Big Rock Arrma Big Rock BLX V3 Motor Upgrade

[SeaBass]

Hello!

I am a complete newbie to the sport and looking for suggestions on what motor I should use. I recently purchased a Big Rock BLX V3 and upgraded almost everything with Hot Racing parts, M2C Racing, T-Bone Racing, and Spektrum. The car is upgraded tough and the only main factory item I have is the motor. I have an upgraded Spektrum servo S6280, Firma 150A Smart ESC, Arrma HD Steel Spur Gear, and 4s battery. With all these upgrades what Spektrum motor should I get? I want to keep the motor with Spektrum brand. Can my upgraded ESC work with stock motor? I’m not trying to get an overkill motor where it does non stop wheelies. A 4S battery will be the max I use. I want the car to be as stable as possible, and reliable. Any suggestions?

 

[slick2500]

I can tell you are a complete newbie by wanting to stick with Spektrum. Their electronics are junk and overpriced., Literally any other brand would be better. I would look at something like this for a motor https://www.ebay.com/itm/333250722638?hash=item4d974a7b4e:g:hzYAAOSwObFgqnGY

 

[SeaBass]

I can te

I can tell you are a complete newbie by wanting to stick with Spektrum. Their electronics are junk and overpriced., Literally any other brand would be better. I would look at something like this for a motor https://www.ebay.com/itm/333250722638?hash=item4d974a7b4e:g:hzYAAOSwObFgqnG

 

[Kla912000]

I agree with Slick. Any other brand motor would be better than a Spektrum motor. Hobbystar, Hobbywing, Surpass Hobby....to name a few. 3665-3675 size motor in the 2200kv-2650kv range would be a good 4s motor.

 

[Velodromed]

I also agree with the above. Don’t get another spectrum motor. For around 35 to 40 bucks you get a surpass or Hobby star 3665 or 3670 can with a KV between 2400 to 3050 and it’ll do wonders for the truck. If you intend to go 4s stick with the lower KV like both said above.

You have added a lot of weight to that car it sounds like. Did you upgrade the shocks? Stock ones will struggle. Are you going to jump the car? You should expect damage if you do. These things are mostly plastic stock and extremely tough because of the light weight. When you change that it’s not always for the best. Good luck!

 

[SeaBass]

I also agree with the above. Don’t get another spectrum motor. For around 35 to 40 bucks you get a surpass or Hobby star 3665 or 3670 can with a KV between 2400 to 3050 and it’ll do wonders for the truck. If you intend to go 4s stick with the lower KV like both said above.

You have added a lot of weight to that car it sounds like. Did you upgrade the shocks? Stock ones will struggle. Are you going to jump the car? You should expect damage if you do. These things are mostly plastic stock and extremely tough because of the light weight. When you change that it’s not always for the best. Good luck!

I appreciate everyones response. I wanted to stick to a spektrum motor for marketing reasons as I am in the process of starting a YouTube channel. is their any type of smart motors for getting certain telemetry or is that all coming from the ESC? I am upgrading my shocks to the Typbon 6. Yes I plan on jumping my car. I’ve also upgraded the CVD and gpm turnbuckles.

 

[SeaBass]

Would it be bad if I used my stock motor? It’s rated 3200kv.

I agree with Slick. Any other brand motor would be better than a Spektrum motor. Hobbystar, Hobbywing, Surpass Hobby....to name a few. 3665-3675 size motor in the 2200kv-2650kv range would be a good 4s motor.

Thanks for keeping it simple! I’m still learning

 

[slick2500]

I can te

you think you know it all. I didn't ask for criticism but instead my question was specific that your mind would not understand. Theirs a way to recommend an item and that’s not the way.

Wasn't trying to come across like a Richard. The Spektrum electronics are just that bad that you really should avoid them like a hand grenade dipped in Aids. Just search Spektrum and garbage in the search box.

What marketing reasons would require you to run just Spektrum electronics on your Youtube channel?

The motor doesn't have anything in it that effects the telemetry, the telemetry will work with any motor. Speed is handled via the gps module, motor temp is handled by an external temp sensor and voltage is handled by the esc.

If you are adamant about sticking with Spektrum this is the best option they have for your application and what you want to do. It doesn't even have a proper product page and I cannot find it for sale anywhere in the US https://www.spektrumrc.com/Products/Default.aspx?ProdID=SPMXSM2100

This one will work as well but it is a 4074 sized motor, it is heavier and quite a bit larger than the above motor. The stock 3s motor heatsink will not fit. https://www.spektrumrc.com/Products/Default.aspx?ProdID=SPMXSM1700

 

[Roadkill69]

Dam he asked for advice not a dog pile. I am a castle fan just my two cents.

 

[dure16]

I’d personally just run your stock motor on 4S. Move down a couple pinion sizes to 12T or 13T.

Yes it will probably ruin the stock motor over time but who cares. You’re planning to take it out of the truck anyway.

If/when the stock motor breaks, I’d recommend castle/hobbywing for a quality motor or surpass/hobby star for a cheap motor. I would never buy a spektrum motor.

 

[Hector_Fisher]

I’d personally just run your stock motor on 4S. Move down a couple pinion sizes to 12T or 13T.

Yes it will probably ruin the stock motor over time but who cares. You’re planning to take it out of the truck anyway.

If/when the stock motor breaks, I’d recommend castle/hobbywing for a quality motor or surpass/hobby star for a cheap motor. I would never buy a spektrum motor.

Unless you're planning to save the stock motor for something else, you might as well do this ^^^

What was the purpose of a motor upgrade? Is the stock motor not meeting your needs in some way (ie., need more torque, less weight, run cooler, etc)? The answer to that may help guide as to which motor to buy. However, if you just want a new motor, almost any motor you choose would make the car go forward.

 

[Crunchy Gears]

If primarily running 4s just run a 12 tooth Pinion and keep the stock 3s motor till it dies. Mine is still going strong.
Unless you're sponsored by Spektrum though I don't see how you need a particular brand for a YouTube channel?

Wait for the 4s line to come back and order the 2400kv Slick linked you to off of Jenny's for cheap if you still need spektrum electronics by then.

I don't hate spektrum they've done fine for me so far. But a 2 minute scroll through the build threads and problem topics show alot of people have. I see them as stock electronics, Not upgrades.

 

[SeaBass]

Thank you all! I decided to purchase the Specktrum SPMXSM1700 Firma 2050Kv which was a bundle with the smart ESC 150A. I have 1 last question. Based on the motor and 4s battery what pinion size should I use? I'm using the stock pinion for the BLX v3. Really appreciate so much feedback. Stepped away for a day and came back to so much info! I promise to share project when done. I haven't even driven it yet!

Unless you're planning to save the stock motor for something else, you might as well do this ^^^

What was the purpose of a motor upgrade? Is the stock motor not meeting your needs in some way (ie., need more torque, less weight, run cooler, etc)? The answer to that may help guide as to which motor to buy. However, if you just want a new motor, almost any motor you choose would make the car go forward.

purpose of motor upgrade is for speed and reliability to match other upgrades.
I know I'm not listening to most people but I promise I have a reason and still value everyone's input! If the upgraded Spectrum motor goes out on me I'll look for something else at that time.

 

[dure16]

Based on the motor and 4s battery what pinion size should I use?

Depends on your goals. An 18T pinion would give you a similar top speed as your stock setup.

I use the “Gear Speed” iPhone app to play around with gearing options. It’s worth checking out. The internal transmission ratio on your truck is 2.850.

 

[slick2500]

Thank you all! I decided to purchase the Specktrum SPMXSM1700 Firma 2050Kv which was a bundle with the smart ESC 150A. I have 1 last question. Based on the motor and 4s battery what pinion size should I use? I'm using the stock pinion for the BLX v3. Really appreciate so much feedback. Stepped away for a day and came back to so much info! I promise to share project when done. I haven't even driven it yet!

purpose of motor upgrade is for speed and reliability to match other upgrades.
I know I'm not listening to most people but I promise I have a reason and still value everyone's input! If the upgraded Spectrum motor goes out on me I'll look for something else at that time.

Their motors are fine but I would keep an eye on the bearings in them, they seem to be a common failure point. Jim's Bearings has a kit for them and it's pretty cheap. Yes it says BLX185 but they are the same motors https://jimsbearings.com/collections/arrma-motor/products/arrma-blx185-2050-motor-bearings
He also does ceramics but they are out of stock https://jimsbearings.com/collection...ceramic-motor-bearings?variant=32307800801342

 

[SeaBass]

Their motors are fine but I would keep an eye on the bearings in them, they seem to be a common failure point. Jim's Bearings has a kit for them and it's pretty cheap. Yes it says BLX185 but they are the same motors https://jimsbearings.com/collections/arrma-motor/products/arrma-blx185-2050-motor-bearings
He also does ceramics but they are out of stock https://jimsbearings.com/collection...ceramic-motor-bearings?variant=32307800801342

I actually already been replacing all bearings with Jim's Ceramic set.

 

[SeaBass]

Depends on your goals. An 18T pinion would give you a similar top speed as your stock setup.

I use the “Gear Speed” iPhone app to play around with gearing options. It’s worth checking out. The internal transmission ratio on your truck is 2.850.

So are you saying the stock pinion will make my car slower with all upgrades? I read that Big Rock BLX stock pinion is 15T.

 

[Kla912000]

With the 2050kv motor the stock 15t pinion will be slower than the stock 3200kv motor. Its common sense. That's why you need to gear up to gain speed with a lower kv motor.

 

[SeaBass]

With the 2050kv motor the stock 15t pinion will be slower than the stock 3200kv motor. Its common sense. That's why you need to gear up to gain speed with a lower kv motor.

Got it. I'm new to this. So 18T is your best suggestion? Reliability is the most important to me, stability, and then speed. I don't want it to be non stop wheelies. Do you have a link to what pinion to purchase? Thanks!

 

[Kla912000]

Got it. I'm new to this. So 18T is your best suggestion? Reliability is the most important to me, stability, and then speed. I don't want it to be non stop wheelies. Do you have a link to what pinion to purchase? Thanks!

Don't have a link but Robinson Racing would probably be the best pinion you can get. Or Tekno pinions are very good also. But any 5mm shaft pinion will work as long as the pitch is either mod 0.8 or 32p in whatever tooth count that you prefer.