B4 Gearing Help (Mamba Max Pro - 7700kv)

[andylinney]

I recently transplanted a Mamba Max Pro with a 7700kv motor into my B4 and whilst it's ridiculously fast it's getting seriously hot.

I wondered what a good place was to start with the gearing?

Not sure of the spur size but there's a 19t pinion on there just now. It's going to be used for back garden driving and occasional indoor meetings on polished floor / carpet with about 20 metres worth of straight so acceleration is more important than all out top-end.

[BeachBuggyPhil]

You'll need to go down a little in pinion I'd guess going by this.
http://www.iowarctracks.com/viewtopic.php?f=74&t=6732&sid=a0495040d94557ac8f18afc929bcaa53

[oddski77]

You'll need to go a little in pinion I'd guess going by this.
http://www.iowarctracks.com/viewtopic.php?f=74&t=6732&sid=a0495040d94557ac8f18afc929bcaa53

I think you should also go down to maybe 5000kv... A 7700 is overkill for 2wd. If you need top end, add some timing e.g over 19000 rpm if you are able to do that.

[Lee1972]

I recently transplanted a Mamba Max Pro with a 7700kv motor into my B4 and whilst it's ridiculously fast it's getting seriously hot.

I wondered what a good place was to start with the gearing?

Not sure of the spur size but there's a 19t pinion on there just now. It's going to be used for back garden driving and occasional indoor meetings on polished floor / carpet with about 20 metres worth of straight so acceleration is more important than all out top-end.

My son runs one of these Mamba Max Missiles in his B4 he runs the 6900kv with an 81t spur and an 18t pinion but we run on a track with an approximate 28 metre straight and it's bonkers fast and he tells me it never maxi's out. I'm trying to persuade him to drop to an 8.5 or 7.5 turn motor but my pleas are currently falling on deaf ears :thumbdown: