Of course it all depends on many factors (how well the truck rolls, surface conditions, gearing and temps), but with my 5150 in my SCTE (I would think a similar drive-train efficiency), I am averaging around 500mah a minute. Figure the 4500 uses a little less power hungry, so I would say 450mah a minute, so roughly 10 minutes.

Of course this is a "best guess". Too many variables factor into it.

The PWM frequency is a setting that allows the user to adjust the static efficiency of the speed control. Think about the length of the winding in a 17.5 motor vs. that of a 4.5 motor. The 17.5 has roughly 350% more length of wire inside it per winding. So the optimum frequency for any particular motor configuration (Winding, 2-Pole vs 4-pole, Sensored, Sensoreless, wire size, rotor diameter, etc...) will change.

On most ESC's, this is a fixed setting, and in the past there have always been certain ESC's that were better in stock vs some better in modified, and the most common factor has been the frequency of the ESC.

Typically, a lower setting will net you cooler temps (because the ESC is working less), but will net a softer feeling motor. Not slower, just less "oomph" . Higher settings will make the ESC run hotter (slightly), but will give the car more drive off the corner, more linear feeling.

Just about the best way to tune the setting is to start low, and keep going up until you stop feeling a difference. It isn't a major difference, but you can feel it. Once you stop seeing a difference, go back one setting (if you went from 9600, to 12000 and it didn't feel any better, go back to 9600). In general, higher turn motors (17.5, 20.5 and 22.5) will be optimized at lower numbers (4000hz) where as lower turn motors like a 4.5 turn, you can get significant changes all the way up to 16,000hz.

Unfortunately in your application with a 17.5 motor, the PWM Frequency makes less of a difference in the slower motors, so there is probably not allot to be gained, usually 4000 or 6400 is about the best settings.

All of the above is most applicable in the 540 motor applications. With the 550L and 550XL motors, Viper recommends setting the PWM Drive Freq to 12,000hz and above.

That sounds exactly like what happened to mine back on page 295...


Another race weekend and I think I've found the problem. It's either using inferior batteries, or (maybe a combo of both) the CopperheadR has a weird LVC. It happened multiple times to me this weekend (in addition to last weekend). Every time it cut off, I was using Gens Ace 4800mah 25c saddle packs. Obviously not the best for a high current app. like the 5150/CoppR, but cheap saddles for the Durango are far and few between.

Anyway it happened again, running a few minutes, then shutdown. I switched motors to my old Tenshock (4600kV), and it shutdown for the third time. This time, it was accompanied by power loss. Eventually to the point full throttle got the truck to just creep forward. I then switched to my Pro Match 5200mah 60c saddles, and boom, no more problems. Ran the truck, charged the saddles, ran again, no problems, charged, ran again, no problems.

So maybe the LVC in the Copperhead has a longer delayed, or hard cutoff than most are used to? I think additionally, lesser packs may be dropping voltage too far, sending the Copperhead into LVC. That why at like 2 minutes into a heat/main, the car shuts off. A current spike sent the Copperhead into LVC.

Does this sounds of reasonable logic to any of the Viper guys? Is the LVC different then other ESC's out there? I am running my CopperheadR straight out the box, no changes. My previous setup was an RX8 with the Tenshock, current limit set a 60%. Maybe that would explain how I was able to manage with the crappy Gens Aces, where the CopperheadR just kills them?

Some profiles have a different lvc setting if memory serves.

There are NiMH and LiPO voltage cutoffs on the Copperhead. The NiMH cutoff is lower and could actually hurt your lipo if you were in that setting. When it cuts off - are you getting any error lights on the switch? It is possible that an older - poorer performance battery would not be able to keep the properly voltage - if the esc detects that the voltage has dropped too much, it will shut off. That is instability in the battery more than the esc.

I had a Venom do just that. Would run great for 3-4mins and then bog around. Charged correctly according to cell voltage, but after 3-4mins a cell would drop out.

I'm not so much referring to the very point at which LVC protection kicks in, but how LVC protection actually works. Is it really as simple as the very moment voltage reaches cutoff (say 3.2v/cell) the esc turns off power to the motor, and then out to the very 0.01v that the batteries go above LVC, the esc turns back on? Or is the LVC protection more like a program. Where once voltage hits a certain number, say 3.20/cell, it then waits till voltage goes back up to say 3.4/cell before it comes out of LVC?

When I used to hit LVC with the Tekin RX8/Tenshock combo, after 5-10 seconds, the truck would fire back up and I could drive a little bit before it went back into LVC. With the very same batteries with the CopperheadR combo, once I hit LVC, the truck is flat dead in the water. After at least 45 seconds, it still hasn't come out of LVC.

The LVC is pretty strait forward. Once it is below the voltage it will just shut down. Easy way to test is to drop from 3.2v to 3.1v without recharging and see how it performs.

17.5 blinky
 

I have a question, what are the thoughts on endbell timing and pinion gearing for the viper 17.5 in blinky. I have been running my timing all the way up and geared about 76/28 on a tight carpet offroad track. I know our motor is only 1900kv and the Revtechs are 3,000kv, but they can run 75/25 on same track. Should I turn the timing back down to 20 and then gear up to a 30 pinion. What is everyones opinion on this. gear up or timing up???

Have you tried gearing down and timing up?

Revtech is 2300kv in their orange / blue 17.5

Actually they changed the Spec, but I am wondering if it is 3000kv. It was 2300 in the 2011 RevTech Catalog

Allot of variables that go into it. 17.5 is so on edge you can be ok one round, and if they water the track you will cook it (grip went up, loaded motor more)

The VST is low on kv, BUT is very high on Watts (Torque), this formula tends to let you run more gear (I have run as high as 38/70 on a TLR 22 - Which is geared higher internally than a B4), but I was down in the 15-20 deg range of timing. You have to test and experiment.

what copper head system is good for sc10 4x4? ill be running a medium to large sized indoor track, some outdoor 8 scale tracks and some small and tight tracks....

I care about control and feel. I hear this system is very smooth..any opinions!?:D:)

R45 would be my choice

Guy the 45R is good for Island. That is what Royce has been running there.