Big Rock Big Rock Track Setup

[Papa_smurf]

Looking for some input on setup/modifications to my big rock to improve performance on a dirt track. The only mods I’ve made so far have been replacing all 4 shocks with Typhon 6S shocks and replaced the servo with an Amazon special 25kg.

I have a mediocre local track that I play on and looking to help out mainly with cornering, reducing spin outs (track is very slick when completely dry) and improving throttle roll-on under acceleration ( so hard to accelerate quick for a jump without losing directional control due to low traction). Of course this comes down to my skill in part.

I realize the BR is not really meant to excel in this application. My next vehicle would likely be a Typhon TLR now that I’ve played enough and know what type of driving I like. In the mean time I’m wondering what else I can do to improve the BR? My current thought is diff oil might be of help to change but I know little about the weights and how it impacts performance. Any ideas are more than welcome. Thanks!

 

[Edough13]

You can try thicker diff oil in the rear to help a little bit with it spinning out. Also changing to tires better suited for the track will help over the stock set.

 

[razorrc]

For sure tires #1, loosen your slipper a little, I suspect those springs are too stiff too.

And the trick to the jumps is to carry momentum up to it so that you don't have to accelerate hard, which as you found out is difficult under low traction conditions.

 

[Yonic]

The first idea i have is to simply convert it to a Typhon 3s, or at least move to a proper tires. the stock BR tires are big and sort of skinny, good for absorbing rough terrain but bad for handling.

 

[Edough13]

The first idea i have is to simply convert it to a Typhon 3s, or at least move to a proper tires. the stock BR tires are big and sort of skinny, good for absorbing rough terrain but bad for handling.

You can convert to a Typhon but won't help with handling unless you change the tires, diff fluids and play with suspension. Also not sure what punch setting your set to as lowering it can help also so you don't get that hard acceleration causing loss of traction.

 

[Papa_smurf]

thanks fir the replies! Lessons learned so far:

New tires, which i guessed would be #1. Thinking the style with a lot of little knobbies are probably best for the slick hard pack with loose top dust (please correct me if im wrong!)

Thicker rear diff oil. 30k? (Zero experience with changing diff oil so this is an experiment for me) No idea if front diff oil change would be beneficial?

Suspension - since i have the typhon 6s shocks/springs ill soften the preload a bunch and see what happens - play with it from there.

As far as punch, i forgot i dropped it one level from default. I definitely need to drop it more and see how it handles. Thanks!

 

[aahwhatever2]

I would also look at getting a better TX and RX. If you can, get one that you can do throttle curves on. You can program a decent TX to help with throttle and steering…even an RX that has a gyro in it would be of great use, unless you are racing, as they might not allow.

 

[Edough13]

thanks fir the replies! Lessons learned so far:

New tires, which i guessed would be #1. Thinking the style with a lot of little knobbies are probably best for the slick hard pack with loose top dust (please correct me if im wrong!)

Thicker rear diff oil. 30k? (Zero experience with changing diff oil so this is an experiment for me) No idea if front diff oil change would be beneficial?

Suspension - since i have the typhon 6s shocks/springs ill soften the preload a bunch and see what happens - play with it from there.

As far as punch, i forgot i dropped it one level from default. I definitely need to drop it more and see how it handles. Thanks!

Sounds like you have a good plan set out and the changes should make a positive difference and give better handling for the track. Keep us updated on the changes made and don't be afraid to ask for help with anything your unsure about

 

[razorrc]

thanks fir the replies! Lessons learned so far:

New tires, which i guessed would be #1. Thinking the style with a lot of little knobbies are probably best for the slick hard pack with loose top dust (please correct me if im wrong!)

Many square small pin tires should work best if it's relatively smooth. Don't use cone-shaped pins.

Thicker rear diff oil. 30k? (Zero experience with changing diff oil so this is an experiment for me) No idea if front diff oil change would be beneficial?

There's no reason to change the diff oil. Leave as is.

Suspension - since i have the typhon 6s shocks/springs ill soften the preload a bunch and see what happens - play with it from there.

Get the arms level.

As far as punch, i forgot i dropped it one level from default. I definitely need to drop it more and see how it handles. Thanks!

You can do that if you have poor throttle control, but it's better to learn how to use the trigger, or even just drop to 2S. Dropping the punch won't let you get the instantaneous response when you need it (such as correcting in the air). Leave at max.

And for some reason you left out one of the most important adjustments, which is to loosen your slipper a little bit.

 

[Papa_smurf]

Many square small pin tires should work best if it's relatively smooth. Don't use cone-shaped pins.



There's no reason to change the diff oil. Leave as is.



Get the arms level.



You can do that if you have poor throttle control, but it's better to learn how to use the trigger, or even just drop to 2S. Dropping the punch won't let you get the instantaneous response when you need it (such as correcting in the air). Leave at max.

And for some reason you left out one of the most important adjustments, which is to loosen your slipper a little bit.

Good call. I missed that. It is already loose compared to what I’ve seen suggested in videos. But loosening it a bit more is worth a try.

 

[419RC]

You also need the biggest WANG on the back for proper downforce. Just kidding but i do love to drive my BRCC on the oval track. It flies around the corner better than my sons 4x4 slash set up for backyard racing.

I think proper tires will help with your cornering, acceleration, and speed for jumps. I would start there and then see what else is needed.

 

[GRC]

Better tires first. If that's still not enough, Thicker diff oil both front and rear will improve excessive slipping. When my tires were extremely worn down and slipping way too much, changing from 10k to 20k both front and rear made a noticeable difference. Since then I got new tires, which of course made a huge difference and I went back to 10k.

 

[razorrc]

You also need the biggest WANG on the back for proper downforce.

I need to make up a sticker for the wing like those old Tamiyas. "The biggest WANG wins!" should work...!

 

[Papa_smurf]

Haven't order tires yet....debating if the Badland MX28's are worth it over the Granite Fortress MTs at over twice the price.

I did adjust my suspension - greatly reduced preload to level the arms and had a run at the track today. Wow what a difference that made! As captain hind sight, seems like there was way too much rebound before. The engineer in me wants compression and rebound adjustments on my shocks now.

p.s. I'm told my wang has proper 'down force'....though its not a one size fits all kind of problem

 

[1.21 Gigawatts]

The engineer in me wants compression and rebound adjustments on my shocks now.

That is what different spring rates and shock oil weights are for.

 

[Papa_smurf]

tell that to a race car mechanic! Haha im guessing spring rates and oil weights are the variables in rc suspension. I wonder, are high end rc dampeners using adjustable orifices?

 

[razorrc]

RC race cars have a selection of pistons with different holes and number choices to adjust high-speed vs. low-speed damping characteristics, some aftermarket companies sell pistons with different compression and rebound tunes:

Example:
https://visionracingproducts.com/Associated_c76.htm

 

[Papa_smurf]

So it is done. Being new to this hobby i continue to be amazed at how advanced these little things can’t be.

 

[GRC]

Haven't order tires yet....debating if the Badland MX28's are worth it over the Granite Fortress MTs at over twice the price.

On dirt the MX28's provide noticeably better traction.