Fastest way to earn Wumpa Coins?
Solution 1:
I found an article on Reddit:
Rewards are determined by the track tier, your finishing position and if it's an online race or not.
This is the basis for both offline/local rewards and online rewards (the only difference is a multiplier for online rewards).
You win the same base rewards in aventure and arcade. The difficulty setting, number of laps or opponents don't matter.
If you're playing in local multiplayer, only the main account running the game on the console gets coins.
Each tier of tracks (there are 4 so far) has a base winning prize: 20, 40, 60 and 80 Wumpa Coins (WC).
Finishing at 1st place gets 100% of the prize, 2nd place: 90%, 3rd place: 85% and 4th-8th place: 75%.
For battles, it's 100% if you win and 75% if you lose.
When playing online, rewards get a x5 bonus multiplier until you earn a daily soft cap, it resets every day.
The soft cap seems to be when you earn roughly ~2500 WC, after that, you earn the standard reward (same as offline).
The counter resets at the same time as the Pit-Stop rotating its content.
The multiplier works for private races too, so if you want to farm coins, you can grind races on Tier 3/4 tracks to maximize gains
Online rewards can be doubled on weekends (x10 multiplier until soft cap then double the base reward).
Track tiers:
Tier 1
Base winning prize: 20 Wumpa Coins
Offline rewards : 20 WC / 18 WC / 17 WC / 15 WC
Online rewards : 100 WC / 90 WC / 85 WC / 75 WC (until soft cap, then same as offline / doubled on weekends)
Crash Cove, Dingo Canyon, Dragon Mines, Roo’s Tubes, Tiger Temple
Tier 2
Base winning prize: 40 Wumpa Coins
Offline rewards : 40 WC / 36 WC / 34 WC / 30 WC
Online rewards : 200 WC / 180 WC / 170 WC / 150 WC (until soft cap, then same as offline / doubled on weekends)
Barin Ruins, Blizzard Bluff, Coco Park, Deep Sea Driving, Hyper Spaceway, Inferno Island, Jungle Boogie, Meteor Gorge, Mystery Cave, N. Gin Labs, Papu’s Pyramid, Retro Stadium, Sewer Speedway, Tiny Temple, Turbo Track
Tier 3
Base winning prize: 60 Wumpa Coins
Offline rewards : 60 WC / 54 WC / 51 WC / 45 WC
Online rewards : 300 WC / 270 WC / 255 WC / 225 WC (until soft cap, then same as offline / doubled on weekends)
Android Alley, Assembly Lane, Clockwork Wumpa, Cortex Castle, Hot Air Skyway, Out of Time, Oxide Station, Polar Pass, Thunder Struck
Tier 4
Base winning prize: 80 Wumpa Coins
Offline rewards : 80 WC / 72 WC / 68 WC / 60 WC
Online rewards : 400 WC / 360 WC / 340 WC / 300 WC (until soft cap, then same as offline / doubled on weekends)
Electron Avenue, Tiny Arena
Arenas
Base winning prize: 20 Wumpa Coins
Online rewards : 100 WC / 75 WC (until soft cap, then same as offline / doubled on weekends)
EDIT:
All tracks give now a different amount of coins, see here.
After the October Grand Prix update, you don't get coins from local battles anymore.