The tiny collaborative tuning workshop

[vinz7531]

Hello,

As I've started learning tuning, I already noticed it can have a huge effect on some cars and that there are some generic paterns.
I also see in some discussions that many of us don't go into setup to fine tune their car.

The point of this thread is to share our knowledge of tuning with others working on examples. I think this will help newcomers and also increase knowledge of the others.

Here are some generic pattern that I've learned (thank's WFO Krypto and Viperconcept on youtube)
Springs: about 8% to 9% of the wheight of the car
rebound: between 6 (1000kg) and 8 (2000kg)
bump: between 4 (1000kg) and 6 (2000kg)
Having softer anti roll bar on the rear negates oversteer
Having softer anti roll bar on the front negates understeer
If you loose the rear of the car when baking and slightly turning put more brakes on the fron and less on the rear 1 ot 2% is enough
Spring, rebound and bump must be harder on the side of the car that has more weight (front engine sedans are heavier on the front, mid engine GT are heavier on the rear)

I'm not good on tire pressure and geometry

Differential: Can fix wheelspin problem while accelerating and wheel lock up on braking.
Must be tuned after the suspensions are OK, because suspension issues can also cause and fix the same issues.

acceleration: Lower the diff to get more time before torque is applied on the wheels. Lowering too much will also cause oversteer when exiting corners. Also lowers acceleration if lower.
deceleration: is generally low (17) lower it to avoid tire lock up while braking. Increasing it can be good for drift car.


Any one wanting to help with tuning questions is welcome, If someone is very active I will not consider the thread hijacked
This thread is not a supermarket, it's to exchange knowledge, If you simply want a tune without understanding it, use Forza's ingame function.


I'll start with a crap handling car: Lancia Stratos road version (homologated Showroom rally)
Try it with default homologation on Rio national circuit for more bumping fun
My tune in next post

Welcome !

Vinz

 

[WFO Krypto]

One thing I might add about the Diff. It is actually a "crutch" for your car geometry, or build, not being correct. If you have got everything right, you can run your Accel setting at 100%. I only have a couple B and C class cars that I have accomplished this on. The Decel Diff setting also is a crutch for corner entry. If you do not have the car correct, you will have to turn in down to get the car to "dive" into the corner. I find that if you have the car correct, you should be running this at 20 or higher.

 

[WFO Krypto]

Tire Pressure Rule of Thumb:

Stock Tires = 29.0 PSI
1 Upgrade = 28.5 PSI
2 Upgrade = 28.0 PSI
3 Upgrade = 27.5 PSI
Drag Tires = WHO KNOWS????? I don't use them

 

[vinz7531]

Tire Pressure Rule of Thumb:

Stock Tires = 29.0 PSI
1 Upgrade = 28.5 PSI
2 Upgrade = 28.0 PSI
3 Upgrade = 27.5 PSI
Drag Tires = WHO KNOWS????? I don't use them

Hi,
Thanks for the info
What is the consequence of lowering pressure?
- increased grip ?
- incresed tire wear ?

Thanks

P.S: I'll get the info for the stratos when I come home

 

[WFO Krypto]

I find that lowering the tire pressures in the way I build and tune cars, adversely affects the handling characteristics. That being said, you can lower air pressures to make it feel like you have fixed a handling issue. In doing that, at some point in time during your race, that feeling of "fixed" will go away. Tire pressures always change. If your cars handling seems to fade after a few laps, it's because your air pressure is not set correctly. The way that I build and tune my cars, I shoot for 32psi after the first lap, and even tire temps throughout the corners from side to side on the tires.

The handling of your car directly affects the amount of air pressure your tires change throughout a race. You want to come up to temp as quick as you can, and then the temps to level off and stay relatively the same.

 

[WFO Krypto]

Hi,
Thanks for the info
What is the consequence of lowering pressure?
- increased grip ?
- incresed tire wear ?

Thanks

P.S: I'll get the info for the stratos when I come home

I will build a stratos after work today. Never tried a Homolgated version. Might be interesting?

 

[vinz7531]

Hi here's the info on the stratos (showroom rally)
PI =525
power 176 kw (slight boost)
weight 993kg (slight increase)
weight distribution 46% front (54% rear)
RWD

value not marked are default

tire pressure front (f) 2.0 kg, rear (r) 2.0 kg
camber f -1, r -1
toe f 0, r -0.1
caster 4.7°

Anti roll bar f 19.46, r 15.00 (to correct oversteer)
springs f 73.9, r 74.8 (rear is softer than it should be to correct oversteer, springs are slightly softer than usual to deal with bumpy circuits)
rebound f 5.8, r 6 (rear is softer than it should be to correct oversteer)
bump f 4.2, r 4.3 (rear is softer than it should be to correct oversteer)

Hope you'll enjoy it

 

[WFO Krypto]

I built one last night. I shared it.

Tuner: WFO Krypto
Tune Name: GTplanet

I post the numbers tomorrow morning.

 

[vinz7531]

I built one last night. I shared it.

Tuner: WFO Krypto
Tune Name: GTplanet

I post the numbers tomorrow morning.

Hi, I took some time yesterday evening to bring my Stratos around the COTA (My favorite test track that contains everything). I also tested your tune.

Conclusion: Both tunes are vastly superior to the default one, but I am very annoyed to say so but your tune is beter
it has a better stability at corner entry.

Note that the Stratos is a car to be respected and has a very playful temper. Both tunes still preserve that

i'd be intersted to have the tune values and if possible the upgrades (mine has 1.14 cornering while yours has 1.17)

Vinz

 

[Felix]

Thanks for starting this thread. I only started playing FM7 a few weeks ago and as a wheel user coming from GT-Sport, I have had to totally learn a new way to drive, as the cars really hate it when I attempt trail breaking in a corner.

 

[vinz7531]

Thanks for starting this thread. I only started playing FM7 a few weeks ago and as a wheel user coming from GT-Sport, I have had to totally learn a new way to drive, as the cars really hate it when I attempt trail breaking in a corner.

Hello Welcome to Forza Community.
Some cars are unstable upon braking, either due to brake balance being too much on the rear or rear suspensions being too soft.
If you have any exemple of a car that causes a problem to you, I can give it a go and tell you what I think.

P.S: curently I am tuning the Lotus Exige because it becomes unstable when I release the brakes. probably rear bumpers too soft.

 

[WFO Krypto]

Thanks for starting this thread. I only started playing FM7 a few weeks ago and as a wheel user coming from GT-Sport, I have had to totally learn a new way to drive, as the cars really hate it when I attempt trail breaking in a corner.

I never have an issue trail braking. The issue you are having is with the way you have your car built and/or the way you have it tuned. If you are not trail braking, you are not fast.

 

[Felix]

I'm having to brake hard before the corner and then let off the brakes and the car go round the corner without horrific understeer happening. The way I have to drive the cars in FM7 feels so different to what I am use to in GT-Sport (which I will have assists off).

 

[WFO Krypto]

I'm having to brake hard before the corner and then let off the brakes and the car go round the corner without horrific understeer happening. The way I have to drive the cars in FM7 feels so different to what I am use to in GT-Sport (which I will have assists off).

You have got too much brake bias to the front. You need rear brake in the car to trail brake. As you start to drag the brake, by having rear brake in the car, it will pull the front of the car down and give it front grip.

 

[Felix]

You have got too much brake bias to the front. You need rear brake in the car to trail brake. As you start to drag the brake, by having rear brake in the car, it will pull the front of the car down and give it front grip.

Thank you for this info.

As you can see in my Avatar, I own and drive a BMW Z4MR and when I drove the Z4MC in the game, I was stunned just how "off" and different the car felt to what I feel in real life. Yes there are some key differences between the E85 and E86 M's , but because the Z4 was designed as a Roadster first, it means the Roadster is actually a very stiff chassis/body in it's own right. This is why the Roadster is actually lighter than the coupe, as there is no additional beams installed to help stop body flex, like you would see on the E46 M3/M3 Covetable's.

Anyway back on topic, the Z4M felt really bad to me and it was boarder line un-drivable. When I followed your advice earlier today, it was starting to feel closer and closer to what my own car feels like when I am Hooning around on UK B-Roads. The rear end now behaves predictable, but will step out if you get too aggressive on the throttle. I have also been tweaking in some tiny amount of deadzone in the brake pedal, so I can start to put a bit of pressure on and the brakes mimic how the brakes feed into strong breaking, rather than there being a sudden grabbing of the brakes.

With the Z4M's (and the E46 M3's) the S54 is an electronic (fly by wire) throttle and when you press the sport button, the only thing that happens is the throttle response sharpens up VERY dramatically. This makes the Z4M's a very Jeckle and Hyde like car. In normal mode, the car is a great motorway cruiser, but with the sharper throttle, it really flipping shifts! Anyway, I spent time fine tuning how the throttle reacts and it was easy to get it to behave like the "Sport" button has been pressed on.

Now, thanks to you telling me about adjusting the brake bias, I suddenly am able to drive the Z4M in the game, drive like my real car and focus more on the racing around me, rather than being distracted by how "off" it feels. I'm also now able to make small corrections with the brakes in a corner and make the turn, rather than understeering into a wall. It's a really great feeling when a car you own and drive is in a racing game and it is able to feel (to the best of my low abilities) spookily similar.

Before I had my Z4MR, I owned a heavily modified Subaru Impreza P1 for 5.5 years, which was a limited UK edition model of the 2 door Impreza, that was designed and engineered by Prodrive, who were the people than ran Subaru's WRC team. The 22B was done by STi in Japan and was based on the actual WRC cars that McRae and Burn's were racing in '97. After speaking with a number of people in the P1 owners club, who had both the 22B and P1, I knew what the key differences were between the way the cars behaved on the road and track. By having the confidence to alter the bias etc, I was able to make the 22B become as twitchy as it is in real life. I had to sell my P1 in '16 due to health problems with my lower spine, which had stopped me from driving for a few years (until around 12 months ago) and the car was rotting away on the driveway. Because of this, what I remember the 2 door Impreza (in Japan they had a 2 door model called the Impreza WRX STi Type-R , which is what the 22B and P1 are based on) is not as "fresh" or accurate as I have attempted with the Z4M.

Currently, I am now slowly altering the brake Bias on my all time ultimate dream car, the Ferrari F40-LM Comp, as I'd had a pig of a time getting it to drive (well brake) smoothly.

I am only making small single changes each time, as it means any improvements I get, I know exactly which change did it, rather than making loads of changes at once (like a real race team would typically do).

Even before you guys advised me about the brake bias, I had really been enjoying the game, due to all the different car classes and that I could basically use race street cars and find this just as fun as the full blown race cars. I am still only doing offline content, but I'm about to hit level 100 and am close to finishing every race series in the single player content. I hope in the next couple of months, to attempt online racing in FM7, but after seeing so many YouTube videos on what open lobbies are like, I am worried I will just get rammed off the track, just like the AI drivers seem to do.


Forza Motorsport 7 has really surprised me. Previously, I had left GT5 on the PS3 and got myself a secondhand Xbox 360 and a copy of FM4, which I thought was actually better and more fun, this is after I had gone from a Logitech G27 wheel setup with GT5, to a standard 360 controller. While GT5 had better graphics (not by that much), but it was the quality of the sound in FM4 that was so much better than the horrid engine noise in GT5). While GT-Sport is very different to previous GT titles and while it's much better now with all the free updates, it's single player is still really subpar when compared to FM7.


Quick edit - It is also uncanny how they really got the bark of the S54 engine really spot on. Best of all, I can also hear the difference between the E46 M3's S54 and the Z4MC's S54. My dad owned (until last summer), a E46 M3 Individual Convertible for the last 7-8 years, so I was really impressed how they had different induction tones in the game. (the E46 M3's have a different air box design compared to the Z4M's. Parts used on the Z4M, are off of the E46 M3 CSL, bar the carbon airbox, which is why there is a difference in induction tone and the slight difference in power)

 

[WFO Krypto]

Felix, are you driving your cars stock out of the box, or are you upgrading them?