The setup guides you quoted are wrong. It's really simple:
You are correct. Increasing the weight on one end of the car always increases the grip on that end of the car. Nevertheless, my statements are correct as well. I will try to give a short explanation as to why that is.
I guess inertia. When turning, you're trying to get all the weight at the front to stop going forward but to change direction. The more weight at the front, the more the front will want to keep going straight instead of turning therefore understeer. There more weight on the rear means the opposite: the front has no problem changing direction while the rear wants to keep going straight rather than change direction which means oversteer.
Wow! So much misinformation in one post.Hi guys,
Chriss, nice work, keep it up, thank you.
Heitor, thank you, I've been running with too soft bars.
Now... Differentials.
You're doing it all wrong!
If one mashes up the "Loud Pedal" coming out of a tight corner, what ever the diff ramp (lock setting), if the rears light up... be prepare to go full opposite lock... wrong driving technique or the style of our sport for the idiots.
"By limiting the slippage between the rear wheels, the differential can have a profound impact on the car's handling. The rule of thumb is: the more the diff limits slippage, the more the car will tend to go straight or understeer -- --up to a point. On the power side, if enough torque is applied to spin both wheels, the car will snap into oversteer."
(http://www.intothered.dk/simracing/differential.html)
That mean, on a long fast sweeper, at 100% lock, the inside rear want to rotate at the same speed the outside one is. The rear axle wants the car to go straight. 100% lock, the car will not turn. At 0% lock, it will turn all we want but it wont accelerate out of anywhere (smoke show?). Just one more balancing act!
Setting lock percentage by how the rear end pops out is bad. Wrong driving style. IRL, bye bye rear tyres in just a few laps.
Always set your diff while driving with your head... not sliding, all wheels well planted.
To finish, there are a lot of very technical books out there but, for many readers, going through those can be quite harsh.
Drive to Win - Carroll Smith
Tune to Win - Carroll Smith
How To Make Your Car Handle - Fred Puhn
Going Faster - Carl Lopez
Many years ago, I learned everything from a little book that was a breeze to read: Four Wheel Drift by Steve Smith. The guide that came with Grand Prix Legend. The people who did not go through it found GPL undrivable. The racers who did... learned to drive.
Exert: "Alison Hine uses the tire temps to help adjust the differential. Taking a reading coming off the Parabolica where you’re most likely to get wheelspin, she looks at the temp of the inside (RR) tire. If it’s higher than the outside tire temp, which would normally be the hotter of the two, she knows she’s spinning the inside tire, and adds a clutch or two until the temp drops. She knows she’s gone too far when both tires break loose together, sending the car into snap oversteer. Then she removes one clutch the inside tire should now begin to spin just before the outside tire breaks loose."
*** EDITED ***
In Grand Prix Legend:
--- High ramp angles equal Low locking %
--- high clutch # roughly equal to high preload %
---Augmenting preload "mainly" sets the minimum level of locking so you don't get an open diff during the transition between power and coast.
--- Adding clutches Modifies how fast that transition, that locking happens.
Gilles
*** Open mouth - insert foot - echo Internationally ***
Yes, that's how it works. I set the power lock just high enough that I can accelerate out of corners with very little steering input and without having to countersteer. For touring cars and GT cars that approach usually leads to values between 20 and 40%. F1 cars and similar are usually between 5 and 10%. Coast lock depends a lot more on the car and the other setup parameters. I use everything between 0 and 100%.
I typically keep it very close to the minimum. Higher values just make the car understeer mid-corner and oversteer on exit. Sometimes I use very high values to cure oversteer on the brakes that can't be fixed even with coast lock at 100%. Of course this also leads to a very oversteery car on exit.
It's still essentially the same thing and it's generally possible to convert these parameters into percentages of lock. You should check out the differential calculator in the thread I linked to before.
Which mean this guide here is also wrong. Again, thanks Dude.
My link doesn't show that at all. Please read carefully. I will now go through your post and point out everything that's wrong with it.
The oversteer you'll get can be very different depending on your differential settings. It's not all the same just because your rear tyres are spinning.
As mentioned before, a locked differential will give you more rotation under power unless you are driving way under the limit. The open differential is the one that wants to make the car go straight. If the car snaps, it's usually because the driver was applying too much steering lock in a failed attempt to reduce understeer. A car should never snap!
Actually, that's exactly how I always set up my car. Maybe I'm the one doing it wrong? And driving with all wheels planted doesn't work on a race track. Not when your goal is to go fast anyway. You absolutely need to slide at least a little bit to achieve fast lap times.
Tyre temperatures are a terrible way to adjust the differential. You should be able to feel how the car responds to throttle input on corner exits and make appropriate changes. In my opinion it's on of the easiest things to feel. Monza is a bad example anyway because you won't get wheelspin in Parabolica on the modern version of Monza. The exit of the first chicane is where you are most likely to get wheelspin.
You just contradicted yourself
It does both.
Your statement directly contradicts Newton's laws of motion that form the basis for classical mechanics we still use today. Somehow your magic tyres produce heat without any friction. Fascinating! I am glad you like my book. Thank you for your interest on the behavior of differentials.
