Biggest motor for Slash 4x4?

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Dan B.

Area man
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Messages
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Location
Southern Vermont
RC Driving Style
  1. Bashing
  2. Crawling
I’m building a low cg 4x4 Slash street ripper next week (kind of a rally at this point) and was wondering if anyone had experience with a 42mm or bigger can fitting without serious mods? I’d love to put a 1/8 combo in it that can run 4-6s. I’m partial to HobbyWing, but considering Castle combos just for the Castle Link data capabilities. I would really appreciate your thoughts on this from anybody with experience in this setup.
 
so you think a slash can handle 4+ cells...traxxas will love its new best customer. I put a 550 can in a guys years ago stayed on 2 cells top speed just over 75mph...
 
Greywolf put a 1/8 motor in his Rustler and got it over 100. You have to do a lot of mods to get it to fit.
 
I haven't tried with an LCG chassis, only the HCG. I run a blx185 (150Amp) esc and blx4074/2050kv in my slashpede HCG 4x4 on 4S. It is pretty crazy and requires other upgrades to deal with the power, but it's fun. :)

I don't do speed runs with it, geared for bashing in grass/jumping and it nearly takes flight off ANY little bump on the ground if I'm beyond 3/4 throttle.
 
I’m building a low cg 4x4 Slash street ripper next week (kind of a rally at this point) and was wondering if anyone had experience with a 42mm or bigger can fitting without serious mods? I’d love to put a 1/8 combo in it that can run 4-6s. I’m partial to HobbyWing, but considering Castle combos just for the Castle Link data capabilities. I would really appreciate your thoughts on this from anybody with experience in this setup.
I'm no expert on Slashes, but I'd say 6 is just too much power, you'll have to upgrade a lot of your drivetrain, and other stuff. 1/10 is really best for 4s and below I heard. 3s for hooning, and 4s for speed runs might be best. I know the Slash can take a lot of abuse, but a 1/8 scale electrics + 6s would be really pushing the limits.

Claire (from Claire's RCs) and Kevin Talbot both did a 6s project 100mph Slashes:
 
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so you think a slash can handle 4+ cells...traxxas will love its new best customer. I put a 550 can in a guys years ago stayed on 2 cells top speed just over 75mph...
You got 75mph out of a 550 brushed motor in a Slash? Was it like an 8 turn motor or something? That’s impressive.
I know a Slash can’t handle 3s without regularly scattering parts, let alone 4 or 6s. This build will be “Slash based” but with highly upgraded parts. It also won’t be bashed hard, it’ll be primarily a parking lot ripper and speed run vehicle. My other Slash bashers run 3300kv Reedy motors and absolutely require steel cvd’s or dog-bones, all hardened steel gears everywhere and spools in the diffs or they won’t make it a single pack on 3s without breaking something.
This one will be based on an aluminum LCG 4x4 chassis and built out of a kind of FrankenMix of Tekno, MIP, Vitavon, Arrma, Traxxas (XO-1) and assorted billet items to try and make it somewhat reliable.
It will have the Traxxas based driveline and motor mount setup, that’s why I was wondering what the max diameter “drop-in” motor would be.
I‘ve been waiting awhile to join the 100mph club, and I’m giving it a go with this project. I’ll post a build thread when it’s in the works.
 
I want to say his was rwd. The 4x4 has the motor sideways in chassis. The rwd should be easier.

I did find a link from the traxxas forums where someone installed a larger castle motor.

https://forums.traxxas.com/discussion/9005514/slash-4x4-buggy-1717-6s
Yes, @Greywolf74 had a 2wd. I just read that whole build link you provided, that was cool. A LOT has progressed in the last 7 or 8 years.
I’m focused, for better or worse, on hitting 100mph with a 1/10 4x4 road setup. I could be building up one of my larger scale Arrma‘s with better success and an easier build, but I‘m kind of drawn to this approach and looking forward to the challenge. 😊
 
You got 75mph out of a 550 brushed motor in a Slash? Was it like an 8 turn motor or something? That’s impressive.
I know a Slash can’t handle 3s without regularly scattering parts, let alone 4 or 6s. This build will be “Slash based” but with highly upgraded parts. It also won’t be bashed hard, it’ll be primarily a parking lot ripper and speed run vehicle. My other Slash bashers run 3300kv Reedy motors and absolutely require steel cvd’s or dog-bones, all hardened steel gears everywhere and spools in the diffs or they won’t make it a single pack on 3s without breaking something.
This one will be based on an aluminum LCG 4x4 chassis and built out of a kind of FrankenMix of Tekno, MIP, Vitavon, Arrma, Traxxas (XO-1) and assorted billet items to try and make it somewhat reliable.
It will have the Traxxas based driveline and motor mount setup, that’s why I was wondering what the max diameter “drop-in” motor would be.
I‘ve been waiting awhile to join the 100mph club, and I’m giving it a go with this project. I’ll post a build thread when it’s in the works.
TNT might have meant a 550 size brushless motor, in other words, a 3650-3660 size BL motor. With a good LiPo, ESC, appropriate gearing, foams (tires), aero body shell, ideal conditions, and a little luck, you could hit 75mph on 2s. Not to sound mean or anything, but at this point, would starting with an on-road chassis and design be easier? But if you have a specific reason, like already having a spare Slash and some parts, and you want to tinker and challenge yourself, then go for it! 👍

I still think that 6s is a bit much and will be a handful for a 1/10, unless you're really going for those top speed runs. Oh, never mind, you are trying to go fast. Still maybe a 4s pack would be better, and only stick a 6s in for a run or two. Just imagine the drivetrain stress, if you need to upgrade over half the drivetrain for 3s, you probably won't have a single stock drivetrain part left for 6s! You get the point...

I'm not sure about the max motor diameter that'd fit, but how about a "long can" 3670 or even 3680 with a high-ish kV? If you have the chassis length to fit one, then you could do that. Because a longer motor can means more torque (a 3650 and a 3670 will have the same RPM per given kV, but the 3670 will have a lot more torque), you can gear it up for speed.
 
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Totally agree with everything you said, and you’re correct in saying every single driveline component will have to be seriously upgraded. I like your idea of a 36xx long can motor, but I was hoping to squeeze in a 40 or 42mm can to allow for the 6s option (speed runs only) even though it would be running 4s the vast majority of the time.
I get what you’re saying about starting with an on road chassis, but the 4x4 lcg is also used for the dual surface Traxxas Rally, and the one I’m doing will be much lower.
It would be much easier to start with a short wheelbase Arrma 6s platform, but I have a pile of Traxxas stuff laying around.
 
Totally agree with everything you said, and you’re correct in saying every single driveline component will have to be seriously upgraded. I like your idea of a 36xx long can motor, but I was hoping to squeeze in a 40 or 42mm can to allow for the 6s option (speed runs only) even though it would be running 4s the vast majority of the time.
I get what you’re saying about starting with an on road chassis, but the 4x4 lcg is also used for the dual surface Traxxas Rally, and the one I’m doing will be much lower.
It would be much easier to start with a short wheelbase Arrma 6s platform, but I have a pile of Traxxas stuff laying around.
Sorry if I came across a bit harsh! I can't help you on the max motor diameter part, I have no idea! Do you have a rotary tool? You might need to make a small dip/indent in the chassis to fit a bigger motor. Traxxas does use their Slash chassis for a lot of stuff, it's very versatile, along with the Bandit and Rustler chassis's. Good luck, we'll follow your progress! :)
 
Sorry if I came across a bit harsh! I can't help you on the max motor diameter part, I have no idea! Do you have a rotary tool? You might need to make a small dip/indent in the chassis to fit a bigger motor. Traxxas does use their Slash chassis for a lot of stuff, it's very versatile, along with the Bandit and Rustler chassis's. Good luck, we'll follow your progress! :)
Not harsh at all, I appreciate knowledgeable feedback even if it differs with my current vision. That’s why I’m here! We can’t always imagine every consideration/downside to a plan, so I appreciate everyone’s take on this, especially to those with prior experience relative to the initial question. I broke out the caliper and I think a 40 is a slam dunk. I think a 42 is possible with a little massaging. Yup, I’ve got a rotary tool or two. And torches and welders and grinders, oh my! This is going on an aluminum lcg configuration chassis, so I have leeway to coax things into place while still maintaining integrity.
I’m pretty sure that;
A: It’s going to be awesome,
B: I’m going to use foul language when things don’t work out as planned,
C: I’m going to give “foul language” a whole new definition when I finally run a 4s pack through it, and,
D: It’s going to be awesome.
I‘ll definitely start a build thread so anyone who doesn’t have anything better to do can follow this ill advised endeavor to the bitter end. But for the moment I’ll stand on A and D. It’s going to be awesome! (Or something.)
 
I've put all of these in my HCG slash chassis, but I did have to grind a little bit for the rear end of the motor to have clearance.
Hobbystar 3665 3100kv: https://www.rcjuice.com/hobbystar-3665-4-pole-brushless-sensorless-motor-waterproof.html

HPI Tork 2200kv: https://www.hpiracing.com/en/part/100685
- had to cut/grind some of the side fins off that one, they stuck out too far.

Traxxas 2200kv: https://traxxas.com/products/parts/motor/3376waterproof2200motor

Current:
Arrma blx4074: https://www.arrma-rc.com/part/AR390205

Anyone know if the LCG chassis is narrower than the HCG chassis? looking at photo's, it kind of looks narrower.
 
I've put all of these in my HCG slash chassis, but I did have to grind a little bit for the rear end of the motor to have clearance.
Hobbystar 3665 3100kv: https://www.rcjuice.com/hobbystar-3665-4-pole-brushless-sensorless-motor-waterproof.html

HPI Tork 2200kv: https://www.hpiracing.com/en/part/100685
- had to cut/grind some of the side fins off that one, they stuck out too far.

Traxxas 2200kv: https://traxxas.com/products/parts/motor/3376waterproof2200motor

Current:
Arrma blx4074: https://www.arrma-rc.com/part/AR390205

Anyone know if the LCG chassis is narrower than the HCG chassis? looking at photo's, it kind of looks narrower.
I think you might be talking about a 2wd/RWD? If it’s 4x4, the Arrma 4074 fit ok?
 
I think you might be talking about a 2wd/RWD? If it’s 4x4, the Arrma 4074 fit ok?
It's 4x4. I had to grind a little out of the chassis, but it fit ok in the slash 4x4 hcg chassis. With the stampede chassis, there wasn't enough room unless I relocated the esc or something. Instead, I used the stampede receiver box in the stampede location behind the front tower which left me a lot of room for whatever I wanted.
2022-0101-stampede-gpmBulks-side-frontHigh-electronics.jpg
 
Not harsh at all, I appreciate knowledgeable feedback even if it differs with my current vision. That’s why I’m here! We can’t always imagine every consideration/downside to a plan, so I appreciate everyone’s take on this, especially to those with prior experience relative to the initial question. I broke out the caliper and I think a 40 is a slam dunk. I think a 42 is possible with a little massaging. Yup, I’ve got a rotary tool or two. And torches and welders and grinders, oh my! This is going on an aluminum lcg configuration chassis, so I have leeway to coax things into place while still maintaining integrity.
I’m pretty sure that;
A: It’s going to be awesome,
B: I’m going to use foul language when things don’t work out as planned,
C: I’m going to give “foul language” a whole new definition when I finally run a 4s pack through it, and,
D: It’s going to be awesome.
I‘ll definitely start a build thread so anyone who doesn’t have anything better to do can follow this ill advised endeavor to the bitter end. But for the moment I’ll stand on A and D. It’s going to be awesome! (Or something.)
Ok, phew! Yeah, I often overlook things when I do mods! I got a new rotary tool from one of my friends 3 weeks ago, it's not Dremel brand, but it works well! I've always wanted a rotary tool, and I told my friend that, then a few days later, it showed up at my door, to my complete surprise and excitement (it was like a late B-day and Christmas gift)!

It's definitely going to be awesome! There will probably be a few rage moments though...we all have them! Good luck!
 
As the owner of a Slash VXL (LCG chassis) 4x4, I can tell you that they are part plane. Anytime there is bit of wind, bump in the road or you get over ~45MPH it likely to take to the air in stock form. So a bigger motor won't make it faster.

If you want to go faster plan on some chassis, suspension and tire mods along with new body. See Kaizer Test links below.

El Sob on the Traxxas forums and Youtube has a good combination. You can read about it here.
https://forums.traxxas.com/discussi...hat-motor-and-esc-should-i-buy-quot-thread/p1

KaizerTest RC on Youtube has a recipe for 100 MPH+ in the comments of this Youtube Video you will see his recipes.
One key thing he uses is a different motor mount.
https://www.sagacustomrc.com/store/..._motor_mount(jess34753)_LCG_chassis_only.html

Best of luck and post video when your done.
 
As the owner of a Slash VXL (LCG chassis) 4x4, I can tell you that they are part plane. Anytime there is bit of wind, bump in the road or you get over ~45MPH it likely to take to the air in stock form. So a bigger motor won't make it faster.

If you want to go faster plan on some chassis, suspension and tire mods along with new body. See Kaizer Test links below.

El Sob on the Traxxas forums and Youtube has a good combination. You can read about it here.
https://forums.traxxas.com/discussi...hat-motor-and-esc-should-i-buy-quot-thread/p1

KaizerTest RC on Youtube has a recipe for 100 MPH+ in the comments of this Youtube Video you will see his recipes.
One key thing he uses is a different motor mount.
https://www.sagacustomrc.com/store/p30/Rally/slash_4x4_lcg_motor_mount(jess34753)_LCG_chassis_only.html

Best of luck and post video when your done.
Yeah, I have a couple Slash 4x4’s and 2wd’s, and the combination of the chassis and the SCT bodies blow over (and parachute) worse than any other truck I think I’ve ever messed with.
I found a motor mount I think I can adapt for a 42mm can and that will be plenty.
l’ve been hip to the El Sob mods for awhile, some are great and some I’d take a different approach to. I’ll check out the other link, never seen KaizerTest, thanks for that.
This build will be “Slash based” because of the chassis and parts availability for that platform, but there ain’t going to be many Traxxas parts left in the final build.
When I start I will post a build thread.
 
As the owner of a Slash VXL (LCG chassis) 4x4, I can tell you that they are part plane. Anytime there is bit of wind, bump in the road or you get over ~45MPH it likely to take to the air in stock form. So a bigger motor won't make it faster.

If you want to go faster plan on some chassis, suspension and tire mods along with new body. See Kaizer Test links below.

El Sob on the Traxxas forums and Youtube has a good combination. You can read about it here.
https://forums.traxxas.com/discussi...hat-motor-and-esc-should-i-buy-quot-thread/p1

KaizerTest RC on Youtube has a recipe for 100 MPH+ in the comments of this Youtube Video you will see his recipes.
One key thing he uses is a different motor mount.
https://www.sagacustomrc.com/store/p30/Rally/slash_4x4_lcg_motor_mount(jess34753)_LCG_chassis_only.html

Best of luck and post video when your done.
Yeah, I have a couple Slash 4x4’s and 2wd’s, and the combination of the chassis and the SCT bodies blow over (and parachute) worse than any other truck I think I’ve ever messed with.
I found a motor mount I think I can adapt for a 42mm can and that will be plenty.
l’ve been hip to the El Sob mods for awhile, some are great and some I’d take a different approach to. I’ll check out the other link, never seen KaizerTest, thanks for that.
This build will be “Slash based” because of the chassis and parts availability for that platform, but there ain’t going to be many Traxxas parts left in the final build.
When I start I will post a build thread.
I would imagine that they don't have very good high speed control, stock. Probably as the big SCT chassis acts like a huge wing, so when you accelerate, the rear end goes down, front end comes up (easy physics!), and then you have a ton of surface area to create lift. This could probably helped by adjusting the suspension to a "speed run" style, which is to say, when the truck is stationary, with the battery in, the front end of the chassis is a little lower than the rear, so when you accelerate, the chassis is about level, instead of leaning back, creating lift. And as you said, the body is gonna have to be one of the first mods, I haven't driven and SCT before, but in videos, I can see that "parachuting" effect, and they blow over, catch wind, and handle jumps badly, especially bigger ones, and the moment the nose goes up and air gets in, your air control pretty much goes out the window! Some people like to "vent" their bodies, as you know. Basically drilling and/or cutting holes and slits in smart places to let some air come out. If done right, it'll handle better, but you'll always have a "little parachuting".

I'm wondering if a front splitter/wing would help to with some front-end downforce, as on the Slash/Bandit/Rustler, there's significant "backsweep" (for lack of a better term) on the front A-arms, so the front arms can act like mini wings too, if there's enough surface area on the bottom of the front A-arms. Traxxas tried that idea here, the front splitter didn't really help much, but food for thought! A wheelie bar would also help, I'm thinking a short wheelie bar, or none at all, for street ripping, and a long, drag style on for those crazy 6s speed runs.
 
I would imagine that they don't have very good high speed control, stock. Probably as the big SCT chassis acts like a huge wing, so when you accelerate, the rear end goes down, front end comes up (easy physics!), and then you have a ton of surface area to create lift. This could probably helped by adjusting the suspension to a "speed run" style, which is to say, when the truck is stationary, with the battery in, the front end of the chassis is a little lower than the rear, so when you accelerate, the chassis is about level, instead of leaning back, creating lift. And as you said, the body is gonna have to be one of the first mods, I haven't driven and SCT before, but in videos, I can see that "parachuting" effect, and they blow over, catch wind, and handle jumps badly, especially bigger ones, and the moment the nose goes up and air gets in, your air control pretty much goes out the window! Some people like to "vent" their bodies, as you know. Basically drilling and/or cutting holes and slits in smart places to let some air come out. If done right, it'll handle better, but you'll always have a "little parachuting".

I'm wondering if a front splitter/wing would help to with some front-end downforce, as on the Slash/Bandit/Rustler, there's significant "backsweep" (for lack of a better term) on the front A-arms, so the front arms can act like mini wings too, if there's enough surface area on the bottom of the front A-arms. Traxxas tried that idea here, the front splitter didn't really help much, but food for thought! A wheelie bar would also help, I'm thinking a short wheelie bar, or none at all, for street ripping, and a long, drag style on for those crazy 6s speed runs.
Yes, there will be no semblance of an SCT truck. Already have a foam internal bumper and front splitter. This will be be a total road car, lowered a lot, with hopefully decent ground effects. I’ve had one of my Slash 2wd’s to 67mph and it was horrible. Total nail biter. One of my 4x4’s saw 76, also terrible. No blow-overs, but essentially uncontrollable. Super hard to keep in a straight line, especially the 2wd.
 
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