"Speed Running" My SG 1601 brushed (AKA HBX 16889)! How fast will it go?

[The_RC_Dude]

Hi guys, Isaac here. As some of you may know, I recently got a new car, an MT, the SG 1601 brushed (rebranded HBX 16889) about two months ago. I was wondering about the actual speed of this rig, before we go any further, bear in mind, this is a 1/16 scale, brushed (390 size motor) MT that weighs 1.8 pounds, so don't expect 60mph! I searched on YT, I found somewhat limited speed run results on this rig, either the person was judging it by eye, running it in gravel or grass, ect. I came across Perth West Oz RC's speed run video, he got 17.1mph. And yes, the results from the HBX 16889 will be the same as the SG 1601, as they are the same car, save for the color of the body shell.

So, the other day I went to a school parking lot, and did my first ever speed run, with any RC! Since I don't have a GPS or something like that, and didn't feel like spending the $35+ for this, I taped an older Samsung phone to the chassis, on top of the top deck, it fit in surprisingly well! Plus, it all fit under the body shell perfectly!

It was around 40f degrees I think, so the road was colder, and the tires weren't warm either, so if I were to do this again in late spring or summer, expect a speed increase of about 1mph. Also, the weight of the phone probably slowed the car down 1-2mph versus no GPS and using, say, a radar gun. So, what speed did I get, factoring all this in? I got 17mph, so in warmer conditions and without the phone, I'm thinking up to 19mph, which isn't too bad all things considered. I fully charged the stock, small 800mAh Li-Ion battery. I don't think a LiPo would increase the speed, maybe by .5mph, as this car currently isn't drawing too many amps speed running.

So, what do you guys think, do you have this rig or the HBX 16889, and what speed did you get?

-Isaac

Edit: Oh, and I may do this with my brushless Wltoys 144001 as well, except there's no way I'm fitting the phone under the body shell, so I guess I'll have to tape it to the rear wing or something!

 

[tntpoof]

there's a lot of rc gps units out .but most are way more than your rcs.. I have 4 in my collection a old Mageline and id never use a phone to track my speed just to big and bulky that will affect your top speed.

 

[ahr43]

Good for you, Isaac. Expect you will break that 20mph barrier soon. Speed running is infectious. Once you begin, you want more.

Sounds like you are making a balanced approach. First, get what speed the truck will give you. Once you establish a baseline, then you can begin adding on incremental speed. Did you snap any pictures of the cell phone install? And the track where you are running? Cheers. 'AC'

[Edit. Oops. Opened your attachment and there reads the speed. Bravo!]

 

[The_RC_Dude]

there's a lot of rc gps units out .but most are way more than your rcs.. I have 4 in my collection a old Mageline and id never use a phone to track my speed just to big and bulky that will affect your top speed.

My point exactly! You have 4 GPS's? Honestly, I don't need to see the exact speed, time, ect. of my cars, I'd rather spend that money on upgrades. I'm also not a speed runner, and as I said, this is the first every time I measured the speed of one of my cars! the phone was just to get a rough idea, and even with the phone in, I got 17mph, so in warmer conditions, and if I were to use something like a radar gun, I might hit 19mph! The phone was on the chassis, under the shell, so it probably had minimal aero affects.

Good for you, Isaac. Expect you will break that 20mph barrier soon. Speed running is infectious. Once you begin, you want more.

Sounds like you are making a balanced approach. First, get what speed the truck will give you. Once you establish a baseline, then you can begin adding on incremental speed. Did you snap any pictures of the cell phone install? And the track where you are running? Cheers. 'AC'

[Edit. Oops. Opened your attachment and there reads the speed. Bravo!]

Thanks Arnold! I'm really not a speed run guy, I'm a light basher TBH. It was kinda fun though, but with those stock friction shocks and the good brake on the ESC, I did flip the car end-over end a couple of times from full or near full throttle to full break, but those times, the phone wasn't recording (it was supposed to be, ironic!), so the flips didn't effect the speed. Proper oil-filled shocks will be one of my first upgrades, must have!

I'll try to get you a pic of how I attached the phone (don't laugh...I'm not a pro!), and my goal for either of my cars is not for speed running, but for bashing. I'm probably gonna have my SG 1601 as my moderate off-road basher, as it's an MT and all, and my brushless Wltoys 144001 as a light off-road basher and a street ripper (just because it handles better, and it's more of a pain than the SG to clean after off-road bashing).

My brushless converted 144001 should hit round about 37-38mph, and that's with the small 2440 4600kV motor and 35a ESC! I'm thinking about transplanting the brushless motor and ESC in my 144001 to the SG eventually, and getting a 2838 or 2845 motor and a HobbyWing 30a ESC in my 144001 (which should be the final electronics change!).

The SG is fine stock, but compared to my 144001, it lacks a little "oomph" and lightning acceleration, but we're comparing a brushed motor to a brushless one! As I said, I didn't go to a speed run location, because this car is smaller and doesn't go super fast, I didn't need a super long strip. I ran at a school parking lot, it's not massive, but I was able to go "full-pin" for a good 3 or 4 seconds!

After the brushless swap on my cars, I'm hoping the SG will crack 25mph, and of course, it'll run even cooler (stock, even brushed, it runs very cool and effeciently!), wheelie all day, and have longer battery life.

Thanks for the kind words and adivce!

-Isaac

 

[ahr43]

No problemo, Isaac. Can you set in more drag brake? That might prevent the endo's your truck experienced. Good luck. 'AC'

 

[The_RC_Dude]

No problemo, Isaac. Can you set in more drag brake? That might prevent the endo's your truck experienced. Good luck. 'AC'

Nope, since it's a more budget style car, it has one of those dang ESC/receiver combos, and as far as I know, the ESC isn't adjustable. It has good brakes, which I would prefer over weak brakes, it's just a combo of good brakes, a light truck, good/decent tires, and friction shocks working together. If you're going at/nearly full throttle and give it brake, it will actually do a full front flip, landing right back on the wheels if you have a little luck! The oil-filled shocks don't help, since they have pretty much 0% dampening and full rebound (so to speak, you can see one of my other hobbies, Mountain Biking, coming out here, when talking about shocks!), so it bucks the rear end really bad on jumps, and the weight transfer is very sudden, so it decreases grip and the in-air-handling. No problem though, 4 oil filled shock can be had for under $24!

I actually have filled the shocks with grease, as I've heard doing so on friction shocks makes them less "springy", but it only made a marginal difference, now they're smoother but I probably shouldn't have put that much grease in (now, after runs, there's more grease over the shocks, but it's getting better as the excess grease runs out and is wiped away)!

Isn't a drag brake a function on the ESC where when you let the car "glide", without power, it'll slow it down more? I would think that if the ESC were adjustable, wouldn't less brake force be more helpful? I could be wrong though, I haven't messed with ESC setting before!

 

[ahr43]

Hey Isaac. Drag Brake slows the car with less drama. Return the throttle to neutral and let drag brake slow the car. Brake Force still relies on the trigger finger to apply braking. Tradeoff is drag brake tends to drain a lot of battery voltage compared trigger fingering it. A combination of the two is what I rely on. Use drag brake to slow the car off peak speed. Once it reaches a reduced controllable speed then I ease into trigger brake.

Maybe it's just me, but I've found slowing the car controllably is a bigger challenge than accelerating it to speed and holding it there. I'm still in learning/re-learning mode on the speed thing myself. Cheers. 'AC'

[Edit. An aside. My MX-V radio system had a no-lock braking feature that I really liked. Remember the sound that protagonist's pod racer made in Star Wars? That beep-beep-beep stutter. That's the way the non-skid worked with the MX-V. I'm really going to miss not having that feature on the Futaba 4PLS.]

 

[The_RC_Dude]

Hey Isaac. Drag Brake slows the car with less drama. Return the throttle to neutral and let drag brake slow the car. Brake Force still relies on the trigger finger to apply braking. Tradeoff is drag brake tends to drain a lot of battery voltage compared trigger fingering it. A combination of the two is what I rely on. Use drag brake to slow the car off peak speed. Once it reaches a reduced controllable speed then I ease into trigger brake.

Maybe it's just me, but I've found slowing the car controllably is a bigger challenge than accelerating it to speed and holding it there. I'm still in learning/re-learning mode on the speed thing myself. Cheers. 'AC'

[Edit. An aside. My MX-V radio system had a no-lock braking feature that I really liked. Remember the sound that protagonist's pod racer made in Star Wars? That beep-beep-beep stutter. That's the way the non-skid worked with the MX-V. I'm really going to miss not having that feature on the Futaba 4PLS.]

That's what I thought, thanks! Both my cars don't have strong drag brake, on my buggy, that's fine, I haven't flipped it, or endoed it before under braking, but I haven't tried full brake from full/near full throttle. I know how to feather the throttle or brake, I just had to try giving it full brakes from higher speeds!

Yeah, during acceleration or braking, the car can slide out, spin out, or just lose grip! As I have learned with my MT, braking is sometimes more of a handful like you said, but then again, it depends on the driver and car, just about any car can be a handful both ways! Hmm, that's a cool feature, an anti-brake-lockup feature! I don't have that feature on my radios, but sometimes I'll lock the wheels up on my buggy when turning at slower speeds to whip the rear end around, like how a hand-brake would work.

-Isaac

 

[BrandonDrums]

I actually love the Brushed 16889, they are plenty fast for my 5 year old son while still being slow enough to prevent endless self-destruction on the curb. I'm a long time RC guy though so as he grows I'll get back into more hardcore stuff and also dust off my RC planes and such.

Out of curiosity, anyone know the specs of the OEM brushed motor for the 16889's? I know it's a 390 motor with at least a 9V rating but no idea of KV.

 

[The_RC_Dude]

I actually love the Brushed 16889, they are plenty fast for my 5 year old son while still being slow enough to prevent endless self-destruction on the curb. I'm a long time RC guy though so as he grows I'll get back into more hardcore stuff and also dust off my RC planes and such.

Out of curiosity, anyone know the specs of the OEM brushed motor for the 16889's? I know it's a 390 motor with at least a 9V rating but no idea of KV.

I like my SG 1601 too, as I've said, they're the exact same car, just different branding, and body shell color, that's seriously it. (Nuts, I just realized I said that in my OTHER SG 1601/BHX 16889 thread, "It's new RC day!")

Anyway, about the OEM brushed motor specs, you're probably right with the 9v rating, I wouldn't push it past that though, it's really only meant for 2s, the ESC even has a sticker on it saying something like "2s LiPo only" for those who were toying with the idea of 3s The Wltoys 144001 (and the 124019/8, and basically all the other >1/18 scale brushed cars) doesn't take 3s, with the stock system, too well. The electronics are built for 2s, and the tall gearing doesn't help. With the 144001, I've heard that you might get a few passes out of it on 3s before the dreaded "magic smoke" comes out of the ESC and/or motor. The 16889 is geared more conservatively, but I wouldn't ask the little 390 brushed motor and the ESC, which I'd guess to be rated at <30amps, I can't find the max amp rating anywhere on the internet, but it's probably like 25-30a.

So yeah, TLDR, I don't recommend trying to use a 3s LiPo in the 16889 brushed (you *could* try your luck with 3s with the 16889 brushless, or the 16889A Pro, but do it at your own risk, and good luck keeping the front wheels on the ground, for that matter, good luck keeping the car on the rear wheels and not the roof, even with the wheelie bar!). You'd also have a heck of a time trying to find and fit a 3s LiPo that fits in the stock battery tray, you'd have to get one for like a mini RC quadcopter.

So for brushed motors, they don't use "kV" (which is roughly how many RPM per volt, so a 4600kV motor, like the one I have in my 144001, will do roughly 4600 RPM @ 1v, theoretically, so it would do a little over 38, 500RPM with a fully charged 2s @ 8.4v, in theory, but there's resistance from the wires, and such). The RPM of brushed motors is measured in "turns", or "t". Now, TBH, I don't know a lot about the turn of a brushed motor, but from what I can tell, a lower turn brushed motor is faster than a higher turn one. So I'm assuming the turn of a brushed motor is like the kV of a BL motor, but reversed, as a higher kV BL motor is faster, whereas with brushed motors, a LOWER turn rating is faster. This most likely means that a higher turn motor is slower, but has more torque than a same size, lower turn motor, and vise versa. So bear in mind, it's a tradeoff, a lower turn motor is faster, but has less torque. I found this article, it fills in some of the gaps in my explanation.

Anyway, getting back on track (I seem to go off track a lot ), I have no idea of the t rating of the 16889's brushed motor, I can't find any info of it on the web! Anyone who has a 16889 brushed motor and is will to take it apart and count the number of times the wire is wrapped around the armature of the motor is welcome, and please report back with your finding! Unfortunately, I can't really provide an estimate as I've had limited experience with brushed, or brushless for that matter, motors. I can say that the 390 brushed motor is probably >10t, but <21t, as the motor is not super fast, but not crawler-motor slow and torquey either. Hope this helps! I checked the printing on my SG 1601's motor, and it doesn't say what turn it is, only the manufacturing date and some other stuff that I can't remember (I can copy that stuff here if you would like me to)!

So, TLDR, I recommend sticking with 2s with these cars, especially on the brushed models, and the turn of the stock brushed motor is unknown, but I'd guess it to be higher than 10t, but lower than 21t.

Hey Isaac. Drag Brake slows the car with less drama. Return the throttle to neutral and let drag brake slow the car. Brake Force still relies on the trigger finger to apply braking. Tradeoff is drag brake tends to drain a lot of battery voltage compared trigger fingering it. A combination of the two is what I rely on. Use drag brake to slow the car off peak speed. Once it reaches a reduced controllable speed then I ease into trigger brake.

Maybe it's just me, but I've found slowing the car controllably is a bigger challenge than accelerating it to speed and holding it there. I'm still in learning/re-learning mode on the speed thing myself. Cheers. 'AC'

[Edit. An aside. My MX-V radio system had a no-lock braking feature that I really liked. Remember the sound that protagonist's pod racer made in Star Wars? That beep-beep-beep stutter. That's the way the non-skid worked with the MX-V. I'm really going to miss not having that feature on the Futaba 4PLS.]

BTW, do you have any speed run oriented cars, or what's your fastest rig? You seem to know your stuff with speed running!

 

[ahr43]

Hey Isaac. Still feeling my way on this speed run thing. I've some background from '07 and '08 running 80+mph RC drag racing electric top fuel and 60+mph passes with a 2.50sec Index Car '09-'11. Built my own chassis. Long time ago. Things have changed.

Have four active cars. Two Rustlers and two MT-10's. One each for fun and one each to [speed] run. Speed is a relative thing, though. At least for me. If I can pull a consistent 50mph out of Rusty and 60mph out of the MT-10, that will satisfy me. Too old and too slow to react quick enough to get a car out of trouble these days. By the time I realize something bad is going to happen, it already has. Still get a thrill out of it. Like the wrenching too.

You are close enough regarding your comments on brush motors and turns. It captures the essence of the difference between low and high turns. The top fuel electric ran an 8-Turn rare earth magnet motor on 8 NiMH cells. The Index rail ran a 10.5T brushless on a 2s LiPo. The slower of the two cars was more fun. It could actually be driven out of trouble whereas the top fueler was more-or-less "aimed" down the track. Fire and forget, so to speak, describes a run.

Anyways, wandered a bit here on your thread. Hope there's something somewhere in all this that helps. Apologies. Cheers and good luck. 'AC'

 

[The_RC_Dude]

Hey Isaac. Still feeling my way on this speed run thing. I've some background from '07 and '08 running 80+mph RC drag racing electric top fuel and 60+mph passes with a 2.50sec Index Car '09-'11. Built my own chassis. Long time ago. Things have changed.

Have four active cars. Two Rustlers and two MT-10's. One each for fun and one each to [speed] run. Speed is a relative thing, though. At least for me. If I can pull a consistent 50mph out of Rusty and 60mph out of the MT-10, that will satisfy me. Too old and too slow to react quick enough to get a car out of trouble these days. By the time I realize something bad is going to happen, it already has. Still get a thrill out of it. Like the wrenching too.

You are close enough regarding your comments on brush motors and turns. It captures the essence of the difference between low and high turns. The top fuel electric ran an 8-Turn rare earth magnet motor on 8 NiMH cells. The Index rail ran a 10.5T brushless on a 2s LiPo. The slower of the two cars was more fun. It could actually be driven out of trouble whereas the top fueler was more-or-less "aimed" down the track. Fire and forget, so to speak, describes a run.

Anyways, wandered a bit here on your thread. Hope there's something somewhere in all this that helps. Apologies. Cheers and good luck. 'AC'

RC cars went that fast 14-15 years ago?! And on NiMH packs no less?! What's an "Index car"?

Seems like you like to have two of each car, so you can be consistent, and the handling will be familiar? Yeah, I get that rush too when "blasting" down the street at 20mph (lol my buggy can do a hair under 40 with new tires, but I'm a more conservative driver and don't go WOT all day long)! I like to go slower too, a lot less breakages, less strain and wear on the whole car, just more laid-back, car gets less filthy, and the batteries last even longer! Also a smaller threat to your and others' ankles! Wrenching is fun too for me, until it gets real messy, or like major dissection!

Is the "8-Turn rare earth magnet motor" you mention brushed or BL? Aim and pray huh... Like a bullet!

Oh, no worries, the more you learn, the more you know! And I wander off track and ramble a lot, lol!