Setups
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Gearing
Stock gearing for the Mugen Seiki MBX8R, with common pinions and their ratios.
| Pinion | Spur ÷ pinion | FDR |
|---|---|---|
| 12T | 3.83 | 13.42 |
| 13T | 3.54 | 12.38 |
| 14T | 3.29 | 11.50 |
| 15T | 3.07 | 10.73 |
| 16T | 2.88 | 10.06 |
| 17T | 2.71 | 9.47 |
| 18T | 2.56 | 8.94 |
| 19T | 2.42 | 8.47 |
Shaded rows are the pinions most 1/8 4WD buggy setups run on the stock spur.
What pinion should I run?
Tell us your motor and track and get a starting pinion for the Mugen Seiki MBX8R, with the range racers in the class run.
Get a recommendation →Shop pinion gears at AMain →What pinion gear should I use on the Mugen Seiki MBX8R?
It depends on your motor and the track. In the 1/8 4WD buggy class, racers gear by final drive ratio: 1800–2300 kV near 10.06. On the MBX8R's stock 46T spur that is about 16T for 1800–2300 kV. Tight tracks gear down, open tracks gear up. For a starting pinion matched to your motor, use the So Dialed Pinion Recommender with the MBX8R selected.
What is the internal ratio (transmission ratio) of the Mugen Seiki MBX8R?
The MBX8R has an internal ratio of 3.5:1. Final drive ratio = spur ÷ pinion × 3.5. With the stock 46T spur, a 12T pinion gives an FDR of 13.42 and a 19T gives 8.47.
How many teeth is the stock spur gear on the Mugen Seiki MBX8R?
46 teeth. Changing the spur moves every pinion's ratio at once; most racers leave the spur and tune with the pinion.
Kit setup
Kit shock setup. Part numbers link to AMain.
- Front
- 550 cst
- Rear
- 550 cst
- Front
- 5,000 cst
- Center
- 5,000 cst
- Rear
- 2,000 cst
What shock oil does the Mugen Seiki MBX8R come with?
Out of the box the MBX8R runs 550 cst front, 550 cst rear (Mugen Seiki oil), on 8 x 1.3mm (#E2525) front, 8 x 1.3mm (#E2525) rear pistons. That is the kit setup; you will need to adjust it for your track conditions. The RC Setup App can help dial it in.
What springs does the Mugen Seiki MBX8R come with?
The kit springs are 70mm 1.6mm x 9.25T (#E2516) front, 86mm 1.6mm x 10.75T (#E0563) rear. Stiffer springs suit high grip and big jumps; softer springs add grip on slick or bumpy tracks.
What diff fluid does the Mugen Seiki MBX8R come with?
The kit diff fluid is 5,000 cst front, 5,000 cst center, 2,000 cst rear. Thicker front adds steering on power; thicker center sends more drive rearward; thicker rear stabilizes the car under throttle.
Setup Help
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