What runtimes are you all getting then...?

[DaveG28]

Just wondered what runtimes everyone is getting, if anyone could let me know, along with what motor/cells your using?

[electric]

about 20minutes on some ftx 5000mah 7.4V 20C packs in a Losi 8B with mamba monster esc, medusa motor and rc monster motor mount.

i have some zippy-R 14.8v 4500mah 21/35C's on the way and would imagine they would give a similar run time...

[Marvin]

I'm getting about 12 minutes driving hard. This is with Flightpower 4S 4350mAh Lipos in a Hyper 9E. Motor: Medusa Research 2000kV motor with a Castle Creations Monster Mamba.

Soon I'm looking at getting some 5S ~4500mAh Lipos to get that run time to about 15 - 16 minutes.

[Doomanic]

Managed a 15 minute nitro final using a FlightPower 4S 4500mAh 30C and a Neu 1512 2600kV motor.

[Doomanic]

i have some zippy-R 14.8v 4500mah 21/35C's on the way

Where from?

[electric]

Where from?
hi, i got them off the french ebay site. they are a bit long for my battery trays (about 3cm too long) so i may sell them as i have to strap them to the top which is neither safe or good for low COG.
if you are interested PM me an offer (i have 2 4s packs)

EDIT: i forgot to say these zippy-r lipos are far better than the other zippy lipos and are reported to be made of enerland cells in korea...

[niggs98]

they are a bit long for my battery trays ...

i had a simlar prob with the 14 volt trackpower lipos at neo but found that i could turn the cels on there side and run them diagonal across the tray. this ment they still ran on the chassis line although i did have to cable tie them in lol. now got to try and find some 10k mha lipos so i can do a 30 min final :P as want to kick some nitro ass :thumbsup::woot:

[HarlowS]

I did a 15 min final at a border counties league last week and pulled in for a lipo change at 10 mins just in case (was grass track so didnt want to risk it). Pit team did a great job of swapping it in 23 seconds lol !!! and still managed to win by a lap :p

[Doomanic]

hi, i got them off the french ebay site. they are a bit long for my battery trays (about 3cm too long) so i may sell them as i have to strap them to the top which is neither safe or good for low COG.
if you are interested PM me an offer (i have 2 4s packs)

EDIT: i forgot to say these zippy-r lipos are far better than the other zippy lipos and are reported to be made of enerland cells in korea...

What are the exact dimensions?

[DaveG28]

I did a 15 min final at a border counties league last week and pulled in for a lipo change at 10 mins just in case (was grass track so didnt want to risk it). Pit team did a great job of swapping it in 23 seconds lol !!! and still managed to win by a lap :p

Haha yeah that pitstop rocked!!

what mah and kv were you running by the way? Had chance to see what was left in that first lipo by the way?

[HarlowS]

I was running a Tekin 2650kv motor and they were 3700mah packs in the final. havent discharged them yet so not sure. If i was more prepared i would of ran the 5000's ;) But hey ho :)

[DaveG28]

Any tips on where to get batteries? Hoping to race in may but only have one pack!

[HarlowS]

Not really, i picked up a couple of 3700's from the airplane section on ebay, apart from that there are some good value packs from hong kong at about £40, they may be only 20C rated but the 3700's that i run are 20/22C and the car wasnt slow :)

[Marvin]

I would look at Flightpower packs (either eBay or almost all model shops that sell Heli's/Planes) as they are fantastic quality and you can get them in practically any Voltage, Capacity or Size. Otherwise 2 Trakpowers in series or any of the car race packs really (Orion, LRP/Nosram, Core RC etc).

The Overlander Tornado packs are also worth a look; good quality cells, reliably rated and in various sizes. They tend to be slightly cheaper than Flightpowers though, but are still very popular in Helis, so many places sell these too.

[DaveG28]

I was running a Tekin 2650kv motor and they were 3700mah packs in the final. havent discharged them yet so not sure. If i was more prepared i would of ran the 5000's ;) But hey ho :)

Were you running 4S 3700 ?

[DaveG28]

I would look at Flightpower packs (either eBay or almost all model shops that sell Heli's/Planes) as they are fantastic quality and you can get them in practically any Voltage, Capacity or Size. Otherwise 2 Trakpowers in series or any of the car race packs really (Orion, LRP/Nosram, Core RC etc).

The Overlander Tornado packs are also worth a look; good quality cells, reliably rated and in various sizes. They tend to be slightly cheaper than Flightpowers though, but are still very popular in Helis, so many places sell these too.


Are thunderpower any good?

[Marvin]

Yes, Thunderpower are also good. They are made from very similar cells (from the same manufacturer) as the Flightpowers. PolyQuests are also worth a look.

[HarlowS]

Yes were all 4s packs, Maxamps, thunderpower and flightpower


Were you running 4S 3700 ?

[electric]

What are the exact dimensions?
20.6cm long, 4.7cm wide, 2.8cm tall

[Doomanic]

20.6cm long, 4.7cm wide, 2.8cm tall

Arse. It won't fit in my car either.:(

[DaveG28]

Yes were all 4s packs, Maxamps, thunderpower and flightpower

So, I'm not sure how comparable different makes are, but running losi electrics with the 2100kv motor, if I go for 4200 4S cells they should definitely go for longer than 10 minutes yeah?

I'm hopoing to enter a few meetings where finals are 22 mins, I have one 5000mah 4s pack (the losi one which by all accounts is a bit s**t), would that and a 4200 4s see me through 22 mins easily enough?

[electric]

So, I'm not sure how comparable different makes are, but running losi electrics with the 2100kv motor, if I go for 4200 4S cells they should definitely go for longer than 10 minutes yeah?

I'm hopoing to enter a few meetings where finals are 22 mins, I have one 5000mah 4s pack (the losi one which by all accounts is a bit s**t), would that and a 4200 4s see me through 22 mins easily enough?
what is the C rating of the 4200?
my 5000's that have about 4550 left in them can easily do 15 minutes flat out but it depends on gearing e.t.c

[Marvin]

As electric says, it depends on the gearing and stuff, but, geared to the same speed as the nitros I get about 12 minutes with 4350mAh 4S so 10 minutes with 4200 should be easily acheivable. Also, as you are already an electric driver, you should be a bit smoother anyway, so you should be able to get more run time than me
(faithful nitro driver originally; throttle on "waaah - waaah - waaah" through the corners:lol: - not good for battery life)

[DaveG28]

what is the C rating of the 4200?
my 5000's that have about 4550 left in them can easily do 15 minutes flat out but it depends on gearing e.t.c

It'd be 40C, the 5000 is 15c I think. Not an ideal balance having 2 such different cells, but on a 2100kv geared sensibly (to nitro pace) should they do 22 mins between them? And should the 4200mah ones manage a 10 min heat?

[Marvin]

The capacities should both easily make 10 minutes each (probably about 11-12 minutes).
15C is unlikely to be powerful enough. (5*15 = 75A). Most people reckon that you need about 100A continuous. Also it does depend on the Burst current available. With my Flightpowers I have 50C burst (4.35*50 = 217.5A)

[electric]

you will probably be better off running 20C's.
burst is only for a few seconds though and for most of the run you won't use very many amps at all. take a 5000mah pack for example if you get 10 minutes runtime out of it (quite short i know but if you really are tearing it around a track possible) you are only using 30A average over the run ;)

[Marvin]

However, it's the bursts that kill the lower C packs off. My set-up has bursts of about 150A, which a 15C pack (which is probably only capable of 25-30C burst), even of high capacity, is unlikely to be able to provide, and so will probably puff.

[DaveG28]

It's ok, I put the wrong figure, it's 25c in reality!

Think for my first meeting I'll just not run the final, tbh I want to be able to make 25 mins on 2 packs of 4s, one of which is 5000mah, and not sure 4200mah in the other pack will give me enough will it? May need to get another 5000, will that give it enough?

[Marvin]

I say give the final a shot, you don't know what sort of run time you are going to get until you've tried.

I would have thought that you could get 25 minutes between the two packs, I use 4S 4350 and get 11-12 minutes on a rough track, so probably more like 13-14 on a smooth one. 5000 is 115% of 4350, so you should (hopefully) expect 115% of the run time (12 * 1.15 = 13 minutes 48 seconds - perhaps a bit exact...) but 12 + 13 and a half is 25.5 so should be enough. Just don't do the warm up bit at the start, turn the car on and stick it on the line with 15 seconds to go.

[DaveG28]

Yeah actually from that they should last (especially considering time lost in pitstop too), what I mean't was I haven't actually bought the 4200 yet! I'm only planning one meeting before mid July, so might just do the first (in May) with just the one 5000 battery then not finish the final, and wait to see what comes available over the next mth or so battery wise, rather than getting a second one right now! Might leave me better set for the meetings I'm doing later in the summer!

Dave

[Marvin]

Oh, I see. That's a pretty good idea to be honest. As for the 2nd battery, I would still go with non-hardcased 14.8V as the quality of the packs are generally better than the hardcased 4S packs.

[ojoloco]

I can get around 30 minutes or more from an 8000mah 3S battery, running a MMM 2200Kv combo on my Xray 808.

[Ben Turner]

Iv got a Castle MMM/2650kv set up, and iv ordered some 22c 5000mah packs, but i really want to try it out! Iv got some newish trakpower 20c 3200mah packs from my b4. I know the C rating is a bit low but do u guys think they will be ok for a few short runs? Anyone had any experience of running them in 1/8th? Im dying to drive it but not at the expensive of puffing lipos :(

cheers,
Ben

[HarlowS]

I have 25C flight power cells and Max amps cells, 22C Tornado packs and a Flightpower 20C, and to be honest i cant notice the difference so i think you will be fine, especially over short runs, i managed to get 21 mins out of the Flightpower 5000mah on a loose dirt track, obviously if you are on something like grass or astro where you have the grip your run time will reduce a bit.

[AmiSMB]

Iv got a Castle MMM/2650kv set up, and iv ordered some 22c 5000mah packs, but i really want to try it out! Iv got some newish trakpower 20c 3200mah packs from my b4. I know the C rating is a bit low but do u guys think they will be ok for a few short runs? Anyone had any experience of running them in 1/8th? Im dying to drive it but not at the expensive of puffing lipos :(

cheers,
Ben

The Castle Creations Monster Mamba Max states in the instruction manual not to use anything less than 5000mah for a reason! I would not try it with your 3200mah packs as they will have too much current drained from them and are likely to puff up and become useless.

[Marvin]

I've got to agreewith AmiSMB with this, 3.2A * 20C is only 64A continuous, which is not going to be enough. Running packs under 5000mAh is fine, but the C rating must make up for it, so you would need 30C packs at least for 3200mAh to be fine. Even then they will be quite pushed 3.2 * 30 = 96A which is about right but they will get quite warm and won't last as long (i.e. as many cycles) as a larger capacity pack that isn't as stretched.

[DaveG28]

Guys, if running 2x2s will 4mm connectors handle the load ok?

[electric]

Guys, if running 2x2s will 4mm connectors handle the load ok?
yea that should be fine :thumbsup:

[electric]

Iv got a Castle MMM/2650kv set up, and iv ordered some 22c 5000mah packs, but i really want to try it out! Iv got some newish trakpower 20c 3200mah packs from my b4. I know the C rating is a bit low but do u guys think they will be ok for a few short runs? Anyone had any experience of running them in 1/8th? Im dying to drive it but not at the expensive of puffing lipos :(

cheers,
Ben
also you should only use a pair of lipos if they have the same amount of use otheriwse you will puff one as i found out the hard way with some 2s lipos :thumbdown:

[DaveG28]

also you should only use a pair of lipos if they have the same amount of use otheriwse you will puff one as i found out the hard way with some 2s lipos :thumbdown:

I've been trtng to ask about this in another thread, is it safe to charge the 2 batteries separately or do you need to try and do them as one?

[Marvin]

No, you can charge them separately, but most prefer to charge them 'as one battery' in series (so it becomes a 4 cell). A custom balance lead would need to be made, but it's not that difficult. The only reason that people like to charge two at once is that two are required for the car at once. The charger cuts the Lipo charge off when the cells reach capacity, so it doesn't matter if you charge them separately. Even if they are both connected, the charging stops when one cell reaches full voltage, and the charger enters balance mode to bring the other cells up to the peak voltage. Therefore it is irrelevant whether you charge them at the same time or separately.

I can't see why using two Lipos of different ages is a problem, so long as they are the same cells (so have the same capacity and discharge rating (C)) there shouldn't be a problem. Unless one is completely knackered of course and the other is brand new or something. A couple of cycles different won't be a problem though.

4mm connectors are enough to run 1/8 Brushless. It's only when people run them in really high power applications that they start to really heat up and efficiency is lost.

[DaveG28]

Guys, as an update, ran my first meeting at the weekend, with the losi buggy and electrics, 2100kv motor, losi 4s 5000mah battery. It was at Sutton, a grass/dirt track which had what I'd guess is a long straight on it.

In 5 min heats was using 1800-1900mah. Pulled the car off 11mins into the final and can't be sure yet but as an educated guess had used around 3600mah, which I guess makes sense as you still only do one set of warm up laps etc. Depending on final drop off on the cells would guess maybe around 13mins is do-able. I was driving flat out at all times and made no effort to make the battery last. I didn't have a temp guage so not really sure how hot it was running, no thermalling though so presumably can't have done any overheating damage?

Speed wise the top nitro's had more top end (roughly the difference between using a 5.5 and a 6.5 in 10th) but nothing could touch the losi on bottom end or mid range grunt, it was awesome! I can't think of any tracks I've seen where more top end was necessary. Certainly was fine for Sutton, qualified 2nd and led from the start of the final till I pulled off! I think the electric has quite an advantage over the nitro's!!

[Marvin]

I think you should maybe gear up very slightly. What pinion/spur are you using at the moment?

The electric should be able to have the same if not higher top speed, yet still be soooooooooooooooooo much faster out of corners.

Glad you liked it though :thumbsup:

[DaveG28]

I think you should maybe gear up very slightly. What pinion/spur are you using at the moment?

The electric should be able to have the same if not higher top speed, yet still be soooooooooooooooooo much faster out of corners.

Glad you liked it though :thumbsup:

I'm using standard which is 15 pinion and I think 45 or 46 spur, not sure what final drive that would give though?

The straight was pretty long at Sutton and the top nitro's had more top end than at other tracks I've seen them like Oz, so think that may be the reason? Think they were only getting an average of 7 or 8 minutes per fuel tank from what I saw too?

I'll see how it goes at other tracks but want to play safe on temps where possible!

[HarlowS]

I run a 14t on a 2650kv and have ran a 15t so you should be good to move up to a 16 to try, the lower kv motor wont be running as hot either so you should be good for a bit more top end. :thumbsup:

[DaveG28]

Nice one, will get hold of some pinions (and more batteries), gotta say really loved running 8th scale, and there seem a few championships that let them run so all good!

Hopefully more and more people will run them as time goes on!

[DaveG28]

Stuart are you running the losi? If so what rideheight do you go for? Mine sits with quite a lot of plunge on the driveshafts at the moment?

[Marvin]

Differential Ratio: 3.3
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 15
Total Voltage: 14.8
Motor KV: 2100
Tire Diameter (inches): 4.5
Tire Ballooning (inches): 0.1
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 3.07 : 1
Total Ratio: 10.12 : 1
Tire Circumference (inches): 14.77 inches (375.04 mm)
Total Motor Speed: 31080 RPM
Vehicle Speed: 42.94 mph (68.98 km/h)
Effective KV Value: 2100
KT constant: 0.64 oz-in/A

Here are the results from THE calculator. Is Sutton an absolutely massive track or something? You are geared for a higher speed than I was with my Losi, and I was outpacing nitros down the straight (only just though).

If so, go with a 16T pinion and something like a 48T spur if possible. This should keep you as fast. The main problem with gearing up, is that, it heats up everything, and run time is reduced.

Differential Ratio: 3.3
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 48
Pinion Tooth Count: 16
Total Voltage: 14.8
Motor KV: 2100
Tire Diameter (inches): 4.5
Tire Ballooning (inches): 0.1
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 3 : 1
Total Ratio: 9.9 : 1
Tire Circumference (inches): 14.77 inches (375.04 mm)
Total Motor Speed: 31080 RPM
Vehicle Speed: 43.9 mph (70.51 km/h)
Effective KV Value: 2100
KT constant: 0.64 oz-in/A

Here are the results from the set-up I suggested. It's only 1mph more, but it should be enough. Try the 16T pinion on it's own first though.

I'm thinking it could be the Losi battery. The true C rating on those is only about 15C, so it won't be capable of providing the sort of current you're after. If you have another 4S lipo to try (like a Flightpower), give that a go instead, and see if there is any difference. I just can't believe you are outpaced down the straights by the nitros on that set-up.

Oh, and for ride height, start with arms level, and if that's not quite enough, go for driveshafts level.

[DaveG28]

The top end was by no means a disaster, I mean I qualified 2nd and led the A final until taking the car off so it was plenty quick!! (and as anyone who knows me from 10th will say I ain't that good a driver!), just I'd say maybe a couple of the nitro's had a little more top end!

Hard to say how long the straight was, but maybe not far off double the length of the straight at the Oz BCL round? Also not sure what Nitro's normally get out of a tank, but they were only getting 7/8mins on it?

I'll get a pinion to try and see what heat difference it makes! I'll also check the rideheight later!

[Matt Alcock]

the straights about 50 m long.

[Marvin]

Hmm, about the same length as the main straight where I go. I suppose if you don't feel it's a problem, then use the old adage 'If it isn't broken, don't fix it.'

7/8 mins is about normal to be honest. Some can get about 10 minutes at an extreme push, whilst others can barely get 6 minutes. It all depends on the engine and tuning (something we don't have to worry about, though something you never had to worry about:D).

Congrats on the excellent 1st result though! Plenty more to come too I'd have thought...

[HarlowS]

Nope runnin an RC8, pretty much sticking with driveshafts level at the moment, occasioally just below.


Stuart are you running the losi? If so what rideheight do you go for? Mine sits with quite a lot of plunge on the driveshafts at the moment?

[glypo]

My Hyper 9 (home made conversion) was awesome for battery life at the Neo. Even in the 10 minute semi (I was standing next to Maifield - awesome) I drew less than half capacity, so can easily hit 20-30 mins.

I am running a Neu 1512 2.5D, Tekin R1 Pro and two TrakPower 4900mAh (30C). The cells are awesome, 30C unlike the less powerful 5400mAh. I think being lower grip though Neo was kind. I have yet to try on a normal UK track.

Soon I hope :thumbsup:

[Marvin]

My Hyper 9 (home made conversion) was awesome for battery life at the Neo. Even in the 10 minute semi (I was standing next to Maifield - awesome) I drew less than half capacity, so can easily hit 20-30 mins.

I am running a Neu 1512 2.5D, Tekin R1 Pro and two TrakPower 4900mAh (30C). The cells are awesome, 30C unlike the less powerful 5400mAh. I think being lower grip though Neo was kind. I have yet to try on a normal UK track.

Soon I hope :thumbsup:

Aren't the 4900mAh Trakpowers 25C, not 30C? Though they, like all Flightpowers, have a 35C climbout and a 50C maximum discharge, so it's all good.

Having seen the Neo track I would say on a normal UK track, you won't be getting 20 minutes, though I could be wrong (it has been known :D).

The fact that the Hyper 9 is light also helps, it's good to see someone run a PROPER set-up. Good quality batteries, fantastic motor, and a capable ESC, lovely.

You'll have to post some pics on here. What did you do for weight distribution?

[glypo]

Yup sorry you are right indeed.

25C with 35C peak and 50C burst. I've been looking at some FlightPower 30C cells for a new plane I am building so had 30C stuck in my head. Either way the 5400mAh is the lesser choice, I got one bit right at least lol.

TrakPower 2S 4900mAh - 25C Cont. (122A) - 35C Peak (172A) - 50C Burst (245A)

TrakPower 2S 5400mAh - 16C Cont. (86A) - 25C Peak (135A)

I believe I went for the best equipment for the job. The Enderland cells in the TrakPowers are awesome, and actually deliver close to their ratings, unlike a lot of these totally fictitious ratings others give their cells and people blindly believe. The Neu is obviously amazing. Very efficient and very quick! It made me chuckle last night watching RC Racing TV seeing Adam Skelding mentioning motor temperatures at the Neo. I don't think mine got warm?

The Tekin R1 Pro is awesome too. Without a doubt one of the best brushless ESC's ever made. It even out-rates the RX8 that Tekin have developed. Obviously it lacks the convenience of a nice heatsink and a BEC capable of handling the voltage, if the RX8 was out at the time I would have got one, but for a 1/10th ESC the R1 Pro is better than nearly all 8th ESC's, crazy.

I agree 20 mins on a higher grip track wouldn't be likely on a normal UK track. I will have to get racing it soon and find out for sure though! The Hyper 9 is great too. As you say, it weighs next to nothing. The diffs are smaller than normal 8th etc, it lends itself very well to leccy. The 9E came out a couple of weeks after the Neo, typical!

I will be doing a small project report on my website, until then though you can see photos of it here:

http://www.facebook.com/album.php?aid=66977&id=516994274&l=8340b0d696

I realise cells aren't in the shots, but they were obviously put on the empty side of the chassis. Balanced very well :)

Oh I have to include a photo of it in cam-car mode though :lol::

http://img40.imageshack.us/img40/5641/img7537.jpg

[Marvin]

Flightpower have announced a new range of LiPOs, to replace the Eon series. The EonX ranges. These can be charged at 5C safely, though there is no charger to charge at 25A yet!

I've recently got some Hyperions which have the 5C charge rate capability too (though they've been out slightly longer than the Flightpowers).

I think 2 or 3C is probably enough though!

The MMM is a great ESC too, though many people still run R1s, the MMs etc, as they are rated for 3S with BEC, so are capable of about 4-5S without.

I assume you've seen the 9E pics. I like the layout in your car, though Hobao's kit is nicer (the centre diff at the back is a good idea, as the electrics tend to be front heavy), though I would say that, as I have one!

Nice work on the motor mount though, much better than I could even conceive doing, I'm still a bit crude on the ol' CAD.

I recognised the shell straight away, I enjoyed your footage of the Neo, though the camara mount may need a Mark 2 made that doesn't fall down :lol:

[glypo]

I agree the 9E looks awesome. The main reason I got a Hyper 9 was so I could convert it to the official 9E (at the time of the Neo the 9E wasn't out). However I was so very impressed with the handling of the car at the Neo I am not going to change.

MMM is indeed awesome. A little on the large side though, but if that's its only downside they have done great. I am glad to see Castle making it big in the racing scene (even if it is 1/8th). It's about time people realise some of their favourite "racing brands" mightn't offer the best electronics. My R1 Pro looks lost on an 8th though. Still, 48 FETs in such a tiny beast is still insane, the thing amazes me.

Oh yes, we do have much better video from on-board! The video we uploaded was one of the practice days and we hadn't got it working quite right. I just need to edit the video where the cam is working :):)

[Marvin]

I agree the 9E looks awesome. The main reason I got a Hyper 9 was so I could convert it to the official 9E (at the time of the Neo the 9E wasn't out). However I was so very impressed with the handling of the car at the Neo I am not going to change.

Having seen your conversion, I wouldn't have bothered changing it either, it's very similar to the 9E anyway.

MMM is indeed awesome. A little on the large side though, but if that's its only downside they have done great. I am glad to see Castle making it big in the racing scene (even if it is 1/8th). It's about time people realise some of their favourite "racing brands" mightn't offer the best electronics. My R1 Pro looks lost on an 8th though. Still, 48 FETs in such a tiny beast is still insane, the thing amazes me.

Castle are actually releasing a Mamba Max Pro. Rated for 6S (I think, or maybe 4S, not too sure), 100A continuous (a real figure, not the inflated ones that LRP/Nosram etc use), sensored, and in a case the size of a normal 1/10 ESC.

Tekin and Castle appear to have the 1/8 market nailed between them. None of the other stuff comes close.

Oh yes, we do have much better video from on-board! The video we uploaded was one of the practice days and we hadn't got it working quite right. I just need to edit the video where the cam is working :):)

I'd like to see it. Looking forward to it!

[jimmiprice]

I have a couple of questions regarding my brushless car fellas, maybe someone here can help.
Ive built a Losi 8ight 2.0 E and its awesome, i race 8th scale nitro but have built a brushless car for practise and to see what all the hype is about. Spec is below.

Losi 8ight E 2.0
Mamba Monster Max speedo
Losi xcelerion 1700kv motor
6s 5000mah 30c Lipos
45t plastic spur
12t pinion

I initially built the car and fitted the 15t pinion, it was awesomely quick undriveable to be honest. However the motor seemed to be getting a little warm over 6 minute runs, speedo and lipos where fine though. I then changed the pinion to 12t which using the rc monster website converter gave the theoretical top speed just over 40mph which i though was correct. Ive ran the car since and im well happy with the speed (it will do any nitro car top end and smoke them off the bottom) the runtime is also excellent with 25 minutes the most ive ran it for and it was just starting to slow off ut wasnt anywhere near the lipo cut off. I do have one issue and that is still that of motor temp, theoretically the gearing should be right the lipos arent really getting warm and the speedo is cool too. Ive ordered a motor heatsink which should help but i think the motor is still getting too warm (it was 170 farenheit after a 15 minute run). Question is do i gear down to a 10t or 11t pinion or is it getting too hot as its undergeared ? Is there any sure fire way of telling ?
Jimmi.............

[electric]

I have a couple of questions regarding my brushless car fellas, maybe someone here can help.
Ive built a Losi 8ight 2.0 E and its awesome, i race 8th scale nitro but have built a brushless car for practise and to see what all the hype is about. Spec is below.

Losi 8ight E 2.0
Mamba Monster Max speedo
Losi xcelerion 1700kv motor
6s 5000mah 30c Lipos
45t plastic spur
12t pinion

I initially built the car and fitted the 15t pinion, it was awesomely quick undriveable to be honest. However the motor seemed to be getting a little warm over 6 minute runs, speedo and lipos where fine though. I then changed the pinion to 12t which using the rc monster website converter gave the theoretical top speed just over 40mph which i though was correct. Ive ran the car since and im well happy with the speed (it will do any nitro car top end and smoke them off the bottom) the runtime is also excellent with 25 minutes the most ive ran it for and it was just starting to slow off ut wasnt anywhere near the lipo cut off. I do have one issue and that is still that of motor temp, theoretically the gearing should be right the lipos arent really getting warm and the speedo is cool too. Ive ordered a motor heatsink which should help but i think the motor is still getting too warm (it was 170 farenheit after a 15 minute run). Question is do i gear down to a 10t or 11t pinion or is it getting too hot as its undergeared ? Is there any sure fire way of telling ?

Jimmi.............

the motor can get hot from undergearing (causing it to overev) and overgearing it. what pinions do you have? if you have a range from 10-15 just test to see what happens when you gear down/ up and measure the temps :)

[Marvin]

The Losi motors will run hot anyway, they aren't as efficient as the Neus, the CC Neus, Hackers, Lehners or Medusas, so will produce more heat due to wasted energy.

As electric says, try other gearing options, gear down 1st, then if this makes temps worse, try going to a 13t and work from there.

[jimmiprice]

Ill try experimenting with gearing over something like 3 minute runs. I know wrong gearing be it low or high will heat the motor. Should i still be looking for a thoretical 40mph speed even on 6s or does it change. Also what sort of heat tempo should i be looking at as being safe for the motor?
Thanks for the answers, the buggy is really good and i am impressed with it.
Jimmi.............

[Marvin]

Always look for 40, no matter what the voltage.

[DaveG28]

Finally got a final today, 15 mins on grass (East Shrewsbury), did it with no battery change on a 4s 5000 battery and finished ok, didn't do any warm up or slow down laps and drove a bit "sensible" (cut down on the braking!), finished with 3.3v left in each cell. Was geared 14/45.

Happy I can get 15mins out of one pack, means I only need one change for even a 30 min final!

[Marvin]

Your track obviously requires either less throttle, or you are just a smoother driver than I am, but that's an impressive run time for a 4S 5000 pack. I have had to move to 6S 6100mAh to get clearly over 20 minutes - and you can imagine the weight involved with that battery!