hblair

Not sure on the ratios. But that's what the tachs are saying and the speed is from gps. I'll check on the ratios tomorrow.

jeff32

my guess is you need around 5000 rpm with 1.5 ratio to run 60 mph with a 21 pitch...

indysupra

iTrader: (3)

Thats what I was thinking.

hblair

Looks like I need to look at the props again. I'm sure they're 21 pitch. I'll report back tomorrow guys lol.

hblair

Here's the prop, 21 pitch..



I saw 60 mph on my friends app on his phone. The likelihood of both tachs being off the same amount I would think would be very low.
Did they make different ratio TRS drives?

Captain YARRR

01scarab29 built twin 383s around 400 hp and is in that MPH range.

hblair

In the 60 or 70 range?

mptrimshop

Just spin your props in, that will get ya close.........

Captain YARRR

I think he's low 70s

737jetmech

iTrader: (1)

My 31 Scarab Viper ran 76 mph with 500 carb engines approx 470 per side .26 labbed b1's for props.