I have a Porsche RGT tune that I got from this program within 20-30 minutes on the previous page. While I still think that the car is underpowered, despite having a nearly reverse weight distribution, twice as much HP (though very little torque compared to the grip of the tires) and a redline about 1-1.5K higher... it drifted perfectly for me without trial and error in the tuning. If you're desperate to see what a car tuned by this method feels like, by all means, use it. It's not my best however, I've done this with a Dodge Challenger '70, SL65 AMG, Fairlady 2000, Nissan 350Z Z tune and S tune, Skyline GTS-T, Jaguar E-Type and many more. My goal is to provide quick and easy tunes that I do not need to test, and can drift reliably and comfortably without much effort or worry. It does not provide the "Fastest" drifting for some cars, but it appreciably reaches it and makes the cars almost instantly easy to manage. I never have a problem with not being able to drift a car once it's tuned, regardless of whether it is a gutless RGT or an overweight Dodge Challenger. Drifting ability has something to play in that, but I never find that the qualities or tune of my cars, even for slapped-together-in-online-lobbies tunes cause me trouble.
If you would like, give me a car and I'll run it through the program and show it to you. Provided it's a viable enough drift car, it should run fine (though still catered toward my taste in driving, as most of the ratios this program gives me are tied to what I was already comfortable with, or just augmented from that point)
The comparative tuning section of my formulas are designed to take a car you feel comfortable with, and make a second car drive as similar to that one. By focusing on the similarities between the physical properties of cars, I believe I have achieved that.
For Engine And Weight: I enter in weight, static weight distribution, Horsepower at peak, Torque at horsepower peak, torque at shifting point, torque 1K below shifting point, and torque 2K below shifting point. I may add 3K below if, after tuning, the car's shifts are very long. The formulas give me the static weight over each wheel, taking into account downforce. (an estimate since GT5 tuning does not give precise measurements of max downforce, I don't have a need to change this as I rarely used spoilers or wings) it also gives me a
For Suspension: Using spring rates, it tells me the drop on the suspension when the car is standing still, including the lowering height. With a Center of Mass measurement and tire G-force, it gives me the load transfer under ideal cornering. This tells me the "weight" over each wheel during cornering, including whether or not I have lifting forces on a particular wheel. It gives me the roll angle of the body during ideal cornering. Then, it takes into account acceleration and braking, and tells me all of that data again except this time it assumes first that I am turning while accelerating, and then turning while braking. It gives me a suggested camber value (though I usually go lower than this) based on the change of position of the Center of Mass under the previously mentioned scenarios, which changes the angle at which the force of weight is pushing on the wheel. I do not use toe, though if I wanted to add it to the sheet, I would have to start measuring wheel diameter and width so I know the exact contact patch, and then calculate the deformation of that to give me the idea rear width of tread from toe. While this is something I can do, I don't know if GT5's tire model is accurate enough to include real compression rates of the gases within the tires under the temperature of the tires under friction. Because it gives me the load transfer, I can select dampening rates in the same ratios as I want the load transfer to happen (as greater load transfer requires stiffer dampening to slow the change usually) and then move the rates higher or lower based on the track. For the most part, however, I keep them at a moderate level so I don't have to mess with them for every track. Same goes for anti-roll bars and the roll rate of the car. The sheet tells me if the front end rolls before the rear end does, and what the degree of angle is rolls is. It tells me the visual change in suspension drop on the outside of the car under cornering roll, at each wheel. It tells me the ratio of weight on the inside to the outside of the car under cornering, which I want to maximize to 1 to get the greatest cornering grip. Of course, no car has a 1:1 ratio, but the higher the number the better. It tells me how far the nose dips when I brake. All of these length of suspension travel measurements are important, because they tell me for a given spring rate set whether or not I am going to bottom out the car under normal cornering. All of these are kept in ratios similar to a car I am already capable with, and can be intensified if I want to speed the car up.
For Brake Balance: Using load transfer under braking (from previous section) I can calculate the lift forces employed at the wheels. This tells me the ratio of brake balance I need for all four wheels to lose traction simultaneously, and then I usually increase the front by 1 or 2 to compensate for cars where the front brakes are more powerful than the rear. While this is not an extremely precise measurement, all it does it make the front wheels lock first, which is all I want it to do, without having to do trial and error tests.
For Transmission Ratios: Using the ratios of the transmission I calculate the torque at the wheels for the torque values presented above (all of them) and the gear ratios. I try to get the ratio of weight over the rear wheels to the torque at full throttle the same, and the same under braking. To take into account the varying shapes of the torque curve for cars, I provide an average torque across the entire operating RPM spectrum based on the values I measured. This tells me that at the same throttle input at the same braking and at the same cornering, both cars (the original tune and the new car) will lose traction with the same force of sideways movement in proportion to the weight of the car. This dispels a huge misconception that horsepower determines the drifting character of the car, and while to some extent that is true, it rarely is useful. While the Fairlady Z has nearly 280 ft/lbs at the rear wheels, seemingly underpowered, it has, under braking, double-digit weight at the rear of the car. With the aggressive transmission ratios I use, it spins the tires at will from the driver, but is completely manageable in a straight line. It also lets me know which is more advantageous: a broader torque curve at lower peak numbers, or a higher one with a smaller breadth. It tells me whether or not I should have more torque at a lower RPM so that I can run gears at appropriate drifting speeds. I have to make the decision whether to do that, but the sheet tells me if that would be more similar to what I am used to, or less similar.
There are other things in it that I tune for, but these are the big 4 that I am concerned with, and the rest are usually stylistic measures to find cars that look more dramatic (higher rear/front ratio for a given angle of rotation, for example) that has little effect on performance. Does this give you a better idea of the depth of my tuning?
