ST550 Recommended Upgrades

Out of the box, the Team Associated Apex2 Sport ST550 is a fun car to drive. There are a few upgrades that can be added, though, to help boost the performance of this TC, especially if you’re going to enter the Super Touring Championship.

Let’s take a look at some of the upgrades we suggest to bring your car up to race-ready Spec.

Gearing

The first thing that needs to be addressed is the gearing. Since the SC500X ESC is 3S capable, AE has released the car with a conservative gear ratio based on that fact. If you use a 2S pack, you’re not going to get much speed out of it. It is suggested that you replace the stock pinion with one to match your track size, maybe a 25 or 26 to start.

See our video here of how to change out the gearing: (Coming Soon)

Bearings

The ST550 is shipped with a full set of Oilite bushings (except for the two bearings that support the center differential). To gain some extra speed (and help prevent the bushings from overheating and melting plastic parts), we suggest a full set of either Team Associated or Fast Eddy Bearings. At the moment, AE doesn’t sell a full bearing kit, so you’ll have to order them individually. Fast Eddy, on the other hand, does sell a full kit.

Fast Eddy Bearings
TFE8251 Apex2 Sealed Bearing Kit

Servo

The stock servo that comes in the ST550 is a Reedy 1523MG Digital servo. It has some decent numbers but it’s not been known to be the most reliable unit under heavy loads. Because of that, we are allowing drivers to replace the servo for the STC. You can use any standard or low-profile servo as a replacement, however we suggest either of these for the specs, reliability and price.

• Hitec HS-5585MH Metal Gear High Torque Standard Servo
• Hitec DB777WP High Voltage Low-Profile Servo

See our video here of how to change out the servo: (Coming Soon)

Differential Fluids

The front and rear diffs in the ST550 come with a bit of grease in them. It works fine but, for better performance, you’ll definitely want to swap that out for some actual diff fluids. The good thing is that the fluids are inexpensive and the diffs are sealed so it’s just a matter of what fluids to buy.

On a side note, the center diff comes with a locker in it – we are requiring that locker to stay in place for the first Season.

Shocks

The RTR comes with friction shocks which actually work quite well. The downside is they’re not tunable (other than the springs), so at some point you’ll want to invest in a set of oil-filled units. To help control cost (and equalize performance), we are allowing the upgrade to AE’s Apex2 oil-filled threaded shocks. There’s not a full shock kit available yet so you’ll have to piece them out, but we’ve listed the parts below.

#21557 Factory Team 10mm Front Spring Set (2 required for front/rear)
#31510 M2x4mm BHCS
#31864 Apex2 Shock Components
#31865 Apex2 Shock Rebuild Kit
#31866 Apex2 Shock Bodies, Plastic, Threaded
#31874 Apex2 Shock Shafts
#91820 Apex2 Ball Ends

The full set of shocks (including springs) will run you about $78. While some might think this is a bit spendy, a pair of aluminum shocks might cost you around $40 without springs, so about $110 and up depending on the springs you buy. We feel this is a good compromise between performance and price.

See our video here of how to change out the servo: (Coming Soon)

Reedy Program Card

The RTR ESC is a good unit to start off the Series with. It is a basic, lightweight ESC with some adjustability programmed in, accessed with the use of the Reedy Program Card. This card will allow you to adjust the following:
• Initial Drive
• Low-Voltage Cutoff
• Drag Brake
• Max Reverse Power
• Punch Control

Some of these will help to boost performance slightly. We should have a few cards on hand to help tweak your settings if you don’t have one at the event.

See our video here of how to change out the servo: (Coming Soon)

None of these upgrades are required to enter the STC – Ken Gerberding and I have been running these cars for a bit now and been busting out some good laps, but we definitely think the car has much more performance with the addition of at least the bearings, shocks and diff fluids.

If you have any questions, please feel free to reach out to us and we’ll be sure to help you out!