Originally Posted by FLHX1550 (Post 10768827)

Well if the only problem is that it is hot, I would say that you probably should gear down to a 14t or 13t pinion, 15t is fairly high gearing for that truck with that motor.

Doing the math calculating for 8.0v with a 4.15" tire you are right at the same over-all mph of 42.5mph, which unless you have a real long strait is kind of high. You are more than likely lugging the motor so much it will not perform 100%.

FYI - comparing the R.45 to the R.51 motors, when in the Losi SCTE, the gearing works out that you need to be 2T apart to achieve the same speed.

R.45 Gearing / 40T Spur / 8.0v / 4.15 Tires
15T = 42.8mph
14T = 39.9mph
13T = 37.1mph
12T = 34.3mph

R.51 Gearing / 40T Spur / 8.0v / 4.15 Tires
15T = 49.0mph (NOT RECOMENDED)
14T = 45.8mph
13T = 42.5mph
12T = 39.2mph
11T = 35.9mph

These trucks are VERY power hungry. They are heavy, 4wd, and have a giant parachute strapped to their back. That and combined with a 2s battery limit for the class, it ends up putting a tremendous demand on the ESC and motor.

In testing, Viper has recorded peak amp draws of 160A and higher! It is very taxing on the system, so we recommend some testing and research before someone just goes out on the track.

I recently raced at a event that had some pretty nasty track conditions (track was dry / dusty / loamy for qualifying and it started to rain - the mains ended up VERY muddy) and saw ESC problems from all the manufacturers that were represented there. The biggest reason why? The people with failures were not compensating for the track conditions. They were not changing gearing / tires, etc..... for the build up of mud and dirt in the cars and tires. I myself finshed 2nd, with no ESC issues, but I ran BarCode tires in the mud so that they would not build up, and I turned the punch / timing down for the extra load.

With power demands being so high (in comparison, one can dump a 6000mah battery in as short as 9 minutes in 4x4 SCT, you can run almost 40 minutes in a 2wd buggy with that much mah), all factors have to go into gearing / setting selection to get the most out of the system.

Originally Posted by Scottmisfits (Post 10768996)

Vtx10r and vst5.0l ESC settings starting point for an SC104x4? Am running the latest firmware that I received from Erik last week. I know there was a starting point that was recommended before but I have lost that and don't want to burn everything up.

Thanks