corally rdx brushless roll out

[Rick Pfeilstick]

just wondering what rollout to run 13.5 novak system? rdx car and running about 57 mm foam tires.... thanks

[kartermdb]

on a track with about a 120 ft straight and rubber tires we are running a final drive of about 3.8 to 4.0 so be prepared to gear it high

[Rick Pfeilstick]

is that 3.8 to 4.0 inches?

[kartermdb]

no that is actually final drive ratio, we dont calculate rollout on rubber tires because they are all basically the same size. But I believe a rubber tire is 63 mm, so you can calculate from there.

[swopemike]

Med-large 120' asphalt straight, but technical track, we geared around a 4.8 FDR probably because of the tighter sections. That's a 43 pinion and 104 spur on the RDX. We have geared as high as 47 tooth and as low as 42 tooth. That was on 62 to 63mm rubber tires. It would be to 46 to 52 teeth for 57 mm tires. You would go down up to 20% for tight carpet tracks so that gives you a range.

Rollout = 3.14 x diam / FDR = 37.3 mm (4.84 FDR). High end 36.4 to 40.8mm for larger asphalt tracks. Low end ~29mm or so.

[kartermdb]

Thanks, we dont run on much carpet down here, we get to run outside all year round. Hope you get the gearing figured out

[Jereme S]

on carpet with foams i ran 39 and 88 spur with 13.5 worked good on med and large tracks

[f2000racer]

New to brushless and I have a LRP 17.5. What's the gear ratio would one recommend on asphalt with about 100' straights? Or should I just follow the recommended ration from LRP?

Thanks.

[Jeff Brown]

Originally Posted by f2000racer

New to brushless and I have a LRP 17.5. What's the gear ratio would one recommend on asphalt with about 100' straights? Or should I just follow the recommended ration from LRP?

Thanks.

Depends what ESC you are running. If you are running a Sphere TC on profile 8 then I would start around a 4.50 FDR and check temp from there. If you are running at SPX then I would drop to about a 5.3 and start there.

Jeff