Man, being tied to 3S really sucks.

I have trouble even running 12S!

Matt

Well its to have a large turnout. Most people can afford the 10 cell and 3S batteries. Also makes you have to tune the truck and know what your doing instead of just having the guy with the biggest wallet go buy twin Neu 1527's with twin 10S Lipo's....lol.

I understand. But, it can get even more expensive when you limit the power system because now you have to get a high cost very high amp ESC and a crazy high KV to achieve decent speeds.

Speed is expensive, no matter how you try to limit it.

What is that saying? "Speed costs money, how fast do you want to go?"

Matt

what about dual 6xls?

don't know that i can add anything here except if you're using rubber tires, run with some truggy tires, they seem to hold up to high speeds better. other than that, i did what mod man said, put as much power to the ground as possible. make sure the drivetrain can take it, although if your gearing high, you might get away with the lack of torque. using such low voltage pushing a large vehical fast, you better concentrat on an esc with very high amperage capabilities. your going to want as many watts as you can get and being stuck on 11.1v means really high amps. basically twice the amps that i'm seeing in my mgm160 since i'm using 6sa123's. make sure you get some batteries with a very high discharge, you don't want to over drawl them and loose motor speed from voltage drops.

here is a cheap 200amp esc to try out if you can find one instock anywhere.
http://www.himodel.com/electric/HiMo...200A-OPTO.html

make sure you get some flightpowers!

So which motor setup and ESC do you suggest. The the dual 7L's with dual mamba's a good choice or something better out there???

Won't the VXL3 from my Velineons support 200A cont. and 320A burst. I could always buy those again and the 7L's. But later I would like to go even faster with 4 or 5S but the VXL3's are limited to a retarded 3S.

if u got the cash, get a savage with dual 6xls, dual 3s 30c fp's and the 3 speed. or dual plett maxximums?

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1.5833333333333332
Other Ratio: 0.967741935483871
Spur Tooth Count: 51
Pinion Tooth Count: 24
Total Voltage: 12.6
Motor KV: 3100
Tire Diameter (inches): 5.7
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 2.13 : 1
Total Ratio: 10.77001 : 1
Tire Circumference (inches): 17.91 inches (454.84mm)
Total Motor Speed: 39060 RPM
Vehicle Speed: 61.5 MPH (98.79km/h)
Effective Speed Rate: 4.88mph/V (7.84kmh/V)
Effective KV Value: 3100
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...

thats with the maxximum if your wondering.

Which ESC's though??

I already have a stock 3906 waiting for the upgrades.

mamba maxes maybe or quark 125's or mgm....

Why not read my post on page 3?? Dual MM 57 or 6900's or perhaps 1509s....

yea, i think the mambas would b good but my post of the 69's was shunned.

Quark = no, too prone to overheating and requires extensive modification to run cool.
MGMs = safe bet, reliable, and plenty of high amperage models to choose from.
MMs = maybe, but they really cant take a massive amp draw for long periods.

The V-twin idea is simplest since you already have the escs, but you have to concider that the motors only have very short magnets inside that long can, so they should ideally be replaced with a similar Kv feigao motor, the 7L is 3500 isnt it?

As for the stock truck, once its beefed up to 3.3specs then you can have a bit of fun with it- I assume this race series is an ongoing thing and not just a one-off event. It seems like the VXL escs have the best continuous amp rating of most escs currently available for cars, and they are well priced for their specs. You could experiment with different motors until you find something that pushes the esc and batts to their limits... a couple neu 1509 1ys (3600kv) would be interesting on 3s, and they could be geared higher than the feigaos without overheating as much- then you will find the true limits of the VXL escs.

How about 2 1515 1D's?? Looking at them on Brian's calculator they seem to make great amount of power on 11.1's.

According to the calculator as well the Feigao 6L's seem to be spot on with 11.1v's, but I thought the rpm limit on the 6L's was higher then 40K? I just compared it to the 1515 1D and they seem to be about identical, or am I missing something. Also the price is more then twice for each motor....wow.

Two 5700s will will do it. If one 5700 is enough to push a 5bl truck to 65 mph, two 5700s will be able to push a 10lb to the same speed even easier since there is less than twice the wind resistance. The velineon motor btw is closer to a cm4600 motor, so that is not an alternative.

I recommend that you DO NOT get 6xls or 7ls or you will need twice as much batteries. Batteries supply the power. NOT the motor. Also you want to limit the rotational mass as much as possible.

Also, when you decide on batteries, try to get the biggest cells you can without having to put them in parallel. For example, two 3s1p 5000 mah packs would work better than two 3s2p 6000 mah packs.

Here is the spec sheet... for the MM5700's of course 2 of them....

Differential Ratio: 2.8461538461538462
Transmission Ratio: 1.83
Other Ratio: 1
Spur Tooth Count: 62
Pinion Tooth Count: 22
Total Voltage: 11.1
Motor KV: 5700
Tire Diameter (inches): 6.7
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 2.82 : 1
Total Ratio: 14.67839 : 1
Tire Circumference (inches): 21.05 inches (534.64mm)
Total Motor Speed: 63270 RPM
Vehicle Speed: 85.92 MPH (138.01km/h)
Effective Speed Rate: 7.74mph/V (12.43kmh/V)
Effective KV Value: 5700
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...





Although I highly doubt that 85mph will be done with only 2-11.1V's....lol.


Here is the 6L's.....

Differential Ratio: 2.8461538461538462
Transmission Ratio: 1.83
Other Ratio: 1
Spur Tooth Count: 62
Pinion Tooth Count: 22
Total Voltage: 11.1
Motor KV: 4096
Tire Diameter (inches): 6.7
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0.0043
Spur/Pinion Ratio: 2.82 : 1
Total Ratio: 14.67839 : 1
Tire Circumference (inches): 21.05 inches (534.64mm)
Total Motor Speed: 45465.6 RPM
Vehicle Speed: 61.74 MPH (99.18km/h)
Effective Speed Rate: 5.56mph/V (8.93kmh/V)
Effective KV Value: 4096
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...



And lastly the 1515 1D's, which are $$$$.

Differential Ratio: 2.8461538461538462
Transmission Ratio: 1.83
Other Ratio: 1
Spur Tooth Count: 62
Pinion Tooth Count: 22
Total Voltage: 11.1
Motor KV: 4100
Tire Diameter (inches): 6.7
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0.0025
Spur/Pinion Ratio: 2.82 : 1
Total Ratio: 14.67839 : 1
Tire Circumference (inches): 21.05 inches (534.64mm)
Total Motor Speed: 45510 RPM
Vehicle Speed: 61.8 MPH (99.27km/h)
Effective Speed Rate: 5.57mph/V (8.94kmh/V)
Effective KV Value: 4100
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...

Keep in mind that the 6l and neu have 5mm shafts, so you could go up to a 25t mod1 pinion and 40t revo spur. That should get some serious speed, and heat.

Anymore suggestions before I order.....

I will either go MM or 9920 on the ESC's and then have to decide on the motors. May go ahead and order the ESC's today if I can find the 9920 preferable or the MM as a backup in stock

What are they calling a monster truck? Could you run a smaller truck? Is there a tire size limit? Are you allowed to run with no body?
Keep it as close to 10 pounds a possible. Run the best batteries you can find. If you need to run an E-maxx size truck with a large tire I think 65 to 75 mph is going to be very hard on 3s. Would think in the 50 mph range would be closer.
Not sure haven't tried all the new motors/speed controls/batts out there.

Promod

Hey Barry! good to see you are still around.

Did you get a change to test the flightpowers yet?

well, while you where not around, not much has happened. Neu motors are pretty hot nowadays, 4 polers with an awful lot of torque. Neu also carries batteries now (lipo)

on 3S 60mph would be pretty hard, it requires roughly 2000 watts on a normal maxx; so that would be roughly 180A of current. It requires a motor with a very low internal resistance to be able to handle/drain that from the batteries.

I don't think it will be terribly hard to get to 60. My Maxx was running 50 on 12 cells with a XL3100.

60 on 3S is a totally different bag though.

Promod was the first to get in the 50mph zone with the XL3100 on 12 cells. I remember i pointed you to that thread on another forum squee.

Never did test the flightpowers, still setting on the shelf not even used. Been thinking about putting a truck together.
Need to do some reading and catch up in the new stuff. Just a noob now.:mdr:

That is exactly what I was thinking, 60 in an E-maxx size truck is asking alot for 3s.

Promod

I noticed you sold your twinforce? how about the new 3905 max? comes with 2 steel gears in the gearbox, singlespeed, camshaft servo saver and pretty tough driveshafts.

squeeforever, not saying it can't be done. But with a 10 pound E-maxx size truck with E-maxx size tires it will be very very very hard.
Find out exactly what the rules are and and look at the best ways to cheat. I mean think outside the box:lol:.

Promod

Are those new trucks strong? Not a money pit like the old E-maxx I hope. Really don't know a thing about them. Would run 3 or 4s.

Promod

Would be fine;

They updated the diffs as well; still two planetary gears with two satelites, but they upgraded it with an extra steel insert. (tunable with silicone-oil) they also increased the chassis length, and lowered the entire CG of the batteries a bit.

here, the exploded with the diffs;
http://www.traxxas.com/PDF-Library/3905_rear.pdf

Thank you for the information!



Promod

Yea, I think a twin setup using MM's and possibly something like high KV 1509's, Komodo LP's and a low stance with a wing. It should be be possible to see 60 or maybe 65.

I think it can be done. Kind of like what I said before, if one 5lb stampede can go 65 mph with one motor on 3s (the vxl system for example which is close to a cm4600), a 10lb exmaxx should be able to go 65 mph with 2 motors and two 3s packs. Its simple math. Also, I bet Promods 12 nimh cells back then dont even come close to comparing to the capability of the best 3s packs, which you could improve even more by adding cells in parallel. And on 3s I bet one lehner 3100 xl motor will not even come close comparing to two cm5700s for that matter.

Hmm, perhaps he should go with two Lehner XL's?

Honestly, it is not the motors that concern me but the batteries and ESCs. To achieve decent wattage, high capacity cells will be needed. Then high amp ESCs will be needed. This is going to get expensive very quickly.

Matt

Blew the dust off my old eagle tree data. I have 4 different motors that were tested on 12 cells. A Hacker 7XL, Hacker 9L,basic 4200 and XL3100. All pulled over 1000 watts with the XL3100 being the highest at 1200 watts. But the Hacker 7XL was the fastest in the truck. Ran 4 or 5 different dual motor setups but can't find any data on them.
At least for me larger motors always seemed to run higher top speeds. They seemed to be able to pull a much higher gear compared to a smaller motor.


Promod

I agree Promod...that old saying....

No replacement for displacement.

I think 2 Nemisis 6XL's and 2 9920's would be a solid combo on 3S. Will need some heavy duty 3's though.

30c fp's.