Manta Ray - 2019 Vonats Build

[scr8p]

I never thought I would happen to win one of the big Vonats door prizes. Well, this year I did just that. Walked out with a new Tamiya Manta Ray kit. So now, instead of struggling with a rc10 on old tires, I'll get to go balls out with 4wd and modern rubber.

[NomadRacer]

Wow, you lucky man!

[TRX-1-3]

That's rad. Keep the balls in though.

[DennisM]

Best looking 1:10 buggy body EVER!

[Asso_man!]

You finally own a high performance off road racer! Congrats for being so patient

[Headling]

Cool! Should be a good build

[tamiyadan]

.

[stickboy007]

You can't upgrade to a carbon chassis for the Classic class (must keep the plastic tub), but that's no big deal. All I really did to mine was add the aluminum motor mount and a heatsink. I have some other bits on there to try to reduce weight (titanium screws, aluminum kingpins, hollow carbon shafts in the gearbox, etc.), but I can't say it made a noticeable difference. I mean, maybe it did, but the car felt the same. I also opted not to use the hardened center prop shaft (stuck with the stock floppy one), as it's a little heavier.

I have ball diffs front and rear on mine, but the gear diffs are definitely more reliable (although heavier) and is probably why the kit puts a gear diff in the back (that's where the splines will strip first). You should be able to get one full, hard race weekend out of the ball diffs before the splines start to go on you. If anything, just pick up the hardened diff outputs and use some thick grease on the splines. I've been running the stock splines to-date, but will use the hardened ones going forward. The Sport Tuned motor isn't really going to kill anything. I have no idea how Raul managed to destroy his brand new ball diffs at VONATS. Maybe the re-re units have the splines cut a little differently (more shallow? I don't know), or maybe he's just a psychopath, or maybe both

As for the towers, what worked for me was to apply some JB Weld around the shock mounting posts on the towers. That should keep them from cracking or, in my case, contain the existing cracks to prevent catastrophic failure.

If you don't drive like a knob, you won't have any issues with the castor blocks, steering blocks, or rear hubs. The rear hubs are actually pretty chunky and should be pretty strong anyway. The weakest among those parts are the steering blocks, but I've had the same blocks on my car for over two years and not a single crack has shown up on them so far. The gearboxes will crack over time, but I haven't needed to replace mine yet. Some people run this silly mod where they add a brace/post between the rear gearbox cover and the rear tower, to keep the rear gearbox cover from lifting, but you'll never have that problem if you just use M3 screws instead of that self-tapping garbage. The only area where I did have a problem was in 2016, when the left side of the steering rack came out, because the screw that holds it in is one of those weird post screws and it's self-tapping (Tamiya makes a non-self-tapping version of that screw that is also coated for smoothness. I'd recommend getting a few sets of them and using them instead of the stock units). I had the servo horn set up a little too tall, and it was pulling up on the rack while turning. So...be damn sure, if you're using your own servo horn, that the link between the horn and the steering rack is as flat as possible, so that the link is only pushing left/right on the rack and not pulling up.

As for setup, I think I have 35wt or 40wt oil all around. With the stock shocks, it's pretty damn smooth and has just about the right amount of damping. I also run maximum gearing (21T pinion). I may experiment with the speed tuned gear set, but so far it hasn't been necessary.

[jwscab]

Your car looked great out there. We're you also running stock springs? I picked up one too, and was trying to figure out the rough oil wieght Tamiya provided and what I should start with. I think 35 wt was what I can up with. I was planning to run gear diffs and put some heavy grease in them

You can get some better steering racks that fit bearings from the top force tree also.

[Headling]

Thanks for the advice I’ve got a top force I want to race on the way so the mods etc will pass over to this

Are there any videos around of the vonats?? Be interested to see the manta ray racing

[stickboy007]

Thanks, jwscab. Yes, I was also running the stock springs. The RCE track is pretty high grip, so you may want to bring both 35wt and 40wt oil and see what works best. The shocks also don't leak at all. Seriously good/smooth shocks considering how they come off of a parts tree.

FWIW, I use Kyosho Lazer ZX6 wheels on mine, and they fit fine and there are no issues with wheel offset or anything like that. Maybe not exactly the same as the stock wheels, but I try to re-use wheels across platforms wherever I can, to save on tire and wheel costs.

I had forgotten to mention that the other "mod" that's very important is to ditch the aluminum idler gears in the rear gearbox. That thing sheds like a golden retriever. Just use the standard TA02 plastic gears, which are lighter and don't wear as much.

I recorded some of my runs with the Dirt Thrasher at VONATS:





I've had some form of a TA02/DF01 chassis since Christmas 1994, and it's just a really great platform with not too much to complain about (at least for a Tamiya). I'm considering also running a Top Force for the Classic 4wd class next time, as it would be great to see one out there, but we'll see. I have several cars/builds to evaluate before committing to something to replace my YZ10 in that class.

[scr8p]

So here's my car. Hop-ups include full bearings, front and rear ball diffs, hardened prop shaft, aluminum motor mount, b6 ball cups and studs, AE titanium turnbuckles, Dark Impact 2.2 wheels, Integy clamping wheel hexes, and Jconcepts Dirt Web tires.

The car worked well. I was almost a full lap behind after the first minute in the Main. But managed to get up to the front and battle for the win in the closing laps. Wound up 2nd. All in all, it was a good first outing.

[dldiaz]

Car looked awesome out there scr8p! Great race!


-dldiaz

[GoMachV]

I foresee a TRF tattoo in your future

[scr8p]

Nah.... that would conflict with my Kyosho ink.