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Stock gearing for the Mugen Seiki MBX8T, with common pinions and their ratios.
| Pinion | Spur ÷ pinion | FDR |
|---|---|---|
| 12T | 3.92 | 18.02 |
| 13T | 3.62 | 16.63 |
| 14T | 3.36 | 15.44 |
| 15T | 3.13 | 14.41 |
| 16T | 2.94 | 13.51 |
| 17T | 2.76 | 12.72 |
| 18T | 2.61 | 12.01 |
Shaded rows are the pinions most 1/8 4WD truck 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 MBX8T, with the range racers in the class run.
Get a recommendation →Shop pinion gears at AMain →It depends on your motor and the track. In the 1/8 4WD truck class, racers gear by final drive ratio: 1800–2300 kV near 13.97. On the MBX8T's stock 47T spur that is about 15T 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 MBX8T selected.
The MBX8T has an internal ratio of 4.6:1. Final drive ratio = spur ÷ pinion × 4.6. With the stock 47T spur, a 12T pinion gives an FDR of 18.02 and a 18T gives 12.01.
47 teeth. Changing the spur moves every pinion's ratio at once; most racers leave the spur and tune with the pinion.
Kit shock setup. Part numbers link to AMain.
Out of the box the MBX8T runs 600 cst front, 600 cst rear (Mugen Seiki oil), on 6 x 1.3mm (#E2569) front, 6 x 1.3mm (#E2569) 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.
The kit springs are 75mm 1.5mm x 7.5T (#E0574) front, 86mm 1.5mm x 7.75T (#E0578) rear. Stiffer springs suit high grip and big jumps; softer springs add grip on slick or bumpy tracks.
The kit diff fluid is 10,000 cst front, 10,000 cst center, 7,000 cst rear. Thicker front adds steering on power; thicker center sends more drive rearward; thicker rear stabilizes the car under throttle.
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Your Mugen Seiki MBX8T is in the RC Setup App
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