B4 gearing / racing / general advice

[Redkite]

hello,

Its my first post - I have been a forum lurker for a while !

I have bought a couple of old B4s to try and get back into racing after 20 years absence...

I am using the electrics that came with the buggies- brushed motors and nimh batteries. Can I use LIPO with a brushed speedo / motor - will it make a difference vs nimhs? I am trying to keep costs down at the present... I will upgrade to a brushless system eventually.

Can someone suggest a good ratio - got a whole load of pinions / spur gears to play with !

Also I would love to do some racing however I fear I will be totally rubbish - are many races run stock these days - what would be considered a stock set up now?

thanks all

paul

[Si Coe]

You can use lipos with brushed esc's, and the performance difference over NiMH is incredible. However, lipos need very different care than NiMH's and chief amongst that is they should never be discharged. Virtually all brushless esc's and a few modern brushed ones have a low voltage cutoff that prevents this happening - without it you risk ruining your pack. This is not a major issue when racing as you'll never use a whole pack in a 5 min race, but can be a problem when you practice.
Apart from being a bit quicker, lipos are also cheaper overall. They last longer than NiMH's, and don't mind being used more than once a day. Most racers I know have only 1 or 2 packs tops and simply top them up between heats.

The gearing will depend on the motor and track. Therefore I'd need more information.

There is not much 'stock' racing goes on in buggys anymore. Brushless and Lipo has made full on modified no more expensive than stock. For very little money anyone can have a buggy as fast as they can control, so thats what we all do.

[almunro]

When i used brushed in my B4 with lipos i just bought one of those voltage alarms that plugs into the balance connector of the lipo, and so when it got low it would beep. I mounted it on the battery hold down piece and had it plugged in the whole time i ran the car. They are plenty loud enough for you to hear them from the rostrum.

Something like this Low voltage alarm

Worked a treat and cheap solution.

[Speeed Freak:)]

Originally Posted by Redkite

hello,

Its my first post - I have been a forum lurker for a while !

I have bought a couple of old B4s to try and get back into racing after 20 years absence...

I am using the electrics that came with the buggies- brushed motors and nimh batteries. Can I use LIPO with a brushed speedo / motor - will it make a difference vs nimhs? I am trying to keep costs down at the present... I will upgrade to a brushless system eventually.

Can someone suggest a good ratio - got a whole load of pinions / spur gears to play with !

Also I would love to do some racing however I fear I will be totally rubbish - are many races run stock these days - what would be considered a stock set up now?

thanks all

paul

What's your location? Best bet is to find a local club and go down, there will be plenty of racers willing to help out, racing isant all about speed! Some times the slower cars do better!

[Martijn]

In my local club we still race stock brushed and also brushless.
It's fast enough for our track, I think if we would run mod, they would all spin!

I run a 81spur and 23/24pinion
I'm now testing with a 78spur and 24pinion but the motor gets 70°C
So I'm goning to try a 23t pinion now..