Help me build my car

[Matt111]

Hi I am starting up racing again after many many years and I see a lot has changed
Lipo and brushless being the biggest thing

I am now building a b5m

But I'm not shore what motor/esc or battery capacity I need

Any advise would be appreciated and if you know anyone selling anything please pm me

Thanks

[madmax]

if you havnt raced in a while i would start with a 10.5 t motor, not the fastest but will get you going i would then use a esc what has a boost and or turbo mode so as you get use you can increase your strait line speed
in a 2wd i wouldnt go more than a 7.5t motor what is plenty fast enough

[Ashlandchris]

I agree with above, and in actual fact, unless you have a particularly long straight you may even get away with a higher turn. I use a 13.5t in my yz2 with a speed passion reventon pro esc using boost and it is lovely and smooth in field, but OK on the straight due to boost

[ShaunieT]

Hi Matt

I used a novak 10.5 at club this weekend, i have a spare one of these that you are more than welcome to use if this will help to get you up and running

[danielc3009]

For motor I'd advise against anything faster than a 8.5t in a 2wd but I'd recommend a 10.5t motor to start with as it will be easier to drive. I like hobbywing esc. speed passion Reventon are popular and I've heard good things about sky roc toro esc as well. It's probably a good idea to get a turbo esc if you buy a 10.5t motor. Have a look for a combo motor and esc deal for best value, I know speed passion do them and you get the program box as well.

As for batteries what are you planning to use, saddles or shorties? I use saddles as they have higher capacity, mine are 5800mah and will easily do to races with a 8.5t motor. But shorties are more popular as you have more mounting positions to adjust the car balance but will probably need to be recharged after each race.

[Matt111]

Thanks for the help

I was looking at this
http://www.modelsport.co.uk/speed-pa...roducts/385528

Or maybe go for the 9.5t to get started

With the battery's
Would 4000mah last a race and how high do need the C rating to be?

[danielc3009]

That do fine, that esc got a better spec than mine. 4000mah will easily do a race.

What I understand with the c rating, the higher the rating the quicker the car will accelerate. Someone correct me if I'm wrong.

I wouldn't worry too much about the c rating, most batteries have really high ratings now, about 80-100c. Mine are only 50c.

[simonrhart]

Hi

The battery c rating means the maximum current discharge rate that the battery can handle safely. So a c rating of 100 on a 4000mah battery will give you a max current draw of 400amps. If you look at your speed controller you posted, it draw a max current of 540amps at peak or burst. So in this case a 4000mah battery will not give you the maximum performance fir tbat speed controller that said this depends on bow you drive. Some batteries are now 110c and if I remember correctly 120c.

So to deliver 540amps you would need a 5500mah battery at c rating of 100. In terms of how long the battery would last. Look at the continous amp draw on the speed controller. Its 70amps, this means it will draw 70amps per hour continously. A 4000mah. Attery is only 4amps so if you drove your car at a amp draw of 70amps then your battery would last 3.16 minutes. That said dont worry about this because you will never draw a consistent 70amps.

I run 100c 4amp batteries and get around 10 to 15 mins of runtime.

Hope that helps- typed on phone so pls forgive typos ��
Simon

[Matt111]

thanks for the help

Think I will be doing a lot of overtime to get every thing, it all adds up

On a 2wd buggy what front wheels do you use, I see some are slim?

[danielc3009]

Front tyre choose is down to how much front grip you want and the conditions. From low to high its: ribs, stagger ribs, cut staggers, slim mini spikes and wide mini spikes.

Most people run slim cut staggers and slim mini spikes on the front. You can get the slim cut staggers in high and low profile, for our track high profile would probably be best as they absorb the bumps better. I wouldn't use wide cut staggers as they're for 4wd, but you can use wide mini spikes, which I normally use as my car under steers. You'll need slim wheels or to cut down the rims for the cut staggers. The slim mini spikes can be used on either slim rims or stretched on wide (standard front) rims.

Then there's tyre compounds to choose as well. I've always used yellow compound Schumacher tyres and green blastic tyres for wet conditions, which I think most people do.

For inserts I use Schumacher blues, but make sure you use the correct width, slim inserts for slim tyres etc. If you choose to use low profile tyres you don't need inserts for them.

A good starting point is yellow cut staggers fronts and yellow mini spike rears in the dry and yellow Schumacher mini spike or green blastic spike front and green blastic spike rear in the wet.

You're welcome to borrow my tyres to see what you like rather than buy load of tyres to start with.

Sorry for the long reply but there's lots of choices for tyres

[Matt111]

Thanks for all your help nearly finished building the car hopefully will be at the next meeting
Only the servo to get but I am spent up
What would be the best servo to get for under £30?

[danielc3009]

I'd avoid low profile servos, I had to modify mine to make it fit. Also Try to get a servo with metal gears as the b5m like most buggies doesn't have a servo saver.

I'd say try something like this: http://www.apexmodels.com/gbu0-prods...-SC0253MG.html.