Just joined the site New to the RC World. Just bought my first car HPI RS4 3EVO anyways just bought the Futaba 3PM-X 3-Channel 2.4GHz FASST with the Futaba R603FF Receiver. Anyways I also bought two Futaba S3152 servos and after reading Tower Hobbies description I am afraid that the servos are to much for my stock HPI, I wanted the S3151 but they did not have them. Do you think I will be ok

s93152
Speed: .18 sec/60° @ 6V
Torque: 87 oz-in @ 6V
Weight: 1.5oz (41g)
Dimensions: 1.6 x 0.8 x 1.5" (40 x 20 x 38m)

s93151
Speed: 0.17 sec/60° @ 6V
Torque: 54 oz-in @ 6V
Dimensions: 1.6 x 0.8 x 1.4 in (41 x 20 x 36mm)
Weight: 1.5oz (42g)

heres the spec on both s9352 and s9351,
i think your ok! just check the difference on the speed and the torque on 6v.

I actually have the S3152 and the specs seem fine the part that actually has me thinking is this
From Towet Hobbies
"S3152 Digital Servo Precautions,
-It is best to avoid long leads and Y-harnesses especially with
standard grade wires. If problems are encountered, consider using
heavy duty wire such as Futaba's Heavy Duty Series or Hobbico's
Pro Series, minimizing lead lengths, and/or removing Y-harnesses.
-Current Drain: Futaba S3152 Servo is Specially Designed for High-
Torque and High-Speed, Therefore Very High Current Drain Is Normal
At Startup. For Ultimate Performance When Using This Servo
Please Review The Following Points.
(1) When Using Systems With the Battery Fail Safe Function it Has
a Higher Cut-Off Voltage Setting Which Will Cause Shorter
Operation Time.
(2) When Installing the Servo Please Check Pushrod Linkage To Make
Sure There Is No Binding in Order To Prevent Excessive Power
Consumption and Decrease the Life of the Motor and Battery.

there is nothing to worry about. as long as your wires are intact and good (no cuts) you are fine and everytime your going to start running your car use fresh batteries or fully charge your rx batteries. check also your servo horns, make sure they are at rest without binding or motor sound from the servo and your good to go.