MMP SCT 2400 in a slash 4x4

[Cornholio]

So after my VXL died I decided on the MMP SCT 2400. I installed it today and did the calibration, put in a 3s and hit the back yard. I was a little disappointed at the speed , it seemed about the same as the VXL on 2s. Should I just assume that the MMP doesn't really come alive until the 4s or so?

 

[Sixtysixdeuce]

That MMP combo is a 2400 KV motor; do the math.

If your stock motor was the 3,500 KV, on 2S (8.4v) it would free spin at 29,400 RPM

A 2,400 KV motor on 3S (12.6V) will run 30,240 RPM

Ergo, your top speed should be roughly the same if you did not change gearing. You can gear up a little, though my personal experience running SCTs on 3S with 1/10 electronics has been less than good, and gearing it taller will only further strain the system. IMO, due to the size and weight, SCTs should be given 1/8 scale bits when you want to push them harder. I'd bet on short ESC life if you start hitting that thing with 4S.

In my Prolite, I dropped the stock 3,500 KV 550 can and XP900SC ESC in favor of a Kyosho Vortex 2,000 KV 1/8 can and a Hobbywing SC8WP 1/8 ESC. I also went from a 14T pinion to a 20T pinion, thus my top speed is about 20% lower on the same 3S battery, but the motor doesn't strain near as hard. I could gear it up further (or run 4S), but the thing is plenty fast as is, still able to run 47 MPH.

 

[Cornholio]

Well, I did some more reading and it looks like a lot of people are running 4s and not having any problems. It's rated for 3s-4s anyway. I've got fans on the motor/esc, but it's suppose to run fairly cool anyway. I guess I'll find out soon enough!

 

[Sixtysixdeuce]

It'll likely just depend on how hard you push it. I run the snot out of my kits, and as such, have found it necessary to run systems rated above my intended use. If I want to run 3S, I use a 4S rated ESC. To run 4S, I go with 6S rated controllers. I'm not interested in having to wait for them to cool down, so it is necessary for me to use components that afford a much greater margin.

 

[Cornholio]

I understand what your saying, makes sense. I run fairly hard, but not over the top. I've got a pair of 2's I can put in together tomorrow, I'll see how that goes. 4's are just so damn expensive!

 

[Sixtysixdeuce]

4's are just so damn expensive!

http://www.ebay.com/itm/221256147779?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

If you don't mind soft case, these are decent. I'm running one in my e-801Xt:

http://www.ebay.com/itm/D9K-Akku-Wi...Control_Parts_Accessories&hash=item540396b249

 

[Cornholio]

Well heck, thats not too bad. I get my glo plugs from over there, shipping time isn't all that terrible..a week or so usually. Beats the heck out of paying $70-80 here.

 

[Cornholio]

Well, I ran a pair of 2's together today after a 3's and the motor did very well. Temps were very cool. The only problem I had was when running the (2) 2's full throttle the tires would balloon so badly they would hit the body. I think its more than enough speed, so that I don't have to change the gearing...sure I could go faster, but crashing at that speed probably wouldn't be pretty. Thank goodness for the RPM front bumper though, I clipped a man hole cover sticking up out of the ground about 4 inches at a construction site, flipped the truck and only scratched the bumper. Thanks RPM, woot!