Losi Baja Rey 1/10th 4WD RTR desert truck

[BobTeagle]

Originally Posted by crawlingman9000

https://www.youtube.com/watch?v=uSw8H-HfjNQ this thing might be 4x4 sct class race worthy... with a good servo and horn... maaaaan! cant wait till they come out with the clear panels!

The clear panels are available. Just got mine today from Vortex Hobbies and will be painting up my own soon!

[CM9000]

sweet dude. now I gotta get a set or two ordered for the hobby shop. ill be getting mine next Wednesday then...

[CM9000]

https://www.youtube.com/watch?v=uSw8H-HfjNQ

dude! freakin had me goin.

[ser3100]

Gonna bash both today to see how they do against each other. Was supposed to earlier in the week but we all know how family life goes!

[BobTeagle]

Painted up a new body for the Rey today!







[IMG]
http://i1060.photobucket.com/albums/t450/kxt6569/IMG_1501_zpseolcuaek.jpg[/IMG]

[ser3100]

Dude that paint scheme is so much cleaner and nicer than both stock offerings

[GLHS592]

I saw this the day they announced it, but forgot about it until today. I have been on and off about getting a Yeti Score. I've watched a few videos and the Baja Rey has run over that fence. I think my wife should buy me one for Christmas.

[fyrstormer]

The Baja Rey handles immensely better than the Yeti Score. Save yourself the pain and get the Baja Rey to start with.

In case nobody's posted it yet, here are the 12 screws you have to remove to take off the Baja Rey's rollcage and body in one piece:





Also, for the record, I put filled the center diff completely with 10K oil, and left the front diff completely open -- just a bit of marine grease to lube the gears. That way the rear axle can get a decent amount of power on hard accelerations, without the front axle spinning like crazy, and the truck can also climb diagonally over curbs now, but if it corners too hard the inside-front wheel can still diff-out easily to unload excess torque. I fiddled with the tires and suspension and ended up putting them back to stock; this is one exceptionally well-dialed-in vehicle right out of the box.

[ser3100]

So much easier removing the body the way you did

[BobTeagle]

Originally Posted by fyrstormer

The Baja Rey handles immensely better than the Yeti Score. Save yourself the pain and get the Baja Rey to start with.

In case nobody's posted it yet, here's how to remove the body/rollcage from the Baja Rey's chassis in one piece, so you can access the drivetrain and electronics (relatively) easily:

In case nobody's posted it yet, here are the 12 screws you have to remove to take off the Baja Rey's rollcage and body in one piece:





Also, for the record, I put filled the center diff completely with 10K oil, and left the front diff completely open -- just a bit of marine grease to lube the gears. That way the rear axle can get a decent amount of power on hard accelerations, without the front axle spinning like crazy, and the truck can also climb diagonally over curbs now, but if it corners too hard the inside-front wheel can still diff-out easily to unload excess torque. I fiddled with the tires and suspension and ended up putting them back to stock; this is one exceptionally well-dialed-in vehicle right out of the box.

I agree 100% with the Baja Reys handling!! Ive spent weeks tuning and upgrading my Yeti Score Kit and was amazed at how the Baja Rey handled out of the box! After just a servo upgrade and lowering the pinion to the optional 10tooth for 3s I am sold on this beast! I will say that Axial still has a chance if they release a center diff to replace the locked center output gear in the transfer case. I think the Rey has better suspension geometry as well, but the center diff is the main reason it handles so well! when throttleing on corners the center diff allows the power to transfer to the front end and pull it through the turn! Take the Axial Score around the same corner with the same throttle and it will spin out. I still like the Axial Score, but Losi has improved the formula. Now, lets cross our fingers for Traxxas and Associated to get on board!

[fyrstormer]

Originally Posted by ser3100

So much easier removing the body the way you did

Glad I could help. I wanted to get the info out there before the myth that the rollcage has to be disassembled becomes too widespread.

Originally Posted by BobTeagle

I agree 100% with the Baja Reys handling!! Ive spent weeks tuning and upgrading my Yeti Score Kit and was amazed at how the Baja Rey handled out of the box! After just a servo upgrade and lowering the pinion to the optional 10tooth for 3s I am sold on this beast! I will say that Axial still has a chance if they release a center diff to replace the locked center output gear in the transfer case. I think the Rey has better suspension geometry as well, but the center diff is the main reason it handles so well! when throttleing on corners the center diff allows the power to transfer to the front end and pull it through the turn! Take the Axial Score around the same corner with the same throttle and it will spin out. I still like the Axial Score, but Losi has improved the formula. Now, lets cross our fingers for Traxxas and Associated to get on board!

A locked center diff would allow torque to transfer to the front axle more efficiently, actually -- it would force the front and rear axles to share the torque 50/50 at all times -- but that's part of the problem. After trying multiple configurations with my Yeti and Twin Hammers, I realized that solid-rear-axle trucks just don't work right unless the rear axle is locked, because otherwise you get horrible torque-steer every time the chassis twists when accelerating. That severely limits drivetrain-tuning options.

So, with a truck that has a locked rear diff AND a locked center diff, like the Yeti, there is no escape path for excess torque unless both rear wheels come off the ground. (i.e., when the truck is in the air, in which case handling isn't really a concern anyway.) That means, even if the truck corners so hard that the inside wheels come off the ground, the motor can continue driving the truck into the corner, because the locked rear axle is constantly transferring power to the outside-rear wheel, and the locked center diff is ensuring that the front axle can't "diff-out" by spinning faster than the rear axle.

You can see what I mean by lifting up one side of your Yeti and trying to rotate the front wheel that's in the air -- despite being connected to an open diff, it still will force all four wheels to rotate, because the rear axle is locked and the front axle is forced to rotate at the same speed as the rear axle. My Yeti and Twin Hammers were both impossible to drive on pavement, and difficult to drive on grass, without nearly-constant traction-rolling because their motors could drive the trucks into corners so hard they simply rolled over. It was so frustrating I actually entertained the fantasy of driving my Twin Hammers into a curb at top speed just to watch it smash to pieces. (I sold it instead.)

In that same hard-cornering scenario with an unlocked center diff, when the inside wheels start to come off the ground, the center diff and front diff combine to give the inside-front wheel the freedom of movement to diff-out and release the torque from the motor. That means the motor can't keep driving the truck into the corner once the inside-front wheel starts to lift. Of course, having a completely open center diff would mean the rear axle would struggle to get any power from the motor when accelerating, because both front wheels would start to diff-out as soon as the truck leaned backward a bit, and that's exactly what the Baja Rey does out of the box; that's why I filled the center diff with 10K oil, to make it easier for the rear axle to get its share of the motor's torque, without making it too difficult for the inside-front wheel to diff-out in corners. It works marvelously with this setup; it can now climb diagonally over curbs, it can accelerate better because the rear axle can get more torque when accelerating, it can brake harder because the front axle can get more torque when braking, but it can still diff-out when cornering. If I were driving on looser terrain I might want 30K oil in the center diff instead, but I think in all cases that don't involve rock-crawling this truck benefits greatly from a completely open front diff. (and if you're rock-crawling, why are you using a trophy truck?)

The Yeti would benefit greatly from a center diff (does the one from the EXO fit, by any chance?), but the Baja Rey will still have a center-of-gravity advantage. In the Baja Rey, the battery and motor are both sitting right on the chassis plate, whereas in the Yeti they are both above the chassis plate by as much as an inch. Short of someone making a custom chassis AND gearbox for the Yeti, the Baja Rey will always be more stable because of its design. It also helps that Losi nailed the rear-suspension design, with the lower links connecting below the axle, giving the links lots of leverage to prevent axle twist, without needing tons of clearance above the axle for super-high upper links. The shock placement is perfect too; the rear shocks are so close to the rear wall of the chassis tub that even the small amount of sprung-weight above the rear axle is enough to give the rear shocks something to act against, so the rear suspension actually responds to bumps instead of tail-hopping all over the place.

The Baja Rey is much more of a scale-accurate, solid-rear-axle trophy truck (basically what RC short course trucks were supposed to be all along), rather than a fast rock-crawler like the Yeti, and that's fine with me. I tried for months to get my Yeti, and then my Twin Hammers, to be what the Baja Rey is; I wish I'd waited a year and bought this instead, I would've saved a LOT of money.

[CM9000]

^ yep. besides me owning a yeti part...

my Baja rey stripped the servo horn in 7 minutes around a track. servo was to slow for me anyway. swapped out for a decent savox.

if you want to run a connector other than ec3... its sad news but you need to throw the interior out. traxxas wont work and neither will deans. deans maybe. but id imagine after so many runs the deans will fall out on a hard landing.

[fyrstormer]

I haven't gotten around to changing the battery plug yet, but my plan is to just remove the integrated plug and have an XT90 plug sticking out through the hole. The integrated plug should be easy enough to remove, there's only two screws holding it in-place.

[CM9000]

you don't want a plug hanging any farther than the ec3 connector already is. trust me.

[ser3100]

Great input frystormer! LIke you, having both, really puts it into perspective where the yeti is compared to the baja rey. LIke many have stated, this truck is doing what its doing with the only mods bieng a better servo or servo horn, cooling fan, and diff fluid. Imagine what it could do if and when the aftermarket jumps aboard. I cant wait! Im seriously thinking of unloading my yeti but ill give it a few more chances. A FEW!

On a side note im a little dissapointed in both Vanquish and MIP. I emailed them both and got pretty much the same response. "Thank you for input. Im not sure what the status is for that truck"

Maybe its too new, who knows, but for a truck that works pretty good box stock i think its possibilities are pretty high.

[ser3100]

@frystormer

YOu mentioned that you have the twin hammers truck as well? Is there any chance of measuring the driveshaft length of the TH? Im trying to see if it would be the same length as the Reys. If it is, MIP is discontinuing thier C drive kits for the TH. Cheap, but its gotta fit first. Any chance of checking the specs? Thanks

[BobTeagle]

Originally Posted by fyrstormer

Glad I could help. I wanted to get the info out there before the myth that the rollcage has to be disassembled becomes too widespread.

A locked center diff would allow torque to transfer to the front axle more efficiently, actually -- it would force the front and rear axles to share the torque 50/50 at all times -- but that's part of the problem. After trying multiple configurations with my Yeti and Twin Hammers, I realized that solid-rear-axle trucks just don't work right unless the rear axle is locked, because otherwise you get horrible torque-steer every time the chassis twists when accelerating. That severely limits drivetrain-tuning options.

So, with a truck that has a locked rear diff AND a locked center diff, like the Yeti, there is no escape path for excess torque unless both rear wheels come off the ground. (i.e., when the truck is in the air, in which case handling isn't really a concern anyway.) That means, even if the truck corners so hard that the inside wheels come off the ground, the motor can continue driving the truck into the corner, because the locked rear axle is constantly transferring power to the outside-rear wheel, and the locked center diff is ensuring that the front axle can't "diff-out" by spinning faster than the rear axle.

You can see what I mean by lifting up one side of your Yeti and trying to rotate the front wheel that's in the air -- despite being connected to an open diff, it still will force all four wheels to rotate, because the rear axle is locked and the front axle is forced to rotate at the same speed as the rear axle. My Yeti and Twin Hammers were both impossible to drive on pavement, and difficult to drive on grass, without nearly-constant traction-rolling because their motors could drive the trucks into corners so hard they simply rolled over. It was so frustrating I actually entertained the fantasy of driving my Twin Hammers into a curb at top speed just to watch it smash to pieces. (I sold it instead.)

In that same hard-cornering scenario with an unlocked center diff, when the inside wheels start to come off the ground, the center diff and front diff combine to give the inside-front wheel the freedom of movement to diff-out and release the torque from the motor. That means the motor can't keep driving the truck into the corner once the inside-front wheel starts to lift. Of course, having a completely open center diff would mean the rear axle would struggle to get any power from the motor when accelerating, because both front wheels would start to diff-out as soon as the truck leaned backward a bit, and that's exactly what the Baja Rey does out of the box; that's why I filled the center diff with 10K oil, to make it easier for the rear axle to get its share of the motor's torque, without making it too difficult for the inside-front wheel to diff-out in corners. It works marvelously with this setup; it can now climb diagonally over curbs, it can accelerate better because the rear axle can get more torque when accelerating, it can brake harder because the front axle can get more torque when braking, but it can still diff-out when cornering. If I were driving on looser terrain I might want 30K oil in the center diff instead, but I think in all cases that don't involve rock-crawling this truck benefits greatly from a completely open front diff. (and if you're rock-crawling, why are you using a trophy truck?)

The Yeti would benefit greatly from a center diff (does the one from the EXO fit, by any chance?), but the Baja Rey will still have a center-of-gravity advantage. In the Baja Rey, the battery and motor are both sitting right on the chassis plate, whereas in the Yeti they are both above the chassis plate by as much as an inch. Short of someone making a custom chassis AND gearbox for the Yeti, the Baja Rey will always be more stable because of its design. It also helps that Losi nailed the rear-suspension design, with the lower links connecting below the axle, giving the links lots of leverage to prevent axle twist, without needing tons of clearance above the axle for super-high upper links. The shock placement is perfect too; the rear shocks are so close to the rear wall of the chassis tub that even the small amount of sprung-weight above the rear axle is enough to give the rear shocks something to act against, so the rear suspension actually responds to bumps instead of tail-hopping all over the place.

The Baja Rey is much more of a scale-accurate, solid-rear-axle trophy truck (basically what RC short course trucks were supposed to be all along), rather than a fast rock-crawler like the Yeti, and that's fine with me. I tried for months to get my Yeti, and then my Twin Hammers, to be what the Baja Rey is; I wish I'd waited a year and bought this instead, I would've saved a LOT of money.

lol! Much of what you are saying is a more technical version of what I said. You my friend have more patience with a keyboard than I do😋

I haven't taken my tranny down yet to see what's in the center diff yet, but I'm pretty happy with it so far. Even with grease I'm getting plenty of power to the rear. It shocked me because grease in a center diff usually means having front wheel drive lol. I may pull my tranny soon to add diff fluid.

My axial score is actually doing quite well with its current tuning. I have 10k in the front diff, 80wt in front shocks, and 40wt in the rear shocks. 24tooth pinion and 56t spur on 3s with 3100kv motor. I also added weight down low on the rear with super shafty steel lower links, incision steel upper links, and a wide centered SSD axle. With this set up it is fast and nimble. Keep in mind I have added some aluminum here and there so it is heavier than stock. I still give the Baja Rey a nod for better handling though. The EXO diff would not work w/out removing the entire center tranny and motor mount and replacing with the EXO center diff / motor mount. That is more modification than I'm willing to do. Axial could easily make a center diff that would be a drop in where the center output gear is located in the transfer case. I'm trying to keep faith in the Yeti Score because we need more than one trophy truck if we plan on seeing the class grow.

Here is an overview of my setup.

https://youtu.be/v8_KEjl96QQ

[fyrstormer]

Originally Posted by ser3100

@frystormer

YOu mentioned that you have the twin hammers truck as well? Is there any chance of measuring the driveshaft length of the TH? Im trying to see if it would be the same length as the Reys. If it is, MIP is discontinuing thier C drive kits for the TH. Cheap, but its gotta fit first. Any chance of checking the specs? Thanks

Sorry, I don't have it anymore.

[fyrstormer]

I've seen several people complaining about grit getting into the center gearbox. I noticed a bit sneaking into mine as well. Based on what I saw when I dug into the center gearbox, the most likely entry point is the un-sealed area covered by the trap-door used to access the motor. I have a ton of miscellaneous Tamiya parts handy, from all those XV-01s I built, so I dug out a piece of soft adhesive foam padding and made a seal for that part of the trap-door. This should stop grit from sneaking in when the slide-out motor mount wiggles around inside the gearbox bulkhead. It might not be a 100% solution, but currently that area has no seal at all, so it will definitely be an improvement.

[ser3100]

Great idea thanks!