Porsche 911 turbo (993) engine swap tune help
- Thread starter Jpdoyle12
- 6 comments
- 5,479 views
- 15
Of course.
This is a highly difficult car to tune and I am not surprised no one from the regular tuning "gurus" was capable of taming it.
So I sat down myself, even though I don't really have the time and the result is below.
Drives like a charm, you might forget it's a RR Porsche!
Edit: brake balance is -2 (more on the front).
This is a highly difficult car to tune and I am not surprised no one from the regular tuning "gurus" was capable of taming it.
So I sat down myself, even though I don't really have the time and the result is below.
Drives like a charm, you might forget it's a RR Porsche!
Edit: brake balance is -2 (more on the front).
Last edited:
- 832
- United States
In the current broken physics engine ride height is king. So if you need stability start at like 150mm/155mm or something like that.
The "pendulum swing" under braking can generally be addressed with uniformity in spring %'s and high anti-roll bars.
These are just rules of thumb though and there are plenty of outliers. That swap is the one I want more than any in the game, so of course I'll never get the engine, lol. Hopefully Ivan's tune above helps
The "pendulum swing" under braking can generally be addressed with uniformity in spring %'s and high anti-roll bars.
These are just rules of thumb though and there are plenty of outliers. That swap is the one I want more than any in the game, so of course I'll never get the engine, lol. Hopefully Ivan's tune above helps
- 15
Hi Pizzicato @Pizzicato1985
Ride height is strictly dependent on the car you are tuning but a general rule of thumb, and extreme oversimplification is that lower ride height gives stability of load transfer, whereas higher ride height gives grip.
This car has issues with load transfer, rather than grip.
Also, the oversteer under heavy braking is very easily fixed. It has nothing to do with spring uniformity, if you try that, you will likely make it worse!
The way you fix that is brake bias and, more crucially, softer rebound on rear. The reason you get heavy braking oversteer is the load transfer to the front, and making front bump stiffer will open a can of worms... so the easiest alternative is softer rear rebound.
Hope this helps your understanding of basic vehicle dynamics!
In the end, there is a reason I have tuned the car that way and I will be quite surprised if any improvements are easily done. Though you or anyone else is more than welcome to try! 🙂
Ride height is strictly dependent on the car you are tuning but a general rule of thumb, and extreme oversimplification is that lower ride height gives stability of load transfer, whereas higher ride height gives grip.
This car has issues with load transfer, rather than grip.
Also, the oversteer under heavy braking is very easily fixed. It has nothing to do with spring uniformity, if you try that, you will likely make it worse!
The way you fix that is brake bias and, more crucially, softer rebound on rear. The reason you get heavy braking oversteer is the load transfer to the front, and making front bump stiffer will open a can of worms... so the easiest alternative is softer rear rebound.
Hope this helps your understanding of basic vehicle dynamics!
In the end, there is a reason I have tuned the car that way and I will be quite surprised if any improvements are easily done. Though you or anyone else is more than welcome to try! 🙂
Last edited:
- 832
- United States
Agreed... when the physics aren't bugged. Right now the physics engine is riddled with bugs and 9 cars out of 10 want a high ride height even though it makes no logical sense. Like you can't use real world physics and tuning principles in GT7 since something is terribly wrong with the modeling. It is being covered-up with downforce (check any of the 50's roadsters like the Aston DB3S, D-Type, etc to see how broken the physics are since there's no way to add downforce as a band-aid)
I can't speak to the 930/RSR swap in particular since it's just luck of the draw what engines you get, so you're probably 100% right for this car/swap, I was just speaking about how tuning works in a broad sense after patch 1.23 (when one issue was fixed and many others were introduced). If I ever somehow get ahold of that engine I'd be glad to revist this topic though.
- 13
- United States
After waiting some time for someone to try it for themselves too, I eventually came to something similair by accident lol not knowing the physics well at all. I just found a softer rear, especially the rebound as you say, helped tremendously. Your tune is perfect though, the car actually drives like a normal vehicle now it’s kind of insane. Tried your tune with higher power too, and it still handled it, although not as well of course. Thank you my friend 🙏
- 15
Many thanks both!
@Jpdoyle12 glad to help!
You are right, this tune is for this power, if you want to raise the power, grip becomes a bigger issue, so you must raise the ride height, but that will worsen the load transfer, so the entire tune needs to be revised.
@Pizzicato1985 I have to disagree with you on the physics being broken. My tunes adhere to the same principles and they almost always work very well, even with extremely low ride height.
Now why people's tunes are not like this? Good question, I think that most are overpowering the frame significantly.
An example, for some reason people are adding balast, when it might not be needed, like when they need to reach certain pp level they increase both weight and power (!)
Doing so, the problem of their cars becomes grip, even if it hasn't been initially. You are right, downforce directly masks that, but not because physics is broken, but due to the fact that it provides the grip that most tunes need, so you can get away with ballast, or higher power, without noticing they create issues.
To put it simply, if you do not overpower the frame, or add too much balast, you can use lower ride height. Try reducing the stock power on some cars and you might get surprised.
@Jpdoyle12 glad to help!
You are right, this tune is for this power, if you want to raise the power, grip becomes a bigger issue, so you must raise the ride height, but that will worsen the load transfer, so the entire tune needs to be revised.
@Pizzicato1985 I have to disagree with you on the physics being broken. My tunes adhere to the same principles and they almost always work very well, even with extremely low ride height.
Now why people's tunes are not like this? Good question, I think that most are overpowering the frame significantly.
An example, for some reason people are adding balast, when it might not be needed, like when they need to reach certain pp level they increase both weight and power (!)
Doing so, the problem of their cars becomes grip, even if it hasn't been initially. You are right, downforce directly masks that, but not because physics is broken, but due to the fact that it provides the grip that most tunes need, so you can get away with ballast, or higher power, without noticing they create issues.
To put it simply, if you do not overpower the frame, or add too much balast, you can use lower ride height. Try reducing the stock power on some cars and you might get surprised.
