cheers
looks like i may have to check the diff.

So what I am getting from what your saying is to keep this motor running at any kind of speed I need to spend $30 every two times I run it? I for the life of me can't get the VST 17.5 to keep up with my D3. The Trinity has 5 times the runs on it and has loss no power. I have sent my VST back in to Viper and they said it was fine. I don't think having to change out rotors as your stating is "fine".


Fustrated.........

Well RcTech is not the Viper warranty dept, they have had their eyes on it and they are better off to judge the motor based on being able to see it. And if the problem does not come from the way it was made or the failure of the material, there is not much they can do with it.

A D3 motor is about 2100kv, where as the VST17.5 is only about 1900kv. It does not make as much RPM per Volt, so that means at a nominal voltage of 8V, the VST is going to be down 1600RPM vs. the D3. To get the same amount of speed, you are going to have to be geared approximately 10% higher to achieve the same amount of strait line speed. If it is fast on the strait, but not allot of punch, you will have to gear down and go up in timing.

The comment about changing rotors every 2 runs was to inform you of the nature of today's stock racing scenario. This is how Stock racing is, and in the nature of "Blinky" racing, the one who is willing to live on the edge of killing their motor will be the one most likely to win. It's always been that way in Spec/Stock racing. Its a combination of knowledge and the "motor of the week" game that is necessary to stay competitive.

On-Road racers are paying extra to some motor builders to have them go thru their rotors and "hand pick" the ones with the best magnet numbers.

Looking for some input, had a rough race weekend with new copperheadR/5150 in my Durango.... I had very little time to setup the truck. Ran the truck around my house, lots, and lots of power. But god is the motor loud. I've seen in this thread a couple comments about the noise, so I'm not too concern. But geez, at a very certain rpm the squeal is very unnatural. I also think the plastic rear cap has a lot to do with this....

Prerace practice, the center diff blew. Swapped out to the original locker, press on. Qual. 1, she cut off on lap 4. I still had steering, but no motor. I had a 15t pinion in there (54t spur). We race on a large'ish loose outdoor track. The turn marshal who pulled my truck off said it smelled hot. Didn't have a temp gun with me, by the time I got back to the pits, the esc/motor wasn't much above ambient (75-80°F).

Before Qual. 2 I swapped down to a 13t pinion. On lap 3 this time, after a light tumble, I lost motor power again, still had steering. Instead of going to the truck, I just let it sit parked off track, and after 2-3mins, it worked again and I was able to get another lap in.

Practice before the mains, I ran a pack thru the truck flawlessly, motor/esc were both 110°F at cutoff. In the B-main I gapped the field on the first lap, and then nursed the truck for the bump spot. I only used 1800mah for a 6-minute race!!!! In the A-main, the truck was flying, fastest lap ever at the track for a non-1/8th... Truck lost a rear center cvd pin on the final lap and came home 2nd.


What I think happened, in Qual 1, it probably did get into thermal with the monster pinion I was running. In Qual 2, I really wonder if the button on the multi-switch got knocked into that blinking mode when you press the switch once? Has that ever happened to anyone before?? I have the switch mounted flat on the chassis, could that be it? I'll mount it on its side I guess.... Just so weird how I couldn't get 4 laps in the Qual's, but truck did great in the mains...

In qual 2, after your tumble and you lost power, did you just try it once and then let it sit the 2 min?

Copperhead, like most sensor-less systems, will delay slightly if the ESC can sense the motor moving, but cannot tell which direction it is moving. It is set-up this way to keep from hurting the electronics. But the delay is very, very brief. Like 1/2 a second.

Copperhead R.51 can pull a TREMENDOUS, amount of gearing, and not really get the motor all that hot. I have yet to see anyone get a temp any higher than 120 or so on the motors. But, the ESC will get warm and shut down to protect itself.

If you have a ProGauge turn the timing to 1, and turn the punch down to 1 or 2. And also turn the brakes down to what is practical. In brushless ESC's, running allot of brake will make allot of heat in the ESC.

I run a R.51 in my SCTE, and with a 14T pinion on a medium sized / open layout, If I run any more punch than 2, and timing more than 1, I can get the system to "stall" briefly if driving hard. Switching to a 13T the truck was not any slower anywhere on the track, was easier to clear jumps with and I could drive it as hard as I wanted.

Copperhead has so much torque that it can be deceiving on gearing. It will pull a very big pinion and not feel very lugged down. But once you get it in the "sweet-spot" you will know.

last night i threw down the 10.5 in my car, geared 25 75(hobby wing xerun)-waiting for my viper to come.

my throttle was full about 3/4 throttle I did not play with many settings except for brake and the throttle frequency, i even rebound my stuff a few times. I ended up throwing my epa down to 85% to use it.

i set the speedo to stock setting for off road no boost profile, messed with break and changed frequency to 6400,

You are saying that you would get a solid light when the trigger was at 85% throttle?

Do you know what version software you have in the ESC? (A19, A30, etc.....)

idk about the lights but between half and 3/4 throttle was the top end, anymore i pushed was no different.

i guess you can say the power band was 75% to work with, 3.4 was full, after that didn't change.

if the box doesn't say a30, then its a19? then i have a19 lol

If you have tried to re-calibrate it already, what you can do is dial back the EPA on your radio so that you get full throttle at full trigger. The "F" light on the switch will go solid when the ESC is wide open. Just keep turning the EPA down until the light goes from Solid to Blinking, then just go back up a few clicks to keep it solid.

Also check the brake and set it the same way.

As far as software version, the only way to tell what is in the VTX is to plug in a ProGauge

Guy, make sure your EPA's are set at 100% before you re-bind your esc to your radio. Also check and see where your Throttle Curve is - I know in one of your past set ups you used EXP+ - which ups the curve to reach top end faster.

What Motor and ESC would you recomend for the XXX-SCT for racing both off-road and Late-Model SCT??? I run in a Mod Class in both Right now with a Novak Ballistic 8.5!

The VTX10R will give you the flexibility to go even lower in motor choice if you want. But the VTX10 will cover down to 6.5.

If you have been using a 8.5 successfully, stay with that wind. Want to try a little more - go to a 7.5. That really depends on your driving style and what you feel you need on the track. I have seen people race 7.5 to 10.5 and end up with the same lap times - it all depends on how you drive and how your car/track can handle it.

The little red rubber button popped off my VTX10R switch! It's lost. Can I replace? What can be done?

You would have to send it to Viper.

That ain't good.