How much to convert

[David W]

I like the idea of this brushless job, sick of my nitro engine!
I was wonderind how much it costs to convert?
I have a nitro hyper 9 at the moment so have servoes and transmitter and the usual stuff for a nitro. Has anyone converted one of these yet?
And has anyone raced against nitro buggies? what do they compare like?
Thanks!

[electric]

Originally Posted by David W

I like the idea of this brushless job, sick of my nitro engine!
I was wonderind how much it costs to convert?
I have a nitro hyper 9 at the moment so have servoes and transmitter and the usual stuff for a nitro. Has anyone converted one of these yet?
And has anyone raced against nitro buggies? what do they compare like?
Thanks!

£200 for the esc and motor
£75-100 on the conversion kit
£50-£150 per battery (4s)

quite alot all in all

[Marvin]

Originally Posted by David W

I like the idea of this brushless job, sick of my nitro engine!
I was wonderind how much it costs to convert?
I have a nitro hyper 9 at the moment so have servoes and transmitter and the usual stuff for a nitro. Has anyone converted one of these yet?
And has anyone raced against nitro buggies? what do they compare like?
Thanks!

Hobao are releasing a Hyper 9 conversion kit (as seen on Neo-Buggy) and I have already owned it. It is a nice conversion, though you will have to do your research on the bits to go into it. Try RC-Monster for research.

Depending on how long your local track's finals are, you may need more expensive, and larger capacity batteries than electric mentioned. For example, my first conversion, I got 12 minutes run time at a push on a track, which was with a 14.8V 4350mAh Lipo. That packs potential power is (14.8V * 4.35) 64.38Wh. Now, to get 20 solid minutes (so aiming for 22) I need a larger battery, I tried 2 18.5V 3300mAh packs in parallel (capacity * 2, voltage remains the same), which is 122.1 Wh, but due to the extra weight I can only manage 20.5 minutes, which is cutting it fine.

Now I'm trying a lighter set-up with more potential power, one 22.2V 6100mAh battery for 135.42 Wh, which theoretically, according to my previous set-ups, should be good for about 22.8 minutes.

In short, you do need to experiment, and remember that run time depends (with the same set-up otherwise) on voltage AND capacity.

I have raced against nitro buggies, and you will find that the electric will be quicker out of corners, and provided its balanced, will jump better (shorter run-up needed). They need a smoother driving style, and a lot of throttle control, particularly when it is low grip, as you will end up going in a circle if you are throttle happy.

That's me done...

[BagofSkill]

The new RRCi has a race report from Nene Vally where in the 20 min final electric buggies finished 2nd and 3rd, they were 1-2 but needed to stop at the end for a precautionary battery change apparently. So based on that and results from the neo09 it seems they're pretty competitive when you have the right setup, and once you've bought in, the running costs should be almost zero.

[DaveG28]

I've run mine twice now (Losi 8E 2.0) having never run 8th previously, and first time out qualified 2nd at a nitrocross round, and second time out TQ'd at a club meet at NNRC.

Given my 10th results I would assume that means the cars are plenty quick!!

I haven't run a full final yet, did 11mins at the nitrocross (only had one battery) without issue and leading throughout, and didn't start the final at NNRC due to wussing out on weather. My only concern is how my temps will hold up over 20+ mins, feels very hot after 7 or 8 but don't have a temp measurer, or any idea how temperature would likely increase beyond 10 mins??

Also, may depend on the conversion but the losi is a very slow battery change!!

[electric]

Originally Posted by DaveG28

I've run mine twice now (Losi 8E 2.0) having never run 8th previously, and first time out qualified 2nd at a nitrocross round, and second time out TQ'd at a club meet at NNRC.

Given my 10th results I would assume that means the cars are plenty quick!!

I haven't run a full final yet, did 11mins at the nitrocross (only had one battery) without issue and leading throughout, and didn't start the final at NNRC due to wussing out on weather. My only concern is how my temps will hold up over 20+ mins, feels very hot after 7 or 8 but don't have a temp measurer, or any idea how temperature would likely increase beyond 10 mins??

Also, may depend on the conversion but the losi is a very slow battery change!!

what gearing motor e.t.c because i have the 1.0 8ight B converted and temps on the medusa motor seem quite high (170F but i have geared down now because i used to run 16/48). get yourself a cheap 2nd chand temp gun some go for around £10 on here and other forums

[AmiSMB]

Originally Posted by electric

what gearing motor e.t.c because i have the 1.0 8ight B converted and temps on the medusa motor seem quite high (170F but i have geared down now because i used to run 16/48). get yourself a cheap 2nd chand temp gun some go for around £10 on here and other forums

I have a Losi 8T Tekno conversion with the Tekin RX8 and T8 2250kv Truggy motor and it was very quick on 13/48 but I could only do 14mins on a MaxAmps 4s 8000mah so went to 13/50 and still had plenty of top end and can do just under 20mins with the same pack. Am going to go with a T8 1550kv and go up to 6s 5000mah to get efficency with even more speed so hopefully will last longer.

[DaveG28]

Originally Posted by electric

what gearing motor e.t.c because i have the 1.0 8ight B converted and temps on the medusa motor seem quite high (170F but i have geared down now because i used to run 16/48). get yourself a cheap 2nd chand temp gun some go for around £10 on here and other forums

I run the losi 2100 motor on 4s 5000 cells. Gearing 15/45 (don't know about final drive ratio?).

I'd get a temp gun but how do temps extrapolate. Eg if it 120 after say 7 mins what does this suggest it will be at 10 mins, do temps level out?

[Marvin]

Originally Posted by AmiSMB

I have a Losi 8T Tekno conversion with the Tekin RX8 and T8 2250kv Truggy motor and it was very quick on 13/48 but I could only do 14mins on a MaxAmps 4s 8000mah so went to 13/50 and still had plenty of top end and can do just under 20mins with the same pack. Am going to go with a T8 1550kv and go up to 6s 5000mah to get efficency with even more speed so hopefully will last longer.

I doubt that you'll get that 20 minutes with that new set-up, 14.8 * 8 = 118.4 Wh, 22.2 * 5 = 111 Wh, so your new set up has less potential power, and it won't be that much more efficient. Also, if you are getting extra speed, your run-time will be reduced anyway.

You may have to do similar to me, gear for a touch under 40, and have a ~6000mAh 6S pack to get 20 minutes.

[AmiSMB]

Originally Posted by Marvin

I doubt that you'll get that 20 minutes with that new set-up, 14.8 * 8 = 118.4 Wh, 22.2 * 5 = 111 Wh, so your new set up has less potential power, and it won't be that much more efficient. Also, if you are getting extra speed, your run-time will be reduced anyway.

You may have to do similar to me, gear for a touch under 40, and have a ~6000mAh 6S pack to get 20 minutes.

Yes I have less potential power but I am dropping the kv of the motor and increasing the voltage which will mean I am going to be pulling a lot less current out of the batteries. I am currently geared for 2250kv motor on 4s for 33.8mph but the 1550kv motor on 6s will be 35mph on the same gearing and at the higher voltage it will be running cooler as well due to the lower current draw of lower power motor and the use of higher voltage. Well the only real way to see is to put it into the car and give it a go. I have nothing to loose!

[Marvin]

Originally Posted by AmiSMB

Yes I have less potential power but I am dropping the kv of the motor and increasing the voltage which will mean I am going to be pulling a lot less current out of the batteries. I am currently geared for 2250kv motor on 4s for 33.8mph but the 1550kv motor on 6s will be 35mph on the same gearing and at the higher voltage it will be running cooler as well due to the lower current draw of lower power motor and the use of higher voltage. Well the only real way to see is to put it into the car and give it a go. I have nothing to loose!

I'm going to have to disagree unfortunately. True, your new set up wold draw less current, but, you have it geared for a higher top speed, which increases current draw. Also, the efficiency gains from the lower V to higher V are very small, and don't make enough difference IMO to counteract the lost potential power. Obviously give it a go, as experimenting is good, but I do think you'll be a bit disappointed.

[AmiSMB]

Originally Posted by Marvin

I'm going to have to disagree unfortunately. True, your new set up wold draw less current, but, you have it geared for a higher top speed, which increases current draw. Also, the efficiency gains from the lower V to higher V are very small, and don't make enough difference IMO to counteract the lost potential power. Obviously give it a go, as experimenting is good, but I do think you'll be a bit disappointed.

I did say that the gearing stays the same but due to the increase in voltage this will give me a higher top speed (all in theory of course). So as I am dropping 700kv I will also be drawing less current than I was using the 2250mah and should be drawing less current as I am upping the voltage as well. As I said we shall see what happens when it arrives. Maybe when they make higher capacity cells which are not silly amounts of money then we can all stick to a decent 4s setup. I am initially going to test with 3 x 5200mah 2s Vampire racing packs and 3 x 5000mah 2s Demon (now non brca legal) packs. If this is good then I will look at the highest capacity 6s packs available which at the moment seem like the Hyperion G3 VX 6500mah pack once they have been announced and if they fit the battery tray

[DaveG28]

Hat would be a reasonable temp at the end of a 5min run guys?

[Marvin]

Originally Posted by AmiSMB

I did say that the gearing stays the same but due to the increase in voltage this will give me a higher top speed (all in theory of course). So as I am dropping 700kv I will also be drawing less current than I was using the 2250mah and should be drawing less current as I am upping the voltage as well. As I said we shall see what happens when it arrives. Maybe when they make higher capacity cells which are not silly amounts of money then we can all stick to a decent 4s setup. I am initially going to test with 3 x 5200mah 2s Vampire racing packs and 3 x 5000mah 2s Demon (now non brca legal) packs. If this is good then I will look at the highest capacity 6s packs available which at the moment seem like the Hyperion G3 VX 6500mah pack once they have been announced and if they fit the battery tray

When I say 'geared to a higher top speed' I mean gearing should be changed to suit the motor and battery (plus the weight etc). As you have a higher top speed, it is the same effect as gearing higher. Also, you say you have less current draw - which is true, but you also have less capacity to draw that current from, 5 Ah instead of 8 Ah, hence my earlier Wh comparison.

You won't need a 6500mAh - that'll be stupid weight, and those Hyperion G3 cells aren't light either. Higher C rating = more weight, which is why my new set up is 'only' 18C continuous, but which is still enough (109.8A continuous), predicted max current draw (burst, under heavy acceleration, is about 105A), and the burst capability (30C) is 183A.

Originally Posted by DaveG28

Hat would be a reasonable temp at the end of a 5min run guys?

My understanding is that the ESC should be no more than about 170-190F, and the motor shouldn't really be more than 160F, ish (at 190-200F the motor begins to, let's say, not perform quite as it's meant to).

[DaveG28]

Originally Posted by Marvin

My understanding is that the ESC should be no more than about 170-190F, and the motor shouldn't really be more than 160F, ish (at 190-200F the motor begins to, let's say, not perform quite as it's meant to).

Cheers, any idea what a good 5min temp would be as an indicator for running up to a half hour final. As in if my temp at 5 mins was 140f at the motor would it likely level off or would it suggest a problem brewing (eg it would keep rising above 160f), or is there just know way of knowing without trying it??

[electric]

Originally Posted by DaveG28

Cheers, any idea what a good 5min temp would be as an indicator for running up to a half hour final. As in if my temp at 5 mins was 140f at the motor would it likely level off or would it suggest a problem brewing (eg it would keep rising above 160f), or is there just know way of knowing without trying it??

there isn't really any way of knowing i wouldn't have thought. if you are geared correctly temps will tail off and stay at a constant but if you aren't then temps will continue to rise

[Marvin]

Electric is right. There is no way we can tell from here. If the gearing is reasonable then there is no reason why it should continue to heat up (think of it a bit like an oven, once it's set to a certain temperature, it won't rise any more until you fiddle with its set-up).

[DaveG28]

Well, been out tonight and bought a cheap temp guage (hope it's accurate!) and popped down to stokes practice night:

Did around 11 mins on a battery, 4 min break to check everything and swap cells then a further 13/14 mins on the new battery, no long straight but was deliberately braking much harder than normal to generate heat, and came off with around 175f on the motor heatsink (motor itself may have Been a little cooler). Esc either much cooler or couldn't get a good Reading.

Hoping that means I'll be ok, wouldn't have thought it would keep increasing much more after 20/25 mins, and it's a hot day!

One question, at the end I did a standing start and it didn't move, the pinion didn't move but it sounded horrible!? Kept running fine after that and with loads of start stops, could it be to do with it being sensorless!??

[Marvin]

It could just be a bit of cogging, but it'd be worth checking the mesh too (could also cause temps to rise).

Those temps sound a bit high for my liking to be honest, try gearing down one tooth on the pinion, or better yet, go up one or two teeth on the spur.

[DaveG28]

Originally Posted by Marvin

It could just be a bit of cogging, but it'd be worth checking the mesh too (could also cause temps to rise).

Those temps sound a bit high for my liking to be honest, try gearing down one tooth on the pinion, or better yet, go up one or two teeth on the spur.

Well they'd shortened the track for 10th and I was not getting near top speed in one spot, might that be the cause (as in the gearing maybe need your suggested adjustment on that track, but not others with longer straights?)?

Am going to sort some more pinions/apurs anyway and try it, may a lower kv motor help too?