I need help with my VTA car!!! 🤦‍♂️

[waders20]

It's old but an 2019 Xray T4. I'm currently running a 89 spur with a 51 pinion. It's extremely sluggish like I'm not getting full power. In the Bmain I ended up 2nd but was lapped by 1st 2 times. I'm new to onroad this season and want to be more competitive!!!! Any help or insight would be extremely appreciated!!!

 

[Chubaka]

What's your electronics? Chassis pics would help.

 

[waders20]

 

[waders20]

Electronics are hobbywing just stock with the fixed timing vta motor everyone runs with 160tbl protek servo

 

[waders20]

Just an extremely sluggish car. I plan on changing bearings and fresh up fluids but not sure of that's my issue

 

[Chubaka]

@DavidB1126 should know about that esc and timing. I never applied my time to learn it.

Coming from a guy who's not good with electronics, how is the solder joints? Any adapters besides the esc/battery connector? What battery size and chemistry are you running? Do you have a program card for the esc to verify that's not holding power back? Is the spur and pinion too tight?

 

[waders20]

It's my first year with onroad. So I'm a noob on it but want to be competitive like I'm am with 1/8 off road. I know It's a learning thing but I messed with all sorts of gearing with my vta and just can't get any faster. My usgt car I made Tha Amain and ended up 6 out of 16 so not sure what's going on with my vta car.

 

[waders20]

All electronics are good even joints, 5600 may with 200c. It has to be in blinky mode. This is my 2nd year on electric rcs I'm mainly a nitro guy so still learning a bunch. My mesh is great I had guys check it out.

 

[waders20]

Guys have said the T4 is still competitive even with the X4. Just not sure what to do

 

[WickedFog]

Guys have said the T4 is still competitive even with the X4. Just not sure what to do

What is the motor? You're not giving enough info. There are so many things to come into play. I don't know about your Xray's transmission gearing ratio, but on most other RC's, you pinion/spur gear ratio is pretty darned steep, and looks much more like what I would think would be speed run type gearing in most other stuff.

@Littlemotor might be able to help.

But you need to be more specific. Pics of the chassis would help (as Chubaka asked for already with no response). It does us no good to see the body except to say "nice paintjob". That doesn't help you though. So post pics. What turns is the motor you're running. We have no idea what "everyone runs". Is it a 29T? A 13.5T? This makes a huge difference.

 

[Littlemotor]

It’s all math. With no information to speak of, we can’t help.

 

[DavidB1126]

With just the knowledge I know and the info OP gave us. 51T pinion(?) and 89 Spur. Is it possible to gear down on the spur? Or is that 51T pinion a typo and it's actually a 15T pinion?

Most VTA classes are 25.5T motors from my knowledge but might be different to track rules. Those 25.5T motors are Fixed Timing so there is no endbell timing that can be changed. It is also a blinky class, depending on track and race director rules so if it is a blinky class, there is also no electronic timing is you cannot adjust boost and turbo timing.

If your car feels slow, might just be you. Or if you feel slower to the other cars in the grid, take a chance to talk to the local racers to see what they run or what they can help you out with. Or it can also just be your driving or maybe a setting in the radio.

Don't worry I feel the same with 17.5 2wd buggy racing. It's so slow down that straight. But I do keep up with the other racers.

 

[hood52]

Check your bearings, like you suggested. How heavy is your car, what is the minimum weight for your class? If your car is over the minimum weight lighten it up. I would suggest starting with drive line, rotational weight can make a big difference. Have you checked the settings in your esc and radio? Is your throttle rate at 100%? What about your throttle frequency, what do you have that set at?

 

[waders20]

Thank you guys those are many things I will check out! They all are 25.5 motors with fixed timing.

 

[waders20]

 

[RetroThutmose]

Track down the X-ray setup for asphalt or carpet depending on what your surface is and set it up that way. These motors are low on torque but like high rpm. I have a 100 tooth spur and I think it's around 50 on my pinion. Can't see the marking. Mine is slower on the straights than some other cars but faster in the corners. You might try going up a couple teeth on your spur if you can

For asphalt the guys at my track are all running between 1k-2k diff oil

 

[RetroThutmose]

Look up your chassis drive ratio, I know my 2014 is 1.9 and internet says yours is too. But you can measure your final drive ratio. By this simple calculation (spur/pinion)x transmission ratio (1.9)= final drive ratio.

So for me, my spur is 100, pinion we will say 50 since I don't know for sure.

100/50=2

2x1.9 = 3.8

3.8 is my final drive ratio. From some research I did people are aiming for 4.1-5.0 FDR with modern motors. Modern motors make more torque so the gearing is optimized for high speed and efficiency at speed. There are other pinion/spur combinations that can get the same FDR but change the feeling of torque and top speed, but I am not as familiar with how that works.

Higher # FDR = higher top speed, less torque, more efficient at higher speeds.
Lower # FDR = more torque, which can mean better acceleration if you have the grip. But a lower top speed potential.

 

[RetroThutmose]

Quick calculation and your FDR is 3.31, which is low, going to be off pace on the straights

 

[RetroThutmose]

The other thing too is that if everyone is running the same justock 25.5 and you still feel way down on power I'd bet they have a tuned motor that is making peak power within the timing allowed. I have a stock juststock and a tuned justock 13.5 and it is a major difference.

 

[waders20]

Thank you for all the advice. I much appreciate it