RC10 GTM Buggy (GT tub chassis+trans)

[factory team gair]

Holiday Hangover RC Arenacross race held this past weekend in Moses Lake Washington, was an incredibly well run event that brought out some of the best racers from the region to kick off the 2018 offroad season. After the news of the Cabin Fever race getting cancelled, very special thanks are needed for Justin Wilde, Joe Scales, and a dedicated team of helpers and volunteers for pulling off this awesome event on short notice! The weather turned a little cold in Moses Lake, WA for the week of the Hangover but with the indoor arena, covered popups, and a tarp city with heat it was manageable. Kevin Jelich designed the track complete with hip jumps and jumps in corners that he favors. It was in a nice facility on county fairgrounds, the indoor rodeo arena had bathrooms, power, and a cafe on site. The dirt packed well and held up without much maintenance at all. Weather was 30-40 degrees most of the time. Tekno presence was made here with lots of team representation and the man himself, Ryan Lutz. The new practice format allowed for more wrenching and track time since a driver wasn’t stuck standing in line for 30-45 minutes. All you had to do was make your practice round appointment with the RD desk and pay attention to the order, it was great. I needed all the practice I could get to shake out two unproven cars and to see what I could do after not racing for TWO YEARS!
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RC10 GTM - 2wd Buggy (15 drivers)
The Hangover track was super challenging for 2wd buggies due to the very low traction and large jumps. There was even a consideration by the organizers to have the 2wd classes skip the Tekno hip jump due to the difficulty and possibility of having marshals running up there all the time. In the end everybody ran it just fine. This unique buggy is a RC10 GT tub chassis, transmission, and rear arm mounts with RC10 Team Car suspension, and 3D printed waterfall and battery box I designed. I stayed with front JConcepts Rips all weekend and after experimenting with Holeshots, Blockades, and AKA Impacts, I finally stuck with well worn Proline Bowties. They had tremendous forward bite on the dusty and blown out track, allowing the car to drive really well. The only change I made was for third round, adding 1.25oz under the trans, and 0.5oz in front; I then set the fastest 2wd buggy lap time of the event with a 36.780! That speed did not fully get used, with a few mistakes here and there, but I ended up a close second in the round to Dave Gullickson. In the A1 main I backed it up with 3rd place finish even after getting shuffled to the back in the second lap. A2 was not so good with a popped ball cup (and the millenial marshal who lacked the hand strength to pop it back on) ending my podium chances. I did convince the marshal to put the car down so I could drive it back to me to pop the cup back on, and I finished the main with a few laps just for fun, including a couple of back flips off the Tekno hip jump (easy when the turbo timing kicks in yo).

Hobbywing Xerun 60A
Trackstar 13.5 motor
Gens Ace 4600 shorty
Sanwa MT-S
Futaba S9550 Servo Digital Low-Profile

#rc10
#jqtakeover
#HolidayHangover
#NCT
#Ebuggy
#IvanStewart
http://wilde.liverc.com/results/

[jwscab]

really nice build! I'm building one very shortly.

[Lonestar]

Awesome ! With short arms

Congrats from a fellow frankencar racer !!!

[factory team gair]

This was the surface it was raced on, handled it just fine:

[mikea96]

Very nice build! Do you have any video of it running?

[factory team gair]

Sorry I didn't take any, and I haven't found any yet.

This unique buggy is a RC10 GT tub chassis, transmission, and rear arm mounts with RC10 Team Car suspension, and 3D printed waterfall and battery box I designed. On the standard 3 gear GT trans you get a slipper and large 2.6 diff designed for a nitro truck, which should be able to handle modern 2wd buggy needs. The layshaft is centered 27mm above the chassis, seems pretty low to me. Standard Team Car short arms and hard anodized shocks from 1990-1993 are used, but the arms and knuckles had to be changed out because the original white parts disintegrated due to age. RPM ball cups and Lunsford Ti turnbuckles are needed for racing. I finished off the project by designing and 3d printing the waterfall and battery box, and made sure to use existing chassis holes. A B3 body is used since I intend to switch back and forth between the project car and a standard FT B3. The Ivan "Ironman" Stewart sponsor stickers came from Discount RC Decals, and the stripes are 'carbon fiber' vinyl for cars/bikes.

[jwscab]

Did you have to trim the gearbox at all in the front to get the motor close enough to the spur gear? The way I made my motor mount the motor runs into the one bolt boss and I'll have to run a 93 tooth spur it looks like.

[factory team gair]

I haven't had a problem, I'm running a 13.5 with boost and have been happy with 81 tooth spur and 28-29 pinion. It looks like 26-27 would be as small a pinion I could get with that set up but I have lots of 81-87 spurs from trucks and buggies.

[jwscab]

Huh, that's interesting. Is the motor really close to the chassis?

[factory team gair]

The motor is 16/1000 off the chassis and rubs with flex.

[Mr. ED]

That's a creative approach perfectly executed. Love it

[R16]

I would like to show my appreciation to factory team gair.
He is the person who built this nice RC10gt-e.
https://www.rc10talk.com/viewtopic.php?f=36&t=35552&sid=6b3aeaa76dcdc80b2fe3c58da3f93aa3
I learned a lot from his thread to build my nitro-e conversion buggy. Thank you very much.

to jwscab
Since the final of rc10GT is 2.6 as stated above, you need a roughly 15% bigger pinion to gain the same gear ratio as RC10 (2.25).
I think that 84 spur gear and 27ish pinion can be good start on this conversion (for a modified motor).
I am sure that you can fit 87 spur gear on the GT transmission. For 17.5t brushless motor, it might be challenging.
I don't have any answer yet but I am planning to test it.

[jwscab]

Agreed. I've taken the b4.2 suggested gearing chart and translated the ratios to use a 93 tooth pinion. For a 17.5 unboosted, you need a 39 tooth pinion.

[factory team gair]

Thanks R16!

[factory team gair]

Back when I first built it with a GT rear bulkhead and tower, and was checking the balance: