2650kv in rc8
 

i just got my rc8 running with a 2650kv castle motor and a mmm with 4s 5000mah 30c lipos. and its geared 44/16 and does not seem all that fast. i was running it on the track and all the nitro guys where kicking my butt on the straight away but when it came to the turns and jumps i was doing ok cause it has a ton of bottom end power.

after about 15mins of drving i would bring it in and temp it and the motor was at 140 and the esc's fan was not even on so i did not check it.

do you think i could go up on the gearing and if so how far do u think i could go up. maybe a 19t pinion.

when i drove it nitro it had to have a 17t clutch bell to have any good power cause of the weird gearing the rc8 has. could that be why using a 16t pinion is not enough.


thanks.

oh yah my diffs are at 5-30-5

I would just try 1 tooth bigger at a time on the pinion until it feels right. Keep an eye on motor temp.

well at 15$ each i would rather just buy one and be right the frist time. i know its all about trial and error but i dont really want to spend 50$ on just 3 pinions.

I look at it this way: a $15 pinion is cheaper than a $250 motor (if you burn it up).

I would go up 2-3 teeth. It will load the esc not the motor. So if you've got low temps all 'round you should have some leway to do so. Just watch the temps on the esc.

The RC8 needs a pinion 3-4 teeth higher than most buggies because the f/r diffs are 43/10 instead of the more common 43/13.

Your 44/16 is about the same as running 44/12 in a car with 43/13 diffs.

Funny thing is, I think you should have no trouble running with the nitros @ 44/16... should be running like 45mph

That is what i was gonna say. :)
The speed should be comparable with superior acceleration vs. the nitros with this setup. Either your 30c batteries aren't cutting it, you have the wrong tires/setup for the track and can't 'hook up" on the straight, or maybe your towing a couple nitro behind you with some fishing line or something - the current setup should easily hang and adding a tooth or 2 ($10/each by the way) to the pinion should put the spank on the nitros in speed.
If you are getting your butt kicked on the straight with the setup you have, something is wrong somewhere.

Yeah, we all want that, but rarely it works out that way! :lol:

Well I know for a fact that this thing is not hitting 45mph. It does have tons of bottom end though cause there is a huge double that no one can make from a stand still. You have to hit the brum pretty fast to be Able to clear it and I can make it from a stand still but when it comes to the straight away I get killed.

I know everthing on the car is good cause I just rebuilt the thing with all new bearings. I think I'm going to try and put a 18t pinion on it and watch my temps. My boss is a big sponsered driver and knows a lot of people and he got me all the mod1 pinion so it's time for some trial and error

i had a similiar problem, but it didn't have anything to do with gearing or diffs or batteries.. i had to set the epa on my radio to 125% after a second calibration to get full throttle range

To tell you the truth I have not thought of that. I might have to go try that

dude omg i love you. not in the gay kinda way lol. i just looked at my radio and it was set to 65% throttle and i put it up to 100 went out and drove it and omg i just blow up a tire hahaha. i love this thing now. its got so much power its amazing hahhaha. thanks!!!!!!!!!!!!!!!!!!!!!!!!!!!!!:party::party:: yipi::yipi:

:lol:LOL:lol:

Kinda helps if you actually use full throttle.

glad i could help. :lol::lol::lol::party:

Did you reset the radio and then recalibrate it to the esc? If not you need to do that, just to be sure.

Could you post how the temps are after a race with the newly relocated power? Because I ran an RC8 with a 1512/2D on 4S on a regular MM last year and used 13/46 gearing. Just want to know if I was maybe undergeared. It was very comparable to nitros in top end, but obviously far superior overall :) Just got a MMM V3 for this year so should be even better.

i well be running tomorrow so yah i well get post temps tomorrow night.

yes i did reset the esc after i did that.

and also i think its time to lower the gearing a little lol. its retarted fast. like i blow up 3 tires today. and it was amazing my boss (nitro guy) cause in the parking lot i was able to pop up into a wheely and keep up for a while lol.

Any update on how the 2650 CC combo ran... curious about any heat issues and also the amount of milliamps been pulled

well with a gearing of 44/15 it gets to about 150 on the motor and has tons of power. in a few days im getting the tekno kit so i will see how that works out.

sounds good.... How much run time are you getting with the 5000ah pack

currently i get about 13-15mins

IIRC, the thing with 4 pole motors is that if they aren't under enough load (i.e. too low gearing) they will get hotter then they should be compared to the esc and battery. That would kind of explain your temps. What are your temps now all around?

i dont remember the temps on the battery and esc but on thursday or maybe tomorrow i will find out. - just waiting on my tekno kit to get here.

Really? This is the first time I heard of this. So if my Neu gets too hot, I should increase the pinion size and not decrease it? Or did I get that the other way around? :gasp:

i think what he is say is that if the motor is geared way to low it will over heat same as it being geared to high.

ok with the new tekno kit on the motor was at 130 and the esc's fan was not even on and the battery was not even warm. and that was after running for 16mins straight and drving it as hard as it could be drving. (was being driving by a pro lol seriously)

my gearing was 46/17 and had amazing amounts of power on both bottom and top.

im running a 17 cause you have to remember the rc8 uses truggy diffs so it needs to be geared higher to make up for it.

So that was using the clutch and mechanical brakes, right? Must be fast with that gearing.

yah clutch and mech brakes. and yah it was fast but still controllable cause of the clutch.

I would suggest a larger pinion (16-18) with the 1512 2D.

Finally got a vid of my RC8 that I have set up for speed. Have to shut her down with this gearing and voltage after about 10 minutes, but need to calm down about the same time too so it works. ;)

http://www.youtube.com/watch?v=iLwJD9DQ7FU

Vid of the tamer buggy coming up...set up for racing.

Joe, your dog is VERY brave!

That thing flys!

Can you give us any info on the Castle-Neu 1517?:whistle:

Hey Steve, are you still running the 2.5D? What was your gearing? I just got everything back together and took it for a spin at glenwood yesterday. First time out with the MMM. It was a blast, even on such a small track. I'm trying to get ready for Tillsonburg but I think a 16T might be too high. I'll have to do a more controlled test with about 3-5 mins on each pinion and measuring temps. See ya.

It's the 1800kv motor we're testing right now. :) Longer can, more torque...meant for larger/heavier vehicles or for those that don't want to go super fast on 4s..on 6s you can obviously make it "pretty fast".

Wow Joe that thing is a rocket.

Will get another vid soon...fully charge the pack (was almost dead in the video), put a 2200kv motor back in, and put the 1/8 rally tires on it. THEN you'll see a rocket.

Joe maybe you can answer this question why is the 2650 max voltage 16.8 when the Neu 1515/1.5d with a 2700 kv max is 22.2 volts.

A few reasons...one the 2650 is comparable to a 1512 series motor, not 1515 (that's the 2200). Being shorter, it can't handle the wattage that a 1515 can, and will have a tendency to overheat in 6s car applications...which we won't warranty. Second, those charts were made for the airplane guys originally...airplanes don't put the same strain on a motor that a car application does and they generally get much better airflow than an rc car/truck does....again, higher tendency to overheat if you don't know what you're doing. And lastly, but probably the most important (should have listed it first ;) ) is that at anything above 22.64v under load your motor is above the 60,000rpm limit...we want to minimize the risk of problems for our customers. In airplanes we RARELY need 60,000 motor rpms to get great performance...it is much easier to damage a motor from RPM in a car than a plane IMO. Only had one magnet fly apart in a plane (and it was my fault...ran my motor too fast in my pylon plane...but that's the point...all out speed)...can't tell you how many I've split in car applications, and on some of them I wasn't even trying to go fast. Demag the motor much easier in cars, and when that happens they speed up more and more til they come apart.

I must say I have to call you on this it is a bit of a sneaky change the 2650KV was originally listed on the site as 6s 22v the same as the 2200kv.

Reducing it to only 4s is a bit cheaky IMO - First time I've personally seem Castle do such a think.

I've already run mine on 5s.