Out of box speed for Slash 4x4 (#6808)

[joshua.himes]

I am new to the RC hobby and just purchased a Slash 4x4. I will not be racing but I was interested in the speed I was getting out of the box. I hooked up my old phones GPS program that I use for when I take long bike rides.

My first few runs had the 13/54 gear combination. I was able to hit a top speed of 31.25mph.

I then switched to the 18/54 set up. With this I hit a top speed of 37.75mph. I did notice the motor became much hotter running this gear combination.

With all of this being said I mainly plan to use nimh batteries to run off road and possibly hit some jumps. I would appreciate any tips to improve my off road bashing.

[S.R.C.H]

I would say upgrade to li-po it will be faster and last longer.I used the stock nimh battery and a 2s li-po and have never went back to that battery.And know I have a 3s battery and hardly use the 2s anymore.The 18 tooth pinion gear is for tarmac and speed runs only with the stock system.The 13t is for everything really and if you ever did get a 3s you will probably want to upgrade to a new ESC and motor combo which the castle 2400 would be a good choice.

[robdog]

Off road gear low. Speeds sound correct.


Sent from my iPhone using Tapatalk

[snowslider]

Get LiPo(s). Enough said.

[big_RON]

+1 on any LiPo upgrade.

First off, welcome to the hobby. You've bought the right truck and it will bring you tons of good times.

I was pretty hesitant to invest in LiPo's as well, but quickly noticed it was the definitely the right route to go. I first bought a cheap charger and a 3S 11.1 V 5000 mAh LiPo for like $60 then realized that a 3S was a little much for what I needed and wasn't worth the extra high temps that I was reaching, since then I've bought multiple 2S 7.4V LiPo's and have had a blast. You can pick one up for like $40 and a charger for $40 and it will make a world of difference.

This is also printed in the user manual somewhere but gives you a good idea of how to get the speeds you want. Just be sure to think about using the correct gearing for the right applications.

[joshua.himes]

I made the best choice and am running LiPo now. Here is an update on my speed.

13/54 gear combination with Traxxas 25C 2-Cell 7600mah LiPo. Top speed of 33.37mph
13/54 gear combination with Traxxas 25C 3-Cell 3300mah LiPo. Top speed of 49.48mph

[Hemiram09]

with the 25c-3cell is the run time shorter?

[BrabusBen]

with the 25c-3cell is the run time shorter?

Will definitely be shorter - his mAh is much lower on his 3s - mAh is like the amount of petrol in your tank - the higher it is the more fuel you've got.

Added to that a higher voltage is kinda equivalent to how far you can push the pedal down - ie how fast you can deliver that fuel (that's actually the amps but for this example it helps to think like this)

That's why higher voltage you can go faster (more amps delivered) but the "fuel" lasts less time

This is a very simplified reason but I hope it gets the point across - the mAh is the fuel volume and the volts kinda equate to how fast the fuel can be delivered

In real terms the actual fuel delivery rate depends on how you drive it - if your 2s (7.4V) can do 30mph and lasts say 30mins flat out, your 3s (11.1V) driven flat out (say 45mph) will last around 20mins, but if you drove it at 2/3 throttle (putting about 7.4V across the battery it would last around 30mins but only go at 30ish mph, the same as the 2S assuming the amount of fuel (mAh) was the same in both batts

HTH

[joshua.himes]

I mainly use the 2s because I can run it for about an hour and it does not get the temps to high.

I wanted a small mah volume on the 3s because I just wanted to do some speed runs and didn't plan on running a 3s all day. I get about 15-20 minutes with the 3s I have.

[BrabusBen]

That's not bad at all - nice set up sounds like fun and sensible at the same time ;0)

[Hemiram09]

Will definitely be shorter - his mAh is much lower on his 3s - mAh is like the amount of petrol in your tank - the higher it is the more fuel you've got.

Added to that a higher voltage is kinda equivalent to how far you can push the pedal down - ie how fast you can deliver that fuel (that's actually the amps but for this example it helps to think like this)

That's why higher voltage you can go faster (more amps delivered) but the "fuel" lasts less time

This is a very simplified reason but I hope it gets the point across - the mAh is the fuel volume and the volts kinda equate to how fast the fuel can be delivered

In real terms the actual fuel delivery rate depends on how you drive it - if your 2s (7.4V) can do 30mph and lasts say 30mins flat out, your 3s (11.1V) driven flat out (say 45mph) will last around 20mins, but if you drove it at 2/3 throttle (putting about 7.4V across the battery it would last around 30mins but only go at 30ish mph, the same as the 2S assuming the amount of fuel (mAh) was the same in both batts

HTH

Thanks for the info, I plan on buying the 3s lipo tomorrow and a charger for my son's new Slash Ulitmate, any recommendations on what MAh I should get and what type of charger to purchase. I really don't want to spend a ton since we just purchased the vehicle and the wife is already freaking on how much I spent for the truck.