Help me pimp my nephews Stampede 4x4

[DukeMinnix]

So, my nephew Blake is an avid wrestler, and because of my RC trucks, he talked his dad into getting him one. They went to our local hobby store and got taken for a ride and ended up with a brushed Stampede 4x4. I know little to nothing about them, but I know Blake wants to go faster and jump higher. Knowing this I struck a deal with him. In a few weeks, he goes to a national meet somewhere in Indiana and has the chance to become an All American wrestler at the age of 8. Pretty bad ass if you ask me. I told him that if he went out there and took care of business and came back an All American, we'd take his truck to the next level and get him a brushless setup and some Lipos. Does anyone here have one with the stock Velion system? Can get it for about 170 motor and ESC straight from traxxas, but that seems high to me when I could get him castle setup for not much more. Any thoughts and advice is encouraged and welcomed.

 

[Jim85IROC]

The brushed Stampede 4x4 has a couple parts that differ from the brushless, most notably the diff gears.

The 4x4 brushed has a 12/47 (3.9:1 ratio) ring & pinion set in the diffs.
The 4x4 VXL has a 13/37 (2.8:1) ring & pinion set in the diffs.

•Traxxas #6755 Aluminum Drive Shaft
•Traxxas #6888X drive shaft adapter
•Traxxas #6879 Front Differential Ring and Pinion Gears
•Traxxas #5379 Rear Differential Ring and Pinion Gears

This gear ratio difference means that a brushless motor swap won't give you the same kind of speed that it will in a VXL Stampede unless you make some changes. You could swap in the VXL diff gears, adjust your pinion/spur ratios, or select a higher KV motor. Personally, I'd keep the diff gears as-is, because I find that the VXL Stampede is over geared and there's not much room to gear down. Having a lower ratio diff gear set will let you run larger pinions on the motor to help dial in your best running temps.

Another issue with going to brushless is that the plastic center driveshaft in the brushed truck probably won't handle the abuse for long. The aluminum shaft from the VXL (TRA6755) can be used along with the adapter part TRA6888X.

Aside from that, you need a motor & ESC. There are a lot of options out there, but my vote for best value goes to a Hobbywing EZRun 60A ESC and a Tacon 3500kv 3650 can. I use this combo in my dad's Ruckus. It's very much equal to the Velineon 3500kv motor in terms of power and speed. With the standard VXL gearing it might suffer the same overheating issues that the Velineon motor does, but geared down in the brushed Stampede, I think it'll be fine.

There's also no shortage of 3660 & larger motors out there, including some very inexpensive ones on ebay. I've used some of those inexpensive motors and I really like them, but to be honest, even that Tacon motor is going to be a lot for an 8 year old to handle. My 8 year old has a 3100kv 3650 can in his Circuit and he can't control it at all. He's been driving that circuit for 4 years, and did great with it right up through the 17 turn brushless I had in it prior, but upgrading him to this 3100kv motor was too much for him. That Tacon in the geared down brushed chassis should be pretty controllable though, especially if you use the punch control and the slipper clutch to help tame the bottom end.

 

[DukeMinnix]

The brushed Stampede 4x4 has a couple parts that differ from the brushless, most notably the diff gears.

The 4x4 brushed has a 12/47 (3.9:1 ratio) ring & pinion set in the diffs.
The 4x4 VXL has a 13/37 (2.8:1) ring & pinion set in the diffs.

•Traxxas #6755 Aluminum Drive Shaft
•Traxxas #6888X drive shaft adapter
•Traxxas #6879 Front Differential Ring and Pinion Gears
•Traxxas #5379 Rear Differential Ring and Pinion Gears

This gear ratio difference means that a brushless motor swap won't give you the same kind of speed that it will in a VXL Stampede unless you make some changes. You could swap in the VXL diff gears, adjust your pinion/spur ratios, or select a higher KV motor. Personally, I'd keep the diff gears as-is, because I find that the VXL Stampede is over geared and there's not much room to gear down. Having a lower ratio diff gear set will let you run larger pinions on the motor to help dial in your best running temps.

Another issue with going to brushless is that the plastic center driveshaft in the brushed truck probably won't handle the abuse for long. The aluminum shaft from the VXL (TRA6755) can be used along with the adapter part TRA6888X.

Aside from that, you need a motor & ESC. There are a lot of options out there, but my vote for best value goes to a Hobbywing EZRun 60A ESC and a Tacon 3500kv 3650 can. I use this combo in my dad's Ruckus. It's very much equal to the Velineon 3500kv motor in terms of power and speed. With the standard VXL gearing it might suffer the same overheating issues that the Velineon motor does, but geared down in the brushed Stampede, I think it'll be fine.

There's also no shortage of 3660 & larger motors out there, including some very inexpensive ones on ebay. I've used some of those inexpensive motors and I really like them, but to be honest, even that Tacon motor is going to be a lot for an 8 year old to handle. My 8 year old has a 3100kv 3650 can in his Circuit and he can't control it at all. He's been driving that circuit for 4 years, and did great with it right up through the 17 turn brushless I had in it prior, but upgrading him to this 3100kv motor was too much for him. That Tacon in the geared down brushed chassis should be pretty controllable though, especially if you use the punch control and the slipper clutch to help tame the bottom end.

good info here, I knew about the center shaft and was planning on having one on hand to upgrade when needed, I did not know about the different diff gears, thats good to know.

I actually have a hobby wing sc8 in my cart along with a GoolRC 3660 2600kv motor. I found this combo to be recommended on the traxxas forums after posting my initial question here. Guys seem to think 3s is the sweet spot for speed here, so I'm thinking changing the pinion to control heat and running 2s may be the way to go for Blake right now, with the ability to swap pinions and run 3-4s down the road.

 

[Jim85IROC]

Not a bad idea. I run a 2650kv 8th scale motor on my Slashpede with an SC8 on 3s. It's an animal. 47mph and wheelies at all speeds. I geared it down to slow it down and to control cogging. It still goes 35 and can run all day on a 5000mah pack.