How much extra speed will a 3s lipo add?

[gtione]

So I took my newly build JK Rubicon out for its first decent run today and it performed well.

I chose initially to go for a 2S lipo set up as I have not been convinced if it would add value to the kind of use I would need.

On a 2S set up I am quite pleased really but wouldn't mind a bit more top end speed. So my question is if I moved to 3s with all of its associated costs how much extra top end would I achieve with the stock gearing?

I am running a Team Tekin fx-R esc with a 35t brushed motor as well.

I have added a pic of the start and end of today's run. Did it both down and back up again.





Thanks in advance.

[sixtyspokes]

Wow no official numbers but my guess is (2s) brisk walk to (3s) light jogging??? However, I geared down once I switched over to 3s. My recommendation, go 3s. It's really not that expensive once you have the right battery charger.

[gtione]

Originally Posted by sixtyspokes

Wow no official numbers but my guess is (2s) brisk walk to (3s) light jogging??? However, I geared down once I switched over to 3s. My recommendation, go 3s. It's really not that expensive once you have the right battery charger.

Yes a brisk walk is about it on 2s. With the 3s I have to consider a BEC and programmer as well as new batteries. I have a suitable charger so at least that cost is void.

[cox308]

Theoretically you'd be going 1/3 faster. In reality you'd probably have to gear down or risk over heating. Even after gearing down a little you'll still be going noticeably faster and you'll have loads more torque and a good bit more low end control.

I'd recommend going 3S and don't look back.

[sixtyspokes]

I totally missed the obvious... what a nice oceanfront! Is this England? I'd be itching to kayak and explore that calm water! You must have had a great day! Really jealous!

[gtione]

Yes this is England on a nice spring day. The area is Dorset on the south coast at a place called Durdle Door. Very pretty indeed.

It is a massive decent from the parking area to the beach, just short of 800ft. The initial decent is full of paths and then the final bit is stairs with paths either side. So it was great got the full run all the way down.

The beach was all shingle (stones) which provided a great play area in between the beach goers. Also managed to keep a few small dogs entertained.

The trip back was even better as it made me think a lot more that on the way down but I got there. What I was really surprised about was how little battery power I used. I still had 61% left from a 2S 4000 mah lipo. Amazing considering the elevation and about two miles of driving.

Get this on the way back my wife who always goes on " I don't see the point of this thing" " oh this is so embarrassing being public with this little car", asks me if she could have a go! Think I have won her over now.

There where lots of people out on various boat types and yes the water was dead still. The water was one inch cold if you get my meaning but that did not seem to put people off.

It was a two hour drive from London for me but well worth it and would defo go back to explore the coastline again.

[tnspark82]

I have a friend that lives close to there!!!! We are supposed to visit them next summer and I am very excited. I wonder if they would let rc cars on a airplane???

[gtione]

Originally Posted by tnspark82

I have a friend that lives close to there!!!! We are supposed to visit them next summer and I am very excited. I wonder if they would let rc cars on a airplane???

Of course they will just check on the lipo batteries though, some carriers don't allow them at all. Otherwise just by some online here and have them shipped to your mates address.

That part of the country is awesome and even further down into Cornwall as well.

You could always buy your car a seat of its own just to be sure!

[gtione]

Originally Posted by cox308

Theoretically you'd be going 1/3 faster. In reality you'd probably have to gear down or risk over heating. Even after gearing down a little you'll still be going noticeably faster and you'll have loads more torque and a good bit more low end control.

I'd recommend going 3S and don't look back.

Thank you that is great advice and makes perfect sense.

[Jus]

No matter what gearing you have or what motor you run, 2s is boooooring and 3s is fun as hell. That's been my experience.

I rarely use any more than 1/2 throttle but when I need the power it's there. So there really is no downside.

[Calderwood]

I can't imagine using 2s for anything besides indoor foamies or for racing classes that require it.

[Collective itch]

Definitely go 3s. Much more wheel speed which comes in handy. I'm Dorset to, I was down at high cliff in Christchurch today. When you next planning a run at durdle?

[gtione]

Originally Posted by Collective itch

Definitely go 3s. Much more wheel speed which comes in handy. I'm Dorset to, I was down at high cliff in Christchurch today. When you next planning a run at durdle?

Was my first time to Durdle yesterday to be honest. Lovely place and great terrain for trailing/crawling. If there is more of that that you can recommend while I leave the family at a local beach etc then defo keen to hook up. Thx.

[nersik]

Theoretically you'd be going 1/3 faster.

Where did you get that??

Theoretically you have 35t = 1565 rpm/V.
2s voltage is 7.4 V => 11580 rpm
Switching to 3s will give you 11.1 V => 17370 rpm or + 1/2 (50%).

Your rig will be 1.5x faster on 3s vs 2s on same gears.

[Duxx]

All theories aside, technically 3s is 1s faster than 2s.

Scale beer cans, now that's the schlitz!

[TheAxialNut]

Change back to the 27 Turn and add the 3s to your FX-r, i guarantee you will be happy, just use the stock ratio, cannot run the whole pack full out (full throttle), but when you need the wheel speed to get up and GO!

IMHO.....

[05Fronty4x]

I normally run 3s, but tried a 2s pack just because. The main difference I noticed is that it took less effort to navigate obstacles smoothly because it's less jumpy if you give it a little too much throttle. If you are going to be running trails or playing around in good sized areas then I think a switch to 3s is a good idea. Just be sure to monitor your motor temps when your trigger finger gets heavy because stock gearing is relatively high. Re-gear if necessary.

[nersik]

All theories aside, technically 3s is 1s faster than 2s.

What?
3s means 3 x 3.7V cell elements in series. Nothing to do with speed.
Motors rpm is ~linear to voltage.

Did someone actually measure speed on 2s and 3s?

[cox308]

Originally Posted by nersik

Where did you get that??

Theoretically you have 35t = 1565 rpm/V.
2s voltage is 7.4 V => 11580 rpm
Switching to 3s will give you 11.1 V => 17370 rpm or + 1/2 (50%).

Your rig will be 1.5x faster on 3s vs 2s on same gears.

This is exactly what I meant. It was all clear in my head it just kind of came out wrong

The logic I was using is that the 2s is 1/3 slower that 3s but you are right. 50% faster and 33% slower.

Are we confusing the shit out if everybody now??

[gtione]

Originally Posted by cox308

This is exactly what I meant. It was all clear in my head it just kind of came out wrong

The logic I was using is that the 2s is 1/3 slower that 3s but you are right. 50% faster and 33% slower.

Are we confusing the shit out if everybody now??

A while ago actually.