atx performance


This page deals with how to modify your 31TH/A413 three speed automatic. This is the automatic used in 1995-2000 Dodge/Plymouth/Chrysler Neons as well as other cars, such as the Chrysler cloud cars. Starting in 2001 (a few 2000's), the Neons received the 41TE four speed automatic. We will not go very in depth with technical discussions here. If you wish to read up on anything touched upon here click over to Mookie's site or go back and read specific articles on our main tech page. Some Neon owners have certain reasons for not swapping in a five speed manual and sticking with their three speed automatics. While many will deem this a stupid and senseless choice, they are simply ignorant jackasses. For those of you who wish to keep your automatic transmission please read on and learn how to maximize what you have. There are three common modifications which you can perform to increase the performance of your automatic. They are a shift kit / performance valve body, *higher rpm torque converter* and *transfer gears. This first mod is good even if you don't intend on bringing your automatic to the track. You have two choices on what you can do for your valve body. A modded valve body will give you firmer, quicker shifts as well as raise the shift point. This will help keep you from losing power and also help you make more by winding out your motor a little more. If you are confident in your own skills and are a little adventurous you can perform the shift kit mod* yourself. Directions for this mod are found here. If you do not want to perform this modification you can purchase fully automatic performance valve bodies from places like Modern Performance and Howell Automotive. If your motor is going to be making power up where even a performance valve body will not let you rev, you can also purchase a manual reverse valve body. Unlike the performance valve bodies sold by MPx and Howell, a manual valve body essentially turns your automatic into a three speed clutchless manual. The car will not shift into the next gear until you shift it. It is called a "reverse" manual valve body because it changes the gear settings from P R N D 2 1 to P R N 1 2 3 so no one slams their car into N or R while at the track. A manual valve body would work best coupled with an aftermarket computer and a big cam (s). You can buy a reverse manual valve body from Turbo Action. It is listed as a Torqueflite 403 (part number 14166). After you install / modify your valve body, you may want to look into a higher rpm torque converter. A higher rpm torque converter lets you launch at a higher rpm, which allows you to leave the line with more power. The stock rpm torque converter is 2400 rpm. The most common converter is the Alabama Boss Hogg converter sold at Howell Automotive. Converters can also be purchased from Level10 and Forward Motion, however these will be more expensive then the Howell sold unit. However, the ABH unit is not meant for a daily driven car. Imagine driving around town while always slipping the clutch... With any torque converter you should also install a secondary transmission cooler since the extra slipping associated with this mod will create more heat - and heat will destroy a transmission. For a more technical look at torque converters I suggest you visit Mookie's automatic performance site or click over to my atx performance site, which includes Mookie's article on how a higher stall torque converter works.. The final mod for an automatic is to actually change the gearing itself. This is done most effectively through the use of transfer gears. By replacing the stock gears with those of a different ratio you can change the final drive of your transmission. The most common place to source the 1.22 transfer gears is from VW powered L body Chryslers. At one point in time Forward Motion sold the gears, but currently only sell the gears in their race transmissions. Be forewarned that the increase in final drive will decrease your fuel efficiency especially on the highway. If you want a cheaper way to adjust your gearing, you can run shorter tires on the front wheels. On the SOHC Monster the 195/60/13 tires were barely 20" tall which increased the car's final drive.

This page deals with how to modify your 31TH/A413 three speed automatic. This is the automatic used in 1995-2000 Dodge/Plymouth/Chrysler Neons as well as other cars, such as the Chrysler cloud cars. Starting in 2001 (a few 2000's), the Neons received the 41TE four speed automatic. We will not go very in depth with technical discussions here. If you wish to read up on anything touched upon here click over to Mookie's site or go back and read specific articles on our main tech page.

Some Neon owners have certain reasons for not swapping in a five speed manual and sticking with their three speed automatics. While many will deem this a stupid and senseless choice, they are simply ignorant jackasses. For those of you who wish to keep your automatic transmission please read on and learn how to maximize what you have.

There are three common modifications which you can perform to increase the performance of your automatic. They are a shift kit / performance valve body, higher rpm torque converter and transfer gears.

This first mod is good even if you don't intend on bringing your automatic to the track. You have two choices on what you can do for your valve body. A modded valve body will give you firmer, quicker shifts as well as raise the shift point. This will help keep you from losing power and also help you make more by winding out your motor a little more. If you are confident in your own skills and are a little adventurous you can perform the shift kit mod yourself. Directions for this mod are found here. If you do not want to perform this modification you can purchase fully automatic performance valve bodies from places like Modern Performance and Howell Automotive. If your motor is going to be making power up where even a performance valve body will not let you rev, you can also purchase a manual reverse valve body. Unlike the performance valve bodies sold by MPx and Howell, a manual valve body essentially turns your automatic into a three speed clutchless manual. The car will not shift into the next gear until you shift it. It is called a "reverse" manual valve body because it changes the gear settings from P R N D 2 1 to P R N 1 2 3 so no one slams their car into N or R while at the track. A manual valve body would work best coupled with an aftermarket computer and a big cam (s). You can buy a reverse manual valve body from Turbo Action. It is listed as a Torqueflite 403 (part number 14166).

After you install / modify your valve body, you may want to look into a higher rpm torque converter. A higher rpm torque converter lets you launch at a higher rpm, which allows you to leave the line with more power. The stock rpm torque converter is 2400 rpm. The most common converter is the Alabama Boss Hogg converter sold at Howell Automotive. Converters can also be purchased from Level10 and Forward Motion, however these will be more expensive then the Howell sold unit. However, the ABH unit is not meant for a daily driven car. Imagine driving around town while always slipping the clutch... With any torque converter you should also install a secondary transmission cooler since the extra slipping associated with this mod will create more heat - and heat will destroy a transmission. For a more technical look at torque converters I suggest you visit Mookie's automatic performance site or click over to my atx performance site, which includes Mookie's article on how a higher stall torque converter works..

The final mod for an automatic is to actually change the gearing itself. This is done most effectively through the use of transfer gears. By replacing the stock gears with those of a different ratio you can change the final drive of your transmission. The most common place to source the 1.22 transfer gears is from VW powered L body Chryslers. At one point in time Forward Motion sold the gears, but currently only sell the gears in their race transmissions. Be forewarned that the increase in final drive will decrease your fuel efficiency especially on the highway. If you want a cheaper way to adjust your gearing, you can run shorter tires on the front wheels. On the SOHC Monster the 195/60/13 tires were barely 20" tall which increased the car's final drive.