Italian racer

iTrader: (20)

Hi Charlie,

What is the best gear ratio to run with the 13.5? This was without the Sintered arm also. Would that change the recommended final drive?

Just ran it at a 4.8 final and it shut down on me after 4 mins. Any suggestions?

Thanks
Nick

Marcos.J

iTrader: (239)

i would start 1 or 2 more teeth on the pinion over what you would normally would gear a normal stock motor and start from there

Jochim_18

iTrader: (10)

5.5 - 5.7 FDR is a good starting point lower than that and will thermal. But it also depends on the track.

andrewdoherty

iTrader: (49)

I ran my 13.5 in our rubber tire carpet class with a 5.2-5.6 fdr tonight with two fans mounted on a team tamale fan mount and the motor ran wonderfully. We shoot for lap times around 14-15 seconds. I never got a temp reading above 110*. I am running the sintered rotor using an Orion 4800 Li Po in an RDX. I estimate the ambient temp at our track tonight was somewhere around 70*

STEALTH

iTrader: (21)

Interesting Questions... I hope BOB can answer them for all of us INFERNO.

nexxus

iTrader: (315)

Started out with the 26/86 ratio today, that's way too hot, motor got to 175 degrees after 2-3 minutes, lots of trial and error, settled on a 19/86 ratio which is one tooth above what guys were gearing their Brushed Stockers at, motor peaked around 145 during a race, clip on heatsink only, no fan, track temp 125 degrees. (Yes it was a warm day, around 90-95)

Italian racer

iTrader: (20)

Much appreciated guys!!

I will try running it alittle hight then the 4.8 range and see what happens.

Thanks
Nick

Italian racer

iTrader: (20)

Much appreciated guys!!

I will try running it alittle hight then the 4.8 range and see what happens.

Thanks,
Nick

syndr0me

iTrader: (32)

Any idea what's going on with this GTB? Is it just a giant purple fan on a regular GTB? It came from this video, about 10 minutes in.

Jochim_18

iTrader: (10)

Only thing I can think of is for cooling.... That is greg drescher associated prototype car (TC5).... If you guys watch the video he still thermal eventhough his using that huge fan.

syndr0me

iTrader: (32)

I imagine it was shutting down because of the motor, not the ESC. I doubt they could use sintered rotors in that race, which surely would have helped a great deal.

Jochim_18

iTrader: (10)

I bet he used a sintered rotor since 3.5r comes stock with a sintered rotor. GTB ESC when it reaches over 170 deg F It will thermal thats why you gear your car base on the temp of the ESC and not the motor.

Charlie

If that is footage from the worlds. Sintered was Not Legal.

The big fan was an effort to increase airflow inside the car. Cool the ESC more as the track was very large and used quite a bit of braking. Personally I don't think the large purple fan is any better then the small ones, but it was the "worlds" and it was very hot.

From our notes, it seems they missed out on some testing due to the rain, so we never were able to nail down the gearing. We figured craigs car was maybe a tooth overgeared when he shut down during the 2nd main.

We geared down for the 3rd, but contact broke the car. For the short time he was on the track power was not "undergeared". So it's likely we could have geared down further.

Thanks Guys,
Don't forget you can always email us directly if you want answers "strait" from the horse's mouth.....

Charlie

Also, We gear based on the temp of the motor. We try for around 160-175F at the end of 5 minutes.

Jochim_18

iTrader: (10)

Thanks for the info and clarifying that charlie.