Tuning Cars

Car tuning thoroughly is a black art. It requires a great deal of patience, time, and a heightened sense of observance.

Basic info:

Engine Speed Limiter (ESL) is basically a governor. Enables you to rev higher than the limits of the manufacturers suggested red line.

The benefit is reaping more torque for a longer duration. The risk is blowing your motor and forfeiting the race.

Final Drive ratio (FD) is an overall adjustment effecting all gears at once. In addition it's a power transfer from low end to top end, and vice versa. The lower the FD number the more power is transfered to your high end gears and the less power to your low end gears. Then too, the higher the FD the more low end torque and less high end tourque.

Individual gear ratios perform the same function as the FD, but only for that specific gear. I find it easiest to understand looking at it as a gear duration adjustment. The lower the duration the more power the gear has and vice versa. So the question becomes; will the car perform faster with more power for a shorter duration or less power with a longer duration.

It's all about finding that happy medium and getting the car to produce it's fastest time for track length you are tuning for.

NOS blueprint configurations play a part too. For the shorter tracks you want more power vs duration and more duration vs power for the longer tracks. Another post will explain NOS blueprint configurations.

Forget the Dyno graph exists and use the gear graph.

Cars under 700 cogs aren't worth the effort to do a thorough tune. Mainly because gear ratios don't remain static for the history of the car. Adjustments will always be required until there are no longer upgrades to put in it. In other words tune it today, tomorrow add a couple upgrades and now it needs a new tune.

Simply experiment with the ESL, FD, and driving task RPMs. Once you reach a plateau in finding upgrades for it, usually around 850 cogs, then worry about thorough tuning.

Tuning your car:

Beginning with the factory tune, test run the car using the green zone on the TAC as your baseline for both launching and shifting.

Observations:
Evaluate wheel spin - simply note it, without worrying about corrections at this point.

Evaluate the actual MPH when shifting and crossing the finish line. Note these MPHs.

Note the finishing time.

Adjusting the ESL:
Personally I have a maxed out ESL on all my cars except those that have challenging wheelie concerns that can't be corrected with FD and individual gear ratio tuning and launching at too low of an RPM. A classic example is the Dodge Dart.

Running a maxed out ESL requires an advanced launch technique as to not blow your motor before the race even starts. Finger tap launching and Full throttle launching and the drop back method become obsolete with an adjusted ESL.

All the tune vids I post demonstrate the best launching technique for cars with a maxed or more than slightly adjusted ESL.

Find the best ESL location for your current launching skill.

Final Drive adjustments:
While observing and taking note of everything previously mentioned begin experimenting with your final drive ratio at .02 increments in both directions until you find the FD location that produces your fastest time. It will be necessary at some point to decrease the .02 increment to dial in the best FD location.

At this point note your speed at the finish line and judge the amount of duration was left with the final gear used at the finish line. Then compare your actual MPH with the MPH displayed on the gear graph. There will be a variance. Note that variance.

For example: If you ran 5 gears on a half mile track finishing the race at 200 MPH and then compared where 5th gears duration ended in MPH, you'll more than likely see around 240 MPH on the gear graph.

So for however many gears you tune with the last gear in your tune should end it's duration at 240 MPH according to the gear graph.

Now begin experimenting with a different amount of gears. You'll need a starting point. I usually begin with 80 MPH being the end of 1st gear according to the gear graph. Slide the 1st gear knob until the line that represents 1st gear reaches 80 MPH where the line meets the redline. Using the example above; subtract 1st gears MPH duration from the race finishing 240 MPH according to the gear graph = 160 remaining MPH to distribute for the rest of the gears on your tune. So if you were using 5 gears, 1st gear took 80 MPH of your 240 = 160 remaining and the other 4 gears divided into the 160 = 40 MPH per gear. Then slide 2nd gear to 80 + 40 = 120 MPH. Then slide 3rd gear to 120 + 40 = 160 MPH. Then slide 4th gear to 200 MPH. Then slide 5th to 240 and test run the car.

Try a 3 gear tune, then 4, then 5, etc. until you find the correct amount of gears to use. Keep in mind to evenly distribute gears 2 through however many you are using at the time.

Once you've determined the correct amount of gears to tune. You can now experiment with finding your proper 1st gear ratio by using the math just described and set your 1st gear to 60 MPH and evenly distributing the rest. Then set 1st to 50 or 70 or wherever until you find your best 1st gear ratio.

Once you have found your best 1st gear ratio and have the remaining gears evenly distributed you can now begin finding your best launch RPM.

Launch with several different launch RPMs until you find your best launch.

Once you've found your best launch you can now begin gaping gears 2 through however many you are using.

This is where observance comes into play.
While taking note of everything previously mentioned, hopefully you will have noticed certain gears accelerating better than others. If you made no notice of this, perhaps even distribution is the way to go. If you have noticed other gears performing better, then you'll want to lengthen their duration a few MPH at a time and shorten the duration of the weaker gears a few MPH at a time until you produce your best time.

Use your preset B's for work in progress tunes and your preset A's for completed tunes.

Screenshot the shiftpoints graph with your best runs which helps you remember which cars require which driving task RPMs.

NOS push RPM is next & last. Simply experiment NOSing at different times to find the best time to NOS push.