Deathvirus Powerstroke/Pro-spec Bomber

[DeathVirus]

GPS'd Top speed first/second gear: 11.7mph/20.3mph
Theoretical Top Speed: 11.15/20.65mph
Calculated Motor Power: 945 watts (1.3hp)
Calculated Axle Torque: 9.84/5.31ft-lbs
Rollout: .31:1/.58:1

Power plant: I decided to go with a Sensorless system with the 2speed kit even though it costs about the same as a sensored system. It gives you two benefits- the higher ratio in low gear combined with underdrive gears vastly reduces torque twist and the higher ratio in low gear also naturally gives more drag brake. Also makes the battery run longer when I just want to go slow. Combined with high motor timing I can punch the throttle and take off in a straight line. I still get 45mins running hard at the park too

Suspension: people normally go powerstroke or pro-spec but I went with both for two reasons- most of the Bomber’s weight is up front. With a dual stage spring it helps it run smooth in the rough stuff. Since their’s no front sway bar, the secondary spring assists in stiffening it up to keep from traction rolling on fast corners. I also run a stiffer front suspension than I do in the rear just like I would any other RC vehicle I have. I like the Pro-specs in the rear since it’s linear (more consistent traction and handling) and performs better than the stock “king” shocks.
Less donkey kick and more suspension action

Tires, wheels and foam: I really love the Proline Hyrax 2.2’s for the terrain I drive on (mostly grass, some gravel and hard packed dirt). I recently swapped from stock foams to the Proline dual stage foams. Though they’re firm I like that I can go faster without traction rolling while they still conform for grip.
I went with Gear Head front wheels to add a little weight to the front and Proline faultines in the rear for less weight. To even out the offset I added Integy wideners to the rear to give it a Yeti width of 12.4” front and 12.25” rear.

Upcoming upgrades: aluminum steering links and suspension links. I’ll upgrade those as needed.

RR10 Bomber
13/64 gearing with stock 5.67 internal ratio
Axial HD UD gears 43/13 gives it 6.417 internal ratio
Castle Sidewinder 3 with Vanguard 3150 motor
XT60 connector
Passive cooling: (2) Bastens aluminum heatsink
Savox sw-1210sg (277.7oz/in, .15s)
Castle 10A BEC enclosed in TRX receiver case for waterproofing
Axial aluminum servo horn
Axial 2spd kit with regular 2:1/1.08 gearing
Traxxas 2075 shifting servo (125oz/in, .17s)
Front shocks outboarded on bottom links
Front: Powerstroke green/blue(2.1/3.5lb-in)
Rear: Pro-spec stock yellow 2.4lb/in
Front/Rear Shock oil: 20wt/30wt
Anti-squat upper arm setting in rear
Axial "soft" Rear sway bar
Removed rear spare tire and housing
Slipper clutch 1/2 turn out
Proline 2.2 Hyrax G8 compound tires
Proline dual stage foams
Front: Gear Head 2.2 CAC Ez-Loc Aluminum BL ring with Gear Head 6-lug Plus .500 Hubs
Rear: Proline 2.2 Faultline wheels
Rear: Integy +12mm offset
TSS Brass Knuckles 1.6oz each
1oz lead weight on top of steering servo
1oz wrapped around each end of front axle
1.25oz wrapped around each end of rear axle
Tactic TTX300 transmitter
Energizer Ultimate Lithium in transmitter
Steering dual rate: reduced by 2 notches
Sidewinder ESC Setting: 1.Forward/brake/Reverse, 2.Brakes 25%, 3.Reverse speed 75%, 4.Punch control level 1.High, 5.Drag brake 10%, 6.Dead Band Normal(.1ms), 7.Voltage cutoff Auto, 8.Motor timing High(10-20 degrees), 9.Motor type Brushless
Gens Ace 3s 5000mah 50c "short" pack XT60
Front/Rear Ride Height: 1.73"/1.89" (measured at pumpkin to ground)
Front/Rear track width: 12.4"/12.25"

No interior for the most part. It gets hot down here in Louisiana but I can always add it back on

Wide stance like the Yeti

I love how the suspension works

Low gear

High gear

Running temps- ESC stays under 135F, motor under 110F, battery 81F if I run it hard 20min+

Videos coming soon

 

[Crawler Cads]

Subbed, get some media up here!!! Sounds great.

Sent from my Pixel using Tapatalk

 

[DeathVirus]

And there you have it. Videos coming soon hopefully. I’d like to get some running videos in different types of terrain to show how it performs. It’s much better than it was and exponentially better than stock. I can go faster in the turns and I can go faster over the bumps.

 

[Brake Weight]

Are you North or South LA?

 

[DeathVirus]

Are you North or South LA?

South but not the dirty south 8)

 

[Brake Weight]

South but not the dirty south 8)

Lol. Just above i10 then? I’ve been troo dere enough, yeah.

 

[DeathVirus]

Lol. Just above i10 then? I’ve been troo dere enough, yeah.

Yea choot em

 

[Brake Weight]

Yea choot em

I miss working with those guys from time to time...and the white rubber boots.

I like the wide stance but it hinders it when trying to crawl anything. PlastiDip works good to cover up the stock panels. I cut some out of lexan I ordered off of fleaBay and painted them.

 

[DeathVirus]

I miss working with those guys from time to time...and the white rubber boots.

I like the wide stance but it hinders it when trying to crawl anything. PlastiDip works good to cover up the stock panels. I cut some out of lexan I ordered off of fleaBay and painted them.

Nice in Russian red. What you running?

I work for the railroad as freight train conductor. Some of the best places to run are by the yard with their nice sized rocks but I haven’t done it yet.

I like the wide stance to go fast. I’ve always liked going fast. I’ve always built versatile machines for going fast and trails. I’m not too big on scale crawling. It looks interesting and maybe one day I’ll have a purpose-built crawler but for the most part I just like the U4RC style. I can make my bomber go faster but it’s not as stable over bumps as an IFS would be

 

[Brake Weight]

Nice in Russian red. What you running?

I work for the railroad as freight train conductor. Some of the best places to run are by the yard with their nice sized rocks but I haven’t done it yet.

I like the wide stance to go fast. I’ve always liked going fast. I’ve always built versatile machines for going fast and trails. I’m not too big on scale crawling. It looks interesting and maybe one day I’ll have a purpose-built crawler but for the most part I just like the U4RC style. I can make my bomber go faster but it’s not as stable over bumps as an IFS would be

A big 40mm Chinese sensorless and a 4s SCT ESC. I put an open diff from an SMT monster truck and would recommend getting one if you don’t crawl any.

 

[DeathVirus]

A big 40mm Chinese sensorless and a 4s SCT ESC. I put an open diff from an SMT monster truck and would recommend getting one if you don’t crawl any.

I like the locked diffs for trails. Helps getting over steep ledges and big tree roots

 

[durok]

I've got a set of those wheels (Gearhead CAC) you're using up front - some of the best you can buy!

Looks like you're havin' some serious fun with your Bomber!

 

[DeathVirus]

I've got a set of those wheels (Gearhead CAC) you're using up front - some of the best you can buy!

Looks like you're havin' some serious fun with your Bomber!

It’s a ton of fun. Very versatile. I also have a Traxxas Summit which has similar performance but is slower and not scale so not as challenging and not as fun. For street running I have a 57mph Arrma Kraton that can run full charge without overheating. My twin boys have a Traxxas Skully 4x4 and Rustler 4x4 (both based off heavily modded Stampede 4x4’s) and they both run 28 and 30mph while being versatile enough to also hit the trails. Since I no longer have a truck I like just bringing 1 RC per person in our little SUV so having versatile RC’s makes hauling easier

I like the wheels a lot. Easier to use than Proline wheels and adds a little weight. It was a good value

 

[DeathVirus]

IntrepidMercians calculated the Axial “soft” sway bar’s stiffness to equal .455n/mm.
That translates to 4.027 lb/in which is pretty substantial.

Most RC’s benefit from a stiffer front end to counter traction rolling which is probably why the Traxxas X-Maxx is much wider in the front than the rear. 1/10 buggies are narrower in front but they also have narrow front wheels to reduce front traction. After watching what causes the Bomber to traction roll by trying to force it traction roll over and over I found that it depends a lot on the rear rather than the front! That’s probably why Axial made their sway bars so stiff for the Bomber. This is also probably why my Bomber made such a huge improvement in traction roll reduction when I made the rear wider

I plan on buying an Axial Yeti or Losi Rock Rey or both sometime this month to experiment with

 

[durok]

IntrepidMercians calculated the Axial “soft” sway bar’s stiffness to equal .455n/mm.
That translates to 4.027 lb/in which is pretty substantial.

Most RC’s benefit from a stiffer front end to counter traction rolling which is probably why the Traxxas X-Maxx is much wider in the front than the rear. 1/10 buggies are narrower in front but they also have narrow front wheels to reduce front traction. After watching what causes the Bomber to traction roll by trying to force it traction roll over and over I found that it depends a lot on the rear rather than the front! That’s probably why Axial made their sway bars so stiff for the Bomber. This is also probably why my Bomber made such a huge improvement in traction roll reduction when I made the rear wider

I plan on buying an Axial Yeti or Losi Rock Rey or both sometime this month to experiment with

You can also gain some extra width by flipping the hubs around on Gearhead wheels - it changes the offset. Good for experimentation!

 

[DeathVirus]

You can also gain some extra width by flipping the hubs around on Gearhead wheels - it changes the offset. Good for experimentation!

Yea I’ve done that already. I had to double check to make sure I already did it. It’s been a while

 

[DeathVirus]

Ok I bought an Axial Yeti for one of my sons. Only thing I’ve done so far was change the oil to 60wt/30wt and mess with the ESC settings. . It drives so smooth and quiet and it seems so much more agile. I have Proline Badlands 2.8’s on it right now until the Hyrax 2.2’s come in the mail. Once they arrive I’ll put the Proline Single stage foams in them, change the front/rear bevel gears to the HD 43/13, change the front diff oil to either 500k or 1M, and possibly drop the pinion a tooth.

I think I’m just used to driving IFS. It traction rolls much less than solid axles even with the grippier Badlands on the grass. The ESC got hot when I ran the stock tires on it in the grass so that’s why I was thinking of dropping the pinion a tooth. Stock rollout is .76. With the setup I’m gona go with it’ll be .71. If I drop the pinion down it’ll be .67. We’ll see how hot it gets before I change the pinion I suppose

 

[DeathVirus]

I don’t know how to upload videos on here but my suspension combination has been fantastic. The only gripe I have with the Pro-specs is that I’m not used to bleeding them so it was harder for me to fill up than the Powerstroke. I might end up just getting Powerstrokes for the front and rear of each of my sons’ Yeti and Rock Rey

 

[DeathVirus]

I have been thinking about going up a pinion tooth to get a little more speed out of it now that I’m used to solid axle. The problem is the way it is now my ESC will sometimes hit ~130F. My motor will 130F too sometimes as well (110F when it was “low timing.”) and I already have it set to “high” timing on the Sidewinder 3. I really don’t want to put a fan on the ESC as I’ve done in the past with previous builds because I run mostly in grass and it can get pretty dirty.

Currently running 13/64 with the 43/13 bevel gears, 2.2” Hyraxes, 1.08 2nd gear, and a CC BEC.

 

[durok]

Running in grass is why you're getting higher temps... the ESC and motor are having to fight the added resistance to forward motion.