I only made a few attempts at the 1/4 mile speeds. You might try some of my experimentation to a farther degree. Now during the run, generally time the gas pedel to go from mid RPM, RPM's increaseing to just below the redline when timer to 0.000. Each car has a different optimum launch RPM, and it is another factor that must be found. It can make a few 10th difference, but when you get the feel of it, you narrow it down to in the 100th.
Keep this in mind... What follows is not all certain, and if it conflicts with others, try that too, and please... let us know what works well.
1) Use Automatic Transmission for consistency in finding the optimum settings. Once the settings are determine, the manual shift must be used for best times.
2) set camber and toe to 0 as you are only going strait
3) Set the HP and Tires like you want, probably max power and R5. I wonder if R1 will help on the non-drive axle? If a car has max NA, max Turbo, and SC at HP values withing perhaps 5%, consider that max HP might not be best. Try the one with the strongest torque band as well if it is broader and/or stronger 20-25% below the top RPM.
4) You at lest need the 1-way axle. I think the best setup for the axle is Full Custon with acceleration setting to max (min? for earliest lock). I simply always used this setting without experimentation, so not certain.
5) Experiment with the suspension to your satifaction. I think you want to keep the springs/bound/rebound relatively loose, height mid range and rear higher than front. However, I did very little here. I believe the best stabilizer setting is max. It is possible that a sport suspension or semi race might be better than the full. In the real world, a drag suspension and race suspension are completely different in the physics behind their geometry. If the GT4 physics simulation is correct for height, it changes the front/rear weight transfer during acceleration and highest might be right for some cars. We are changing the center of gravity angle to the drive axle. Remember, we do not need to set low for cornering.
6) Do trial runs and find the right transmission setting. Normally, the full custom transmission with the spacing set to finish high RPM in 4th or 5th, however, the standard, sport, or semi race might end up being the optimim as well. Make at least 3 runs per setting and increase and decrease final and/or auto till you find your best point. Anytime you cross a point where you use and extra gear, or one less gear, you add or subtract a small time of acceleration. Keep this in mind as it may appear you are going the wrong way, but continuing may end up being better. At the moment, just get close and refine it later.
7) now, find the optimum TCS setting. I have found normally 7-8 gives the best times, but I was testing cars with at least 800HP. Unless when you drive, you can very accurately control the optimim RPM during tirespin, you will need this. Even if you can, Use this for consistency to find the other optimum setting. Make a few runs with various settings, and use the best.
8) Now, find out if Ballast over the drive axle helps. It doesn't immediately make sense that adding weight makes the car go quicker, but what is does is add traction over the drive wheels. This generally gives better times on light cars to about 100KG. 200KG is needed on the TVR Speed 12.... Make several runs. I am not certain, but I believe you want the weight over the rear axle of a 4WD as well. In the case of regular cars, it is likely best to do stage 3 weight reduction, then place weight over the rear axle. I don't consider FF cars 1/4 mile racers, but of course, place the ballast in the front for a FF if you are silly enough to use a FF.
9) Now, fine tune the values of steps 4-8. When setting the transmission again, it is often benificial to set 1st-3rd to lower numbers and 5th-6th to higher nimbers (might be 1-2 and 4-5 or 6 on other transmissions), making the transmission closer range than auto-1. If you do this, always use final to change ratio's once you find the spacing you like.
10) change your options to manual shift. Be consistent at launch RPM's and experiment with starting in 1'st, 2nd, or 3rd being best at launch, then shift RPMs too. Most cars have an optimum shift point either above or below the red line, and it varies also at each shift, i.e. 3-4th shift point optimum different than 4-5th shift point. Generally, the times will be substantially better now with starting in 2nd or 3rd gear and manual shifting. Now make changes as needed on the final drive ratios as needed. Often, you will hit the RPM limit and have to increase the final number a little at this point.
Good luck with all this. Hope it helps. It takes a long time to find the best settings. Once you find the best, I recomment taking TCS to 0 and try to find the best RPM for tirespin and acceleration. I have not done this on my attempts, but would if I was serious about 1/4 mile times.
A note on transmission tuning. If you want a full range during all races 1/4 mile or otherwise, and cloer range than auto-1, do the following:
1) Set final to about 3/4 of maximum and make not of the number. Should give a nice range for adjusting top speed on fastest tracks, and best acceleration for slow curvy tracks.
2) Set Auto to 1. If already on 1 or 2, move it away from 1, then to 1.
3) Set first gear and top gear to maximum
4) Set second gear to minimum
5) Set 3rd to 5th (if 6 gears) as needed for the mild curve normall seen, or flat shape.. Linear is geneally best if using automatic shift, expoential (curved) is generally better for manual shift. Note that with linear the best shift point will be the same at each gear and with linear, decreases as gears progress.
6) Never make auto changes from this point, only adjust Final Drive for optimum max speed for the track. Set final drive to lower numbers for high speed tracks and higher numbers for max optainable speed for short tracks with no room for attaining high speed. If full range not attainable for slowest to fastest track, then the 3/4 point in step 1 may need a starting point higher or lower. Use the test tracks for Top Speed and 400 meter to test if you have full range adjustment with the final.
) so I use the buttons.
