Tamiya Durga DB01 EP Buggy (A cheaper 501X?)

[Spoolio]

Originally Posted by antnee

For those people that have changed the locknut in the diff's; Did you get the tamiya blue ones, or another make all together?

Wossa blue locknut then? I've got loads of the stock kit screws and locknuts, didn't realise there was any problem with them other than potential weakness due to the weedy size. I wouldn't have thought an anodised nut would help there at all. It really ought to be a thicker setscrew like the one off a B4 or something IF it is a problem.

More rebuilding tonight and I had crossed my fingers that my kit rear diff was going to be salvagable but only the screw, spacer, spring and thrust bearing could be reused. The diff rings have been badly scored by the balls which have in turn chewed into the pulley and the outdrives have torn into the plastic sideplates too . I didn't realise a 5.5 brushless could inflict that much damage, especially with a slipper being fitted. On the upside the front diff is like new .

[ruf]

http://www.tamiyausa.com/product/ite...oduct-id=54079

[SidewaysLS4]

I'm pretty sure I got my Durga fairly bulletproof and high-speed controllable after the last few days of running it around. Powered by a GTB/5.5r/lipo. Ceramic diff balls, slipper at 4.5mm using Associated pads and spring (lots quieter and more grab), 501x belt 'tensioner', and the aeration shocks. I'm sticking with kit-sized tires, going with some Proline Dirthawgs resulted in a ripped belt (the extra 10mm or so diameter and added grip is too much it seems on the drivetrain when on clean asphalt). I also shimmed the steering where needed (center link), along with some O-rings on the joints to rid the thing of any slop. And to make sure random bumps on the road dont send it on a cartwheeling trajectory, a Futaba G190 gyro takes care of better driving than I am capable of . (it really does work too, the only thing is you need to max out the radio EPA to get full turns while moving)

Now here's the issue...I want it faster! I'm geared at 17/91 for 11:1 ratio, right on Novak's recommendation for this motor. I tried 18/91, went a bit faster it seemed, but also seemed a bit soft as well along with maybe hotter after running it (finger-powered temp guage). Didnt bother testing out 19/91, seemed like 18/91 was already going the wrong way.

I'd go with a 4.5...but the speed calculator I'm using only says about 4 or 5 miles per hour more using Novak's gearing recommendations of 12:1 for that motor, which I'm inclined to follow for the time being.

So that leaves a Velociti 3.5r, a smoking 10500kv motor, the speed calculator says it should be good for around another 10 mph assuming a 13.3 gearing using a 14 tooth gear, and sort of follows the Novak gearing progression.

But Novak doesnt recommend a 3.5r in a 4x4 buggy...why? Is it heat or a lack of torque, or just they are assuming that a real racer might be using it and not some guy that wants to see how fast he can make his car fly? What do you guys think about my 3.5r idea in a Durga? Seen any 3.5's and how did they run? My main goal is something that can be run all the time and capable of ridiculus speeds, not just a gear it up until it blows and thermals all over the place type of machine.

[Spoolio]

Originally Posted by ruf

http://www.tamiyausa.com/product/ite...oduct-id=54079

$80

All of a sudden I like the stock mount a lot more than I did before. $50 max I could stand, $80 is just crazy.

[Spoolio]

The gearing thing on the Durga is always fun .

I ran an LRP Vector 5.5 which they recommend is run at 13:1 on high grip tracks and 14:1 on low grip. According to the helpful oOple gear chart, on a 91/37 spur/dif combination there is no exact match but a 14 or 13 tooth pinion should get the job done. It didn't for me, I ended up with a motor too hot to go near let alone touch. I had started on a 16t originally and worked my way down. To be honest I may have an iffy motor. I've given up with it now and gone to a 12 x 2 brushed motor and I'll see how that works out.

[DCM]

I run a 5.5 on 9.8:1 and that worked fine!

[Hog]

What's the internal ratio for the Durga anyway? Anyone?

[Doomanic]

2.056

[Hog]

Cheers for that.

[SidewaysLS4]

Originally Posted by DCM

I run a 5.5 on 9.8:1 and that worked fine!

Hmm, I guess I could throw in that 19T in there to test it out. Worth 5mph and I think I should be able to see more clearly if there is an issue or not compared to 17T as it is a larger 'step' up in the gearing compared to the 18T I tried.

[dimblum]

Originally Posted by Spoolio

$80

All of a sudden I like the stock mount a lot more than I did before. $50 max I could stand, $80 is just crazy.

Just wait a bit for the part to appear on Ebay or keep an eye on www.stellamodels.net. They have some of the best prices on DB-01 hop-ups I have found. It will likely be half the cost of Tamiya's full retail price.

The other option is the aluminum Motor Mount from 3Racing: http://www.stellamodels.net/catalog/...oducts_id=3309

Not sure how it compares to the Tamiya part, but most people I have talked to said the 3Racing parts are very good quality except for thier DB-01 shock kit. Stick with the Tamiya TRF shock kit if you are going to upgrade the shocks.

[Spoolio]

I think you've come onto the post a bit late dimblum, or perhaps I was a bit non-specific. I've already got a 3Racing mount and true it is very nice, especially for the price I paid from Stella back in January. The "but" is - as I learnt from DCM's post a page back - you can't bolt the Tamiya plate type heatsink to it (when using the carbon chassis). It's only got one hole missing and I suppose if I had the tools to drill and tap it I could but I don't so I can't .

[SidewaysLS4]

Looks like 19T pinion with a Novak 5.5R might actually be good, if the ambient temperature is not too high. I broke down and purchased a half-way decent IR thermometer, threw in the 19T pinion, and did some beating on the car behind work (dusty/clean asphalt). Mostly full throttle and accelleration, max end temp after making a 5000mah lipo go somewhat soft was 175F. Ambient temp of 74F. Still need to check out a couple passes at my top speed testing area to see how much faster it seems and temperatures, but I think it should be ok.

FWIW, those new tires I put on arent so new anymore

[DCM]

glad it worked out there for you fella, gearing wise.... I think the companies are gearing on the side of caution, but with the motor revving it's tits off all the time, it really builds up the heat!

[SidewaysLS4]

Add one more vote for getting CVD's on this car. After the suspension fell apart after some speed tests (a home-made temporary suspension ball failed) it was refreshing seeing the CVD actually attached to the car after it dragged itself back. Sure was nice not going a block away to hunt the dogbone, glad I just got them

[Spoolio]

Eeeeek, run out of Tamiya ball diff grease after building one diff, would it be OK to use normal silicone grease for the other one????

[DCM]

how did you manage that?? I have done about 6 diffs and got plenty left

[Spoolio]

Er, I think I used a bit too much? Not sure how much you are supposed to use, I suppose someone will say you only use a tiny amount huh?

I have scraped a lot of surplus off with my knife but not enough for another diff, so is silicone grease usable?

[ruf]

I guess you could reuse it. You don't want excess lube, it just attracts dirt. I just squeeze a little into the bag holding the diff balls and maybe a light coat on the rings.

[jimmy]

yes, use your other silicone grease. Don't put too much on (!) because it could well fly off and 'infect' your belts with the dreaded slipping disease.