that it has an rear engine, that means engines mass and when accelerating, the engines power too are trying to squeeze the rear dampers and springs... mostly setups are used where rear springs were much harder than the front ones(quite the opposite to middle or front engine cars) to prevent from too much "sitting down" in the rear axle. The rear engine concept gives you lots of traction, but when you try too much it snaps and you turn in cycles.

 

[Giovaneveterano]

I usually brake earlier and I give a gentle and light amount of throttle before the apex, it helps in the turn in.

 

[Mr Deap]

The gas tank sit on top of the front wheel. Fuel load affect the weight distribution of the car. You have to setup the car around it.

 

[Celtic Pharaoh]

Thanks guys. I'll keep that in mind. I would've thought it would be better to keep the rear end softer than the front to provide extra grip at the rear but I can see how stiffening the rear would be more important to take out some roll and pitch caused by the lateral momentum the engine

 

[Brandon Wright]

One good trick in a rear engined car is to never fully let off the accelerator. Even under braking keep just a dab of throttle on, helps to minimize the sudden forward weight transfer which can cause the rear to come around.

 

[RasmusP]

Thanks guys. I'll keep that in mind. I would've thought it would be better to keep the rear end softer than the front to provide extra grip at the rear but I can see how stiffening the rear would be more important to take out some roll and pitch caused by the lateral momentum the engine

Please report back about your progress. I really like the Porsche but it's a bit tricky for me too!

 

[Giovaneveterano]

Beside the driving technique, I can't heat the front tyres and keep them warm.

 

[Celtic Pharaoh]

I tried having stiffer rear springs and it has helped stability with medium and high speed corners but like a highly taut elastic band, it violently snaps when pushed too hard so you still have to respect the limits. Higher rear wing can aid with the stability as well but of course you don't want to run too much at higher speed tracks like Monza or Spa. Applying left foot braking also helped so thanks for that suggestion @Brandon Wright
I suppose alternatively a much higher coast setting could work as well to limit the engine's longitudinal momentum under braking as well.

Thanks for the help and suggestions guys. It really helped

 

[Brandon Wright]

Applying left foot braking also helped so thanks for that suggestion @Brandon Wright

I was actually suggesting that you keep a little throttle on while braking, so brake with your left foot and keep just a dab of throttle on with your right foot to help manage the front-to-back weight transfer.

 

[Celtic Pharaoh]

Yes I know. Its a confusing term sometimes but I know what you meant

 

[Giovaneveterano]

Best explanation on how to drive it by a real driver (min 14:32)
-video expired-

 

[Tobiman]

This car gives me headaches. Forget the soft tires being completely useless in 95% of racing scenarios. That's already a given. This car doesn't like bumps at all and high speed cornering is its major weakness. Feels so unstable mid corner and when you increase the rear wing to bring it inline, you are met with absolutely horrible understeer.
With all that said, It's epic in the brake zone and corner exit acceleration is just bliss. My findings so far is that running 0 rear ARB helps with the high speed stability but it's not a night and day difference.
I have heard of people using F0 - R8,9 wing configuration at monza and the car is usually in the mid to high 1:47s. I can do mid 1:48s but my setup has more aero.
Rune janssen, who I think knows more than me thinks ACs tire model is holding the car back especially with the inability to run softs when pretty much every other GT3 can. Doesn't match the reality we see in real racing where the Porsche is actually sometimes kind to its tires when most aren't.
Also, Laurens Vanthoor did comment on the GT3 R being tough to drive fast at SPA 24hrs so I think AC gets some points in that regard. I just don't think it's this bad.

 

[HypoToad]

The rear engine concept gives you lots of traction, but when you try too much it snaps and you turn in cycles.

I know this only too well.

 

[2112]

The best advice I can think of is:

Slow in, fast out. The Porsche does not like late braking and will snap on you if you are not careful. The bias is also wonky on the Porsche- you have to have more rear bias than front. I race the GT3 Cup car in iRacing and usually set the bias at 48.3% to the front. This can cause the rear to lock if you try to dive into a corner but it will help keep the fronts from locking up.

As soon as you are at the apex you can mash the accel and watch the car behind you get smaller in the mirror. Just remember to have the whole car in the direction you want to go before putting the hammer down. Failure to do this will result in watching the following car come at you.

Use the brake to turn: Because of the weight bias you can use the brakes to turn. As you approach the apex dab the brakes a bit and turn the wheel. This will cause the above mentioned rear-bias weight transfer so common in Porsche's and if you know how to handle it , it can help you turn, thus exit, quicker. Use this only if you have practiced it, and are familiar with the technique.

When the iRacing GT 3 Cup series was running at the Nordschliefe I used this technique to win three races even though I started from the back on all three. Most tried to go into the corners too fast or could not get the weight to transfer properly to enter the next corner with an optimal line.

Practice, Practice, Practice: Because of my success in the series I have spent most of my time in the GT 3 Cup car, thus a lot of practice time. Every track requires me to learn how to set up the car and how to drive it. The stab-brake-turn is not very effective at Imola but works very well at Nords. Spa requires a lot more trail braking and late apexes than Watkins.

 

[Guillaume Francois]

Here is a setup I used with soft tires at Spa,
there is something i don't get, looking at springs and dampers (car engineer app) the front is stiffer (higher frequencies), the front splitter is set to 0, and at high speed (even when I try to set stiffer front bump and/or springs rate) the front ride height is still very low compared to the rear: 40mm or even under at the front and 60mm at the rear.
Here's a picture from a hotlap at paul ricard.

 

[Denis Betty]

I was told, that on rear engined cars, increase the slow bump on the front and increase the slow rebound on the rear. The idea is, that this will reduce weight transfer on lift off and therefore reduce lift off oversteer. I've tried it, with limited success.
Somebody else suggested higher than normal negative camber values on the rear. I guess because of the weight over the wheels? Anyway, whatever the reason, the high neg camber feels great to me, and improves my times. But then I'm not quick, so you'll have to try it yourself.

 

[dud]

I was told, that on rear engined cars, increase the slow bump on the front and increase the slow rebound on the rear. The idea is, that this will reduce weight transfer on lift off and therefore reduce lift off oversteer. I've tried it, with limited success.

This helps with the overly sudden nose dip, but it doesn't really do anything about weight transfer. Having said that...

Somebody else suggested higher than normal negative camber values on the rear. I guess because of the weight over the wheels? Anyway, whatever the reason, the high neg camber feels great to me, and improves my times. But then I'm not quick, so you'll have to try it yourself.

Keep in mind that the 911 has a simple struct suspension in the front. Camber changes drastically when the front suspension compresses. It is quite different between the front and rear in the 911. So, when picking camber you want to take into account that when you really need the camber the values are far from the resting values.

Which specific 911 are we talking about, anyway? 2017 Cup I assume?

 

[CobraCat]

Beside the driving technique, I can't heat the front tyres and keep them warm.

Max fuel load might help with that, more weight on the front tires.

 

[Guillaume Francois]

@dud I think it's the GT3 R 2016, but even if setups doesnt match the spirit could be the same for the cup i guess ?