Hemi Predator 212
TAV-2 6" Driven
8T Front Sprocket
54T Rear Sprocket
(6.075 :1 Final Drive Ratio)
13.5" Tires
just under 50mph at 7500 RPM
Black Mamba Jr Cam
gx390 Carb
32 BTDC ignition timing
11:1 CR
7500 RPM all day. No issues revving.
Stock Driven Spring (middle preload hole)
Stock Drive Unit Weights
Blue Drive Unit Garter Springs
Trailsport TS-500 Minibike
165 lb Me
The idea with a CVT is to tune the shift to begin at the RPM where peak HP happens. At least for street or offroad use.
Drag tuning might be different?
Might have issues revving if the engine is has a powerband from 7k to 8k RPM, but the CVT is shifting at 5k and the FINAL DRIVE RATIO does't provide the torque to rev and accelerate.
About 6500 RPM max when I switched the 8T to a 10T sprocket, IIRC. I sold that bike. Maybe it was a unicorn and I should have kept it.
`
BTW: 70:13 with the 7"
and 54:8 with the 6"
are about the same final drive ratio ~ 6 :1.
I expect 7500 RPM is about the limit of a Black Mamba Jr Cam with stock rockers?
TAV-2 6" Driven
8T Front Sprocket
54T Rear Sprocket
(6.075 :1 Final Drive Ratio)
13.5" Tires
just under 50mph at 7500 RPM
Black Mamba Jr Cam
gx390 Carb
32 BTDC ignition timing
11:1 CR
7500 RPM all day. No issues revving.
Stock Driven Spring (middle preload hole)
Stock Drive Unit Weights
Blue Drive Unit Garter Springs
Trailsport TS-500 Minibike
165 lb Me
The idea with a CVT is to tune the shift to begin at the RPM where peak HP happens. At least for street or offroad use.
Drag tuning might be different?
Might have issues revving if the engine is has a powerband from 7k to 8k RPM, but the CVT is shifting at 5k and the FINAL DRIVE RATIO does't provide the torque to rev and accelerate.
About 6500 RPM max when I switched the 8T to a 10T sprocket, IIRC. I sold that bike. Maybe it was a unicorn and I should have kept it.
`
BTW: 70:13 with the 7"
and 54:8 with the 6"
are about the same final drive ratio ~ 6 :1.
I expect 7500 RPM is about the limit of a Black Mamba Jr Cam with stock rockers?
Last edited: