J-PaP

iTrader: (12)

I have tested it a fair few times before. That is simply not the case.

Again I don't know why you are asking about my experience in rc racing. I'm not asking you to post up your experience because it doesn't matter.

I will be dropping the ratio to a 2.25:1 for the blinky car next.

Here is a real life example for you. Have you driven a manual car before?

Put the car in 1st gear and accelerate.
Put the car in 4th gear and accelerate.

The car in 4th gear will not accelerate as fast as in 1st gear. But it will hit a much higher top speed. Try spin the wheels in 1st and try spin the wheels in 4th. It is much harder in 4th gear.

You will find that a cars 1st gear ratio is around 3.1
4th gear ratio is typically close to 1:1

InspGadgt

The more diff balls you can use the more the pressure is spread out among them and the less pressure you will need to use for the same amount of friction...all that makes for a smoother diff. I use the Xenon gears because it lets me use 16 diff balls in the outer diff ball ring.

Kevin CBR

iTrader: (11)

If you are running at TQ in Chino with an F104, get the Kimbrouogh spur gear with the Murff Dog 1/8 ceramic diff balls. Good combo and Sean stocks both. That's what I run in my F104.

Panda

blade072

iTrader: (98)

you cant compare these to a real car........i like your theory though.....
this is how it is...these cars are direct drive.....so the closer you go to 1:1
the faster it will accelerate, thats why you are having wheelspin....

after you try your 2.25:1 , please try 3.0:1 you might be surprised...

InspGadgt

Gear ratio is gear ratio...it doesn't matter if it is direct drive, TC, or even full sized car...the affect is the same because it is simple physics.

If you are noticing a drop off in speed below a numeric 3.0 then that is likely because you have over geared the motor. Different motors have different torque so finding the right gear to maximize both top speed and gear ratio is key to a good setup.

J-PaP

iTrader: (12)

Unfortunately you don't understand. Not really sure how else I can explain it to you. You are incorrect on the matter though.

It doesn't matter that the car is direct drive. It is the same case no matter what the drivetrain.

I have already done what you are saying. I started at 3.2:1 when I first put a 21.5 blinky setup in the car.

sidecarphil1

iTrader: (1)

yes gear ratio is gear ratio , but you cannot compair a fuel motor and electric motors , the toque curve is totally differant

i wis running my F104 at ETS the guys were running around 2.5 , i liked mine at 2.1 the speed was a little better but i lost some corner out pull , this was for me faster

blade072

iTrader: (98)

exactly.....ratio is king.....we have found that 3.0:1 on our track is great.....
i am racing against sakura fgx's...not only am i keeping up with them, but i am actually faster than them down the straight...

the only downside is that if my diff is not exactly set right, they will kill me out of the corners......(dam those gear diffs)

InspGadgt

You are correct in that internal combustion engines and electric motors do have different torque curves...but regardless the effect is the same. A higher numeric gear ratio number yields more acceleration and more torque to the wheels which gives you a higher probability of having wheel spin. If that were not true than the old Aevox powered speed run cars geared at 1:1 would not have needed a push start but they did.

As you said the 2.1 lost some pull...2.1 has more top speed and less acceleration than 2.5 and that is why you lost some pull. Your overall lap time may have been faster at 2.5 but top speed is faster at 2.1.

On your track 3:1 is good...but that may not hold true for all tracks. A 2.5:1 would still yield higher top speeds and less acceleration though if your track was long enough to take advantage of the gearing. 3:1 is still going to have a higher probability of generating wheel spin than 2.5:1 would.

Also you should be faster that the FGX down the straight...you have only 1 gear mesh where the FGX has 3 so you have a lot less drag than they do...Not to mention you should also be significantly lighter than the FGX which will also make you faster down the straight.

blade072

iTrader: (98)

oh i understand, and what was your car like at 3.2:1????
what esc/motor are you using????

fastvee

Hi all, we just had our first ever race in Finland. Sadly only 4 cars and one had to quit after qualifying.

(Formula1 class was a demo class and run in the spare time at the VTR(that is our version of the vta class over the States) and Tamiya Mini summer cup day . classes

But remaining 3 had a race and every1 had a good time, spectators loved it and next race will have more racers.

All 4 cars were tamiya f104 based,X1,PRO,WGP,Mclaren. Diffferent gearing,motors,tires... -and still the racing was tight.

We had 2 (8min) A finals,I won the 2nd final (and the whole GP), first final went to Jonni driving the mclaren (because I swerved his flipped car and hit the track barrier),the onboard footage is from my car(F104X1 Lotus Renault).

I had to ditch the heavy(almost 20 grams, lol)cam from 2nd race, I just had to make sure I will win

both finals here if interested:
http://www.youtube.com/watch?v=KbFpX4YndrM

http://www.youtube.com/watch?v=hEt8mzeV0zM

J-PaP

iTrader: (12)

lrp qc3 and a revtech 21.5

It was exactly as I have said a number of times now. It would accelerate harder (spinning the wheels easier) but have less top speed.

At 2.4 it spins the wheels less and has a higher top speed.

I'm really saying the same thing over and over....

By the way are you thinking of a car being faster with a higher gear ratio because that is what was giving you better lap times around the track?

blade072

iTrader: (98)

you are correct....i should be the one with the wheelspin
and yeah i left it at 3.0:1 because it felt good to drive.....having said that looks like i might be changing my ratio...

I)arkness

iTrader: (7)

it simple, if you want less wheel spin pull the trigger softer

same goes for getting faster times, stop messing with ratios and put the car 1/2 a meter closer to the apex.

blade072

iTrader: (98)

we have a couple of highly modified carbon fibre FGX's
but it makes for some great racing