I have been ruining like crazy in my 93 Cobra and reading up on everything I can and I still for the life of me can’t figure out how to set my tune up. I know all the basics like always run negative camber and all that but when it comes to fine running I am lost. I get a basic tune going and the car feels good but I know there’s more I just have no idea how to get it. I have no idea how to check of my camber and caster are good and I have no idea how to read telemetry for spring rates and all that. Like I have my springs set to xxx but how the hell do I know if I need to go up or down and once I do what else do I need to change? It’s like I’m going in circles and getting nowhere. Can someone just explain to me how to check everything and how am I supposed to know if I need to go up or down. Like if my camber is good but my caster is crap then it doesn’t really matter, but I have no idea how to check my caster or where to go with it. And once I do should I also adjust ARB? And how do I know where to adjust that to? I am driving myself crazy with this.
I thought you might have found this already…
http://forums.forza.net/turn10_postst221_Tuning-Guide.aspx
Apologies if I’ve posted the link the wrong way.
When on track (testing), press up or down on the D pad, this brings up telemetry. Press left and right to scroll through the sections. Press right five times and you should come to the section which includes cambers. Find a track with a longish corner where you can hold the speed whilst going round it at race speed (I use Monza short, using the long corner before the pit straight), whilst being able to watch the camber numbers. On the side you’re leaning on, you basically want just into the negatives on both front and rear. On this section you’ll also see the tyre (UK spelling) pressure. Everyone has their preferences but I go for as close to 31psi when up to temp (a few laps). Anything 32 and over tends to cause under/oversteer. It’s a bit harder to explain the exact negative you want and which reading to go on for entry and exit etc, but if you get the base set as you’re holding speed around the corner, that should get you started.
You could press right again on the D pad and you’ll have tyre (UK spelling) temperatures. After exiting a corner at race speed, you want the whole tyre being the same temperature, as close as possible. If the outside of the tyre is hotter, you need more negative camber. If the inside is hotter, you need to add positive camber. You have to be quick to read the temps thought, literally just as you’ve exited the corner. The insides of the tyre should be hotter on straights, you only need to read cornering temps.
I guess the rest is down to your preferred driving style.
Caster is hard to define as it was never really proven that it does have a real effect in this game. General rule of thumb is more caster requires less negative camber and vice versa. It will have a small effect on your turning radius and straight line speed and grip.
Camber should be adjusted so that when taking a corner, the side that is under pressure should reach as close as possible to zero… You will find the sweet spot when the tires will stop skreeching and when you have good turn in and cornering grip.
Spring rates are personnal preferences. Some like it soft other stiff. Between 400 to 600 for lighter cars to heavier. Up to 700 for really heavier car. Adjust your spring rates in order to control weight shift on accel and decel and avoid bottoming down.
There is no magic number to give you as tuning is really different between different tuner.
Springs and camber is really track specific. Camber should be one of the last thing you adjust since changes done to your dampers and springs will affect them.
Theoretically,
@OP, Camber is applicable at all times.
Caster is progressive increase of camber as the steering wheel is turned. At high speeds, FM limits how far the steering is turned (unless sim steering is used) therefore caster does not have a significant impact. Caster plays a bigger roll in slow corners. It is a method of adding mechanical grip to the front wheels for mid/high steering angles (or mid/low speed corners). I’ve heard that for the wheel users higher caster makes the car harder to turn; that is because the wheel is being forced to do more and it is pushing back.
Caster will ADD additional camber to the outside wheel BUT will REMOVE camber from the inside wheel.
eg. If camber is -2.0 and caster is 0.0, then the camber for both outside/inside wheels will be -2.0 through all steering angles.
eg. If camber is -2.0 and with caster the camber for outside wheel could become -2.0-(3.0) =-5.0 and inside wheel -2.0+(3.0) = +1.0 in a slower corner > this is an exaggerated example; math is not this simple. This example is just to illustrate the point that higher caster will lead to higher outside wheel camber when the wheel is turned.
However this does not mean high caster is always better; there is a good working range for everything.
So my strategy is to set camber for mid/high speed corners then add caster for additional camber in mid/low speed corners. Higher caster for no-aero cars and less caster for high downforce cars is what I typically employee in my tunes.
As for springs/arb/dampers, general rule that I use is STIFFER = FASTER response but nervous controls & SOFTER = SLOWER response but SUPPLE ride. Slower corners like softer suspension but faster corners benefit from stiffer suspension . . . so it is always a trade off since all tracks have both slow & fast corners. If downforce is available, then lean towards stiffer suspension.
From telemetry, as long as the suspension is not bottoming out too often (0.98 or greater), then you are OK. Occasional bottoming out is acceptable for bumps BUT not in mid corners.