I want to convert my 8ight but I'm concerned about run time.
 

Hey everybody, I want to convert my 8ight 2.0 to electric and I'm worried about run time. There really isn't much interest in electrics at my local club track so realistically I'll be running with the nitro buggies. Last season there was one other guy who was running a converted rc8 and he dialed in his rig to just make it 20 minutes for the main race.

I remember he had to use 2 Lipos at once, and he needed at least 2 sets of 2 batteries to make it through all of the qualifiers and the main. My question is what do you think he was doing that worked? Was it gearing, battery selection, motor/speed controller?

I'm also a little confused on what I get to keep on the chassis. Do I use a center diff, brakes, and a clutch bell?

And then, what should I avoid in the conversion path? Any products work really well with the Losi 8ight 2.0 specifically?

Sorry for all of the questions, but the search returned A LOT of stuff that didn't really apply.

Go to this thread and search losi some guys have been converting since 2007

http://www.rctech.net/forum/electric...sion-kits.html

Most people are using 4s setups, and this is why they have a hard time making full mains with nitros. A lower Kv motor and higher voltage battery will be similar power but much more efficient.
I am unsure of the best way to convert your Losi, but I know many people use motor braking with a center spool, and some like to use a clutch, diff, and servo to keep the brake bias adjustable. Depending on the conversion that you choose will determine what type you have.

Losi sells a bolt on conversion kit for the 8ight. I just installed one on an 8T 1.0.

You can barely squeeze 20 minutes using a 1900kv motor on a 4S 5200 to 5800 mah battery. It all depends on the track and how power hungry your throttle finger is.

We race with the nitros at my home track but it's a 15 minute main which I easily make with a 1900 and 5100mah pack plus a few practice laps. I could just eke out 20 min with no practice and an easy finger.

I run a 1850kv nue on 4S 5000mah and can get 22-23 min but that is stretching it(I notice power starting to drop off last couple mins). I can make the same time on a 5S 4000mah setup which weigh the same. So it really comes down to how much battery(weight) you are willing to put in your car. Everyone says 5 & 6S are more effiecient and they are BUT it takes the same amount of battery weight to get-r-done! A 4s/5000 and 5S/4000 weigh close to the same as does a 6S/3300 which I have read on here it takes to make 20min. They are all within a couple of oz. I have found as already stated by others above most of it is in your throttle finger and track size. Hope this helps.

If you need 15 minutes or under, a 4S setup is probably adequate. If you are looking for 20 minutes, a 5 or 6S setup would be better due to the increased efficiency. The weight is the same, but the motor, battery and controller run cooler and more efficiently. A couple of the guys in our club have found the Tekin 1550 truggy motor on 5S is a very good buggy setup. I run the Tekin 2050 buggy motor with a 4S battery (5000 to 5500mAh) and 15 minutes isn't a problem for me.

Alright, thanks guys. I heard back from the guy with the RC8e (which is now converted to an electric dirt oval latemodel) and he told me he used a Mamba Monster 2600kv motor and speed controller with a 8000 mah Maxamps battery. He said this setup got him about 22 minutes of run time, and to me, it seemed like he had trouble clearing doubles and triples, particularly if they were out of corners.

I talked to a buddy at the local hobby shop, and he recommended a Mamba 2200kv system. Didn't talk about batteries.

What it sounds like everybody here is saying, is I need to keep the motor relatively small to prevent having to buy large (and expensive) battery packs. The track is pretty big, with some fairly large jumps, doubles and triples, an over/under section and a long strait with a double in the middle. Sorry I can't give measurements but we are putting the new layout in over the winter and it isn't set in stone yet. btw it is outdoors.

Would a 2200kv Mamba system be sufficient power wise and run time wise? It sounds like I won't be able to make the main with a 4s, so I will probably need one 5s 4000mah pack for the 20 min main event and at least one other 4s pack for the three 5 min heats. Now, we are trying to build the electric class up so the possibility of getting to run 15 min mains and 7-8 min heats is there as long as enough electrics show up. Will the above option work equally well in either scenario? Or am I looking at buying a large and small motor and swapping them out depending on turnouts?

I'm sort of taking this hit for the track. I really want to help it grow as it is a non profit club track. I figure the more diverse the cars we race are, the more likely we are to attract new racers. Eventually, it would be ideal to just worry about tuning for an electric buggy class but for now, the best I'm going to get is a mixed buggy/truggy electric class with a 15 min main. And that's best case scenario, worse is I'm running with nitro buggies for 20 min mains.

OK, so I had some info backwards, I learned the 2650kv motor is smaller than the 2200kv motor. :blush:

Is the 2650 motor going to work for me power-wise and runtime-wise, or am I better off going with the 2200kv system? A guy at the LHS told me I might run into some overheating issues with the 2650kv motor depending on how I gear for the track.

HUH!!!! :confused: What do you mean when you say the 2650 is smaller than the 2200, physically smaller like shorter, narrower or what???

The 2650 is the more powerful of the two and also the hungriest. It will give you shorter run times using the same packs as a 2200 would.

RPM= KV * V
39,220 = 2650 * 14.8
32,560 = 2200 * 14.8

You decide which is smaller.

Why does castle advertise this way then?

Why would you overpower a buggy and underpower a truggy/monster truck?

Sounds like you may be mistaking Kv for power. Just because one motor has a higher Kv than another doesn't make it more powerful. You wouldn't think of using a castle CM20 8000 Kv motor in an electric 1/8th scale (or even a 1/10th scale) just because it has a higher Kv.

The 2200KV motor has the capability for higher power output because it is longer and thus will produce more torque for a given current flow. Since the power output of these motors is limited by the amount of waste heat they can dissipate, and a bigger motor has more surface area to dissipate heat, the longer motor has a greater possible power output.

I was responding to this post.