Gearing?

[sime46]

Just wondering what the experianced guys may suggest for my LRP s8bxe team car? Its on an lrp 2800kv motor running 4s. Its as box I think, but thats not always the right way I'm finding. Thanks chaps. Also, could anyone point me in the right direction for connectors for my battery/speedo please? The battery has the big red one peice plug with what appears to be a male and female inside. Where can I purchase some more to get this show on the road/track, prefferably uk if poss. Thanks again.

[BRS]

EC5 connectors seem to be one of the best http://cgi.ebay.co.uk/EC5-battery-CO...item518fe71d9a

Got some from this person on ebay all good other day.

Looks to me like you have too high KV motor there for 4S? I read around 30,000rpm is the sweet spot 41,440rpm seems alot, 2000kv for 4S by my reckoning?

[Marvin]

I would put 2800KV on 4S as a little high as well, but the LRP motors are a little underpowered in comparison with the Castle, Neu motors that we have based that hypothesis on, so maybe the LRPs like to run a little higher RPM.

According to the manual, for 2800KV on 4S, you want to run 11/44 gearing on an S8BXe (11T pinion, 44T spur). By my rather rapid (and probably wrong) calculations, the differentials in the S8BXe are at 14/49.

According to my calculations, that comes out at about 48 mph including tyre ballooning (using the same methods and constants as I always do when calculating gearing), which is a touch high. I'd suggest bringing the pinion down to a 10T for 44 mph, or a 48T spur with the 11T pinion (preferred, as the teeth won't wear as quickly).

[Marvin]

Oh yes, and I'd also go with EC5s, like BRS suggested - I've been using them a long time now.

The trouble with the 'red plugs' you speak of is that there are so many slightly different types, whilst an EC5 (even a copy EC5) is still an EC5 - in the same way as all Deans work together technically.

[sime46]

Mint. Cheers fellas. I appreciate the info. I'll get the parts ordered tomorrow.

[sime46]

Just looked at the car and its actually on a 13t pinion with a 44t spur! Crikey. Overgeared???

[DaveG28]

Sounds it from the other posts, but may be worth checking the rctech threads for more people who run those electrics from Lrp, as Marvin said from what I've heard the motors are much different power wise than other motors and probably need different gearing?

[Marvin]

Originally Posted by sime46

Just looked at the car and its actually on a 13t pinion with a 44t spur! Crikey. Overgeared???

Yeah, I got my figures directly from the SPX8 manual - and that's what LRP recommend for the S8BX with the 2800 on 4S.

I think a 10T would be better, but that's not a good size to run.

[sime46]

I'll get that swapped out asap. can they(pinions) be bought over here guys? Where can you reccomend?

[Marvin]

The HPI/Hot Bodies pinions have always been good, and are available in a wide variety of sizes. I think Wheelspin Models keep them in stock. Failing that, Novak pinions, or Losi pinions. With the Novaks, make sure they are Mod 1 (they do two different ranges, that are easy to confuse).