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No one was dissing the formula, at least I wasn't. Formulas are fun. I just said it should have a factor for compound, which still sounds reasonable to me. If it works for you, then great. Each to their own and the world is a richer place.

I set my pressures by checking telemetry, and camber by a combination of feel and comparative lap times. I'm sure there's someone out there who uses the celestial calendar, or maybe even a dart board.

LMAO off at Dart Board

Hi there i was wondering how you find out what the USR and the LSR are i thanks

@honurbly -- Just go to the Springs section of the Tuning and move the slider all the way to the left (LSR) and all the way yo the right (USR). Basically the min and max of the spring slider. These are different for different cars/builds, thus, check after build process. One caveat,,,,,If you do not have race springs you do not get these values.

Edited by user Tuesday, April 29, 2014 6:14:13 AM(UTC)  | Reason: Not specified

thanks heaps man really appreciate it man

I guess I was dissing it.

Look Im glad it helps you. And Im glad it helps many people. But Im not sure how you determined this to be "accurate" or "the truth" or that it gives you "perfect tire temps" at all. It drives better then the settings you had? Ok fine. But if you lowered them some and adjusted camber to match, would that be perfect too? Or if you raised it a little and re-adjusted would that be perfect too?

Are they perfect in the sense that you can set top 10 times? Or perfect because they are extra stable when lobby racing? Are they perfect because they are easy to drive? Its a matter of opinion. And mine is that, outside the premise of balancing somewhat based on weight distribution, this is a waste of time. Sorry, just my opinion.

I have a problem that maybe someone can address:

The 9.8 figure for gravity is metric: 9.8 m/s^2

The LBS, USR, and LSR values are English units: lbs, lb/in

How can you justify mixing incompatible units of measurement like this? Why are you not using the English gravitational constant of 32.2 ft/s^2 or some variation thereof?


EDIT:

And looking more closely at the formulas and working through the units:

PSI = (WD%(LBS)) * (9.8/(USR-LSR)) + 14.7

Convert the 9.8 m/s^2 into English units, 32 ft/s^2 or 386 in/s^2...

Now the formula with units only:

lb/in^2 = lbs * ( in/s^2 * in/lb ) + Constant (constant has no units)

lb/in^2 = in^2 / s^2

^^^ That doesn't make any sense. The basic unit conversion seems to invalidate the notion that this is scientific math being applied. What's going on?

Edited by user Saturday, June 21, 2014 6:27:11 AM(UTC)  | Reason: Misc.

It's an old formula I made years ago when I was like 13-14 year old! So don't get your knickers in twist.
And anyway, I have a new one which is much better.

Rest assured, no knickers are twisted on this end. I was just hoping to get some clarification.

Care to share your new one?

not atm

Count me unsurprised and less than enthused. I guess I'll go figure something out that's actually based on physics.

Edited by user Monday, June 23, 2014 8:41:39 AM(UTC)  | Reason: Not specified

Count me shocked. At least I've shared what i made when I was 13-14 years old. You make anything like that at 13-14 years old, you got anything to share, no? Oh, not surprised.
I'll put it simple... how dare you have the audacity to come into this thread, making me seem as if I'm the bad person. If you don't like it, don't use it! I share what I make to help others, if it helps them then good. But, people like you who have no respect for others who help really need to jog on.
Have a great day... not! =]
RR

Fun racing last night... we need to have more HSV battles soon

haha funny thing is that real world input usually is 1 of 2 things a) unstable b) slower than trial and error

the formula that is posted is good if you take it back to the older forza games , for this one its a few psi off here and there on certain cars for fm5 but going off the results RR has posted with his new formula i can say he has got it down.. no need to be arrogant towards someone who posted something for everyone asking nothing in return ... an old saying fits this " if you dont have anything good to say , dont say it"

RR if you could give an update on your new calculations that would be nice :)

I agree with all this but I just run round the nurburgring with telematary on then try and get 32psi out of the tires from lap 2 -5 and then also try and get the temps as balanced as possible across the tire under braking and acceleration if your camber is high you will always get a little peak on the inside but it should settle down in the straights . As long as your getting the best footprint on the road from the tire it should be all good . Especially under braking and accel then your stoping distance and accel should be spot on. If I was good at maths I would use your theory but I like to do it the dirty way on track and feel it as you tune and move things about till you know you can't get any more out of the car then I am happy :-) . Usually takes me about 10-15 laps on nurburgring to tune a car properly then it should be good on most tracks !

Happy tuning :-)

Look, you're getting way too defensive and blowing this out of proportion. I've actually done nothing to make you out to be a bad person - I merely posited a couple of reasonable questions and asked that you share the solution you claimed to have. You really can't accuse me of making you look bad for having accurately low expectations for your behavior (i.e. being unsurprised when you refused to share).

Again, I didn't demand that you give anything out - I asked. I didn't even say I didn't like your formula - I asked how it could make sense.

If you think that asking reasonable questions is audacious, then I don't know what to say to you. You should probably just take a deep breath and calm down.

No. #1
"Count me unsurprised and less than enthused." - That is basically claiming that your not surprised that I'm not giving out my new formula hence, this is why I've typed about sharing. Why? Because your not surprised that I'm not SHARING it which to anyone, this would suggest that your telling me I never share anything. But wait, I'm sharing a load of open source tunes, no one asked me but I did it to help the community! So, saying what I quoted is making me seem like a bad person in other words, self indulgent which I'm not!
"I guess I'll go figure something out that's actually based on physics." - This is an insult. I know it's not accurate, I was 13 - 14 years old get that? Of course it isn't going to be accurate! You know anyone that are on Forza, who are 13-14 years old, making formulas? Do you?
RR

Off topic I know but I would have thought the aim of adjusting camber IS to get the inside peak on the straights which indicates the tyres are at a slight angle to the road. Then when cornering the outside tyres flatten out to get the best grip under cornering and when back on the straights you get the inside peak temps again.

Depends on how far you want to go into it. Both of use are correct I think, for the peaks of the out - mid - in to be balanced in a straight line, your gonna need a lot of velocity and/or downforce. This wont be seem on many tracks though, hence why initially the peaks aren't balanced. (This is with high amounts of camber). Anyway, this game is wrong with camber,
example: How is -2.5 gripper than 0.0 in a straight line? But I guess we all just have to deal with it.
RR

Agreed yes sorry I forgot yo mention about downforce . Yes you will get a peak from time to time on the inside if the tyre wall which is fine as this proves we have camber to carry us through the corner with the best footprint , like I said I tune 90% for the nurburgring so high downforce in most higher classes is needed thus giving you more pull down on the car and increasing the footprint on the track , which also has to be countered with tire pressure too, as the more downforce and pull down on the car the more the tire will sag out at the sides because of the pull down of the car from downforce this also has to be countered with tire pressure to compensate as the rims will bang out into the track as you hit bumps and dips and jumps . Most people don't realise this which so increase bump stiffness or springs thinking they are bottoming out but this is not case if you see on telematary when running on the ring that the sprigs are going red at compression points this means you are bottoming out and need higher bump / stiffness or ride height to compensate , but if they stay green but you hear banging and the car joults about this means the rims are hitting the track through the tires as the pressures are to low so need to be higher due to rim ground out this is compensated through pressure adjust .

Like i said not many know this so a good tip for the comunity for free :-)

It's will help with the general car demeanour round the ring and bumpy tracks and make it more stable if you get the balances right .

Thanks

I'm really not sure why you keep getting so defensive over every question or comment I make. My only guess is that you're desperate for online drama.

Fact is, I don't have the stomach for it. I have far more important things to do than get dragged down into your overly-emotional arguments over non-offensive things which you are finding offensive. I really hope that, as you grow up, you develop some thicker skin and learn how to handle critical questions with a little more grace and class.

Lets all hope that when you grow up, you become more independent.
FYI, you might find, I'm legally still a child =] Looks like a child is smarter than you NAGA lol!
RR

I almost didn't post a reply. I know this is a very old post, but this is the 2nd complicated formula of yours that l took the time to learn, and the results were just as disappointing. I know l've posted a couple of experimental theories, but l took the time to remove them once l learned they were flawed. The damp formula? Waaay off. Got the same results in your example, applied it. It was terrible. Checked example. Did it correctly. Plugged my numbers. Same result. Terrible. It's been a couple of months, so l can't recall my numbers, but it absolutely didn't work.

Fast forward to now. Got my camber right. Even pressure on all four tires (within .2 psi front to back) running even pressure. Good contact patch/heat. l just decided l wanted a way to find the optimal cold pressure. Worked it out on my Raptor and got like 42.5 psi rear..l skipped the front. l thought, "l'll try my Gymkhana." Then l realized...uneven upper and lower rates front to rear. So l used the same rate, just different WD's. Again...40, plus psi and like 28 psi. I figure it's because of the spring rates, and l'd circle back to it. Worked it out on my 22B sti..same stupid results(generally). 42 something or other and like 29. I thought l'd try it anyway since l burned an hour learning and testing...Performed as expected. Contact patch striping and flashing in strips. 15 psi difference....everywhere. Still, l thought l'd reverse it..nope. Worse.

I'm not trolling. I just wanted to give you some feedback. These formulas might work for certain cars, but they're way off for others. To save people time, you should tell them that. Everyone that's praising this formula..idk what to say. I'm upset because they sold me on trying it, but at the same time, l feel bad for them. Fyi..US rate/LS rate is irrelevant. You should work from front load/rear load. That's what the rates are based on. Yields a much better and easier tune. The upper rate is only relevant when finding damp..which is way simpler than your other formula. You just do your math from the top. Spring rate, divided by your US rate. Gives you a pct. The only time your upper and lower are relevant. Multiply your max damp by this pct, and there you go. Rebound. Bump set at your highest weight distribution. Effin' 9.8/US-LS..plus, blah blah blah...bro. Nevermind. I'm sorry, but l can't deal with time wasters. And the fact that you're so self confident, and have people backing you, and both formulas are broken. Close the posts, homie. Top Google result. Got me...again.