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Hello everyone, just recently got back into RC and I'm looking to make the old T3 a bit more competitive.

I Purchased a trackstar 7.5 brushless motor and a x-car 120a ESC, and I'm running the kit 87 spur, with pinions from 17 up to 22.
Even with the different gear setups the car doesn't seem to have the short burst punch to clear doubles at the track.

I'm able to keep up with everyone in the corners and straights but rolling doubles / triples is killing my laps... any help would be appreciated.

After a run is your motor hot or you speed control?
What's your timing at
What size batts u using
Have you gone through the truck to make sure nothing is binding
Farmer

Hi,

http://www.oople.com/forums/showthread.php?t=129653

Cheers, Dave.

Are you running it sensored or sensorless? I've got that same ESC on a Trackstar 17.5 in my son's Circuit, and initially I ran it sensorless. It had a delay when you went to full throttle. It would accelerate slowly for 1/2 second or so, then take off after that 1/2 second had passed. I fooled around with all the different firmwares, timing, turbo, etc. Somebody commented that this ESC doesn't handle sensorless well and suggested that I plug in the sensor wire. Sure as can be, that fixed the problem. No more acceleration issues.

This doesn't sound like the same problem that you have, but if for some reason you're not using the sensor cable, try plugging it in to see if it changes the behavior.

Another thing I'd check is how your timing & turbo is set. Some of the firmwares have them set with a delay in the default settings, which may be effecting performance too.

Running turnigy 65c 5k mah batteries, no gear or suspension binding, esc on factory settings, and sensor wire attached.

Reading through the link I suspect it's a calibration or firmware setting or just a bad esc.
It's strange, the truck is a beast on the front straight.. I was going to pick up a second setup for the b2 I'm building maybe I'll swap it and see if the issues still there.

thingsarefun wrote:Running turnigy 65c 5k mah batteries, no gear or suspension binding, esc on factory settings, and sensor wire attached.

Reading through the link I suspect it's a calibration or firmware setting or just a bad esc.
It's strange, the truck is a beast on the front straight.. I was going to pick up a second setup for the b2 I'm building maybe I'll swap it and see if the issues still there.

It could be a lot of things
You could have a setting off in your radio (ex) your expo curve could be off ,throttle delay etc etc
You could also have a loose slipper , tranny could be slipping
There could be many of things ,see if you could borrow someone's motor for a run and see if it acts the same
Where is your timing at
If you read my first post
About motor vs speed control heat
If you come of after a run and your motor is scorching you are over geared if the speed control is scorching your under geared
Farmer

A 7.5T motor seems to me to be a little high (low?) of a motor for a truck. I would think a 10.5-12T would be better. a 7.5 will be really fast, but not have the torque of the higher T number motors. Hence the speed on the straight, but not having the torque to clear the doubles after a corner. A 7.5 is a light buggy motor.