Do you want to get the most out of your vehicle’s automatic transmission? Are you looking for ways to make your driving experience more efficient and enjoyable? If so, then this blog post is for you! We’ll provide tips on how to improve shift point speed in an automatic transmission, so you can get the most out of every drive.
1. Understand How Transmission Shifting Works
Understanding how automatic transmission shifting works is the first step in improving shift point speed. When Driven Wheel Speed, Driveshaft Speed or Driveshaft RPM is used as the Shift Point Variable, just ensure that the down-shift points are below the opposite. To make the transmission shift smoother, adding a throttle response controller is the best way to do this. Optimal shift point is defined as the flywheel rpm for which the difference in transmission output torques between two gears is near zero for the same. Modern automatic transmissions will shift up at low rpm’s if the acceleration is on quite a light throttle, but if full throttle is being used, the transmission will downshift at higher rpm’s. Additionally, aged and low quality transmission fluid can also lead to poor shift quality. Therefore, it’s important to be mindful of how you accelerate; if you accelerate gently, shifts will occur at lower speeds than if you accelerate at full throttle. Manually downshifting an automatic transmission into a lower gear slows the vehicle with lower gear ratios reducing the output speed of the engine. If the car has quick acceleration and does not appear to shift, then it means that the shift point needs to be lowered by adjusting line pressure with a modulator pressure and raising the shift points with tables. Lastly, installing a throttle response controller can also help improve shift point speed.
2. Calculate Down-Shift RPM Points
Once you understand how transmission shifting works, the next step is to calculate down-shift RPM points. To do this, choose the target RPM you want to end up at when shifting into the new gear. It’s important to remember that there’s not much point in down-shifting below peak torque, so try to run the engine up to approximately 500 RPM above the peak torque before completing the shift. Using the data from the torque vs RPM graph and the relationship between RPM and speed for each gear, you can determine the torque curve for your engine and determine which gear will give you the fastest possible acceleration at your current speed.
3. Identify Optimal Shift Point
To identify the optimal shift point, you will need to look at the torque vs rpm graph, and the relationship between rpm and speed for each gear. Generally, you should shift gears up when the tachometer is around “3” or 3,000 RPMs; shift down when the tachometer is around “1” or 1,000 RPMs. However, this may vary depending on the type of car you have. After some calculations, it can be determined that shifting at redline in 1st gear is optimal. This is because the power made in 2nd gear at 4300rpm had been MORE than the 1st gear at redline. So for most cars, shifting at the ‘flashing blue’ or slightly thereafter will be the ideal shift point. Remember the higher gear will drop us down the rev ranges for the speed you are going.
4. Understand the Role of Line Pressure
It is important to understand the role of line pressure when attempting to adjust shift points in an automatic transmission. Line pressure is the pressure that the transmission fluid is under when the transmission is shifting. It is generated by the modulator valve and determines how quickly and smoothly the transmission shifts. If line pressure is too low, then shifting will be slow and clunky, while higher line pressure results in faster and smoother shifts. By understanding how line pressure works, it can help you adjust your shift points to get the optimal performance from your transmission.
5. Adjust Line Pressure With a Modulator Pressure
Once you have identified the optimal shift point, it is time to adjust the line pressure. This is done with a modulator pressure, which senses the engine torque and varies the shift points according to throttle opening. The cable on the 700R4 and 200-4R transmissions control line pressure, shift points, shift feel, part throttle downshifts, and detent (full throttle). To adjust the line pressure, simply turn the adjustment screw inward. Start by turning the screw in at least 5 full turns and then do a test drive. If you find that you are still not satisfied with the shift points, you can adjust the screw further. Another way to raise line pressure is to install Sonnax Line Pressure Booster Kits for 3/4 and 5/6 Speeds. These kits have large-ratio boost valve action for crisp, clean shifts without harshness.
6. Raise the Shift Points With Tables
Raising the shift points with tables is a great way to improve the shift point speed of your automatic transmission. In order to adjust the shift points, you need to adjust the speed in the shift tables. This can be done by using the “Increase” or “Decrease” buttons, as well as adjusting the vehicle speed and RPM in small intervals, less than usual. Additionally, when Driven Wheel Speed, Driveshaft Speed, or Driveshaft RPM is used as the Shift Point Variable, make sure that the down-shift points are below the opposite speed. Increasing the shift points at high throttle for tables like “Auto Upshift Group A – xx Gear” can also help improve shift point speed.
7. Use Least Throttle to Accelerate
When it comes to accelerating with an automatic transmission, the key is to use the least amount of throttle as possible. Gearing is give and take, so the more top speed you have in any given gear, the slower it will accelerate. This means that using too much throttle can cause the transmission to shift at a slower rate. To maximize acceleration, it’s best to use a light throttle and shift at the optimal points for your engine and gearing combination. With a manual transmission, you can shift into the upper gears quickly, allowing you to accelerate faster. However, if you’re using an automatic transmission, you’ll need to adjust the line pressure or install a throttle response controller to improve shift point speed.
8. Install a Throttle Response Controller
Adding a throttle response controller is one of the best ways to smooth out the shift point and make sure that your transmission shifts don’t jump. This device can drastically change the driving dynamics of your car, from acceleration to downshifting. Once you’ve installed it, you’ll feel like you’re driving a different vehicle! It’s a cost-effective way to improve your driving experience and get the most out of your car. The 8-speed GM transmission has often been criticized for its lack of throttle response and laggy shift points, but this controller will help to rectify that. You’ll notice an immediate improvement in shifting performance.
9. Check Transmission Fluid Level and Quality
It is important to check the transmission fluid level and quality of your vehicle regularly to ensure proper shifting and performance. The transmission fluid helps to cool and lubricate the mechanism and it should be checked for signs of evaporation or leakage, as well as for its frictional properties. If you have an automatic transmission, you can easily check the state of your transmission by checking the quality of the fluid, as aged transmission fluid can lead to poor shift quality. If you find that your vehicle’s computer is not providing the expected shift points, it’s best to check the oil level and diagnostic codes first. Additionally, you can also adjust line pressure with a modulator pressure or raise the shift points with tables in order to improve shift point speed in your automatic transmission.
10. Have a Professional Check the Transmission
It is always recommended to have a professional check the transmission for any underlying problems. They will be able to diagnose any issues that may be causing your shift points to be off, and can offer solutions for improving shift point performance. A professional may also be ab