Tekin T8 1700kv truggy motor power delivery
 

Ok, will put it here as this is much more quiet forum without tons of posts a day



I feel a "hole" when going from low to mid RPMs.

Acceleration from standstill is great, topend is great but at the beginning of corner exit I feel a lack of power for a bit before the motor goes balistic

I played with Throttle profiles on RX8 and EXPonential on my radio but either I can feel the hole or too much power making it very hard to control the corner exit.

This is how it feels:

http://img.rcx.cz/tn.jpg



MBX5-T on BCE chassis with MBX6 shocks
RCM Slipperential
46/15 gearing (37.1mph) or 46/14 (34.7mph)
1700kv truggy motor
5S Lipo either 5000 Zippy Flightmax 30C or Hyperion G3 3300mah 35C/65C depending on weight and runtime I need
RTR weight 4280grams with Hyperion 4480grams with Zippy
Proline VTR tires


No drag brake
Brushless fwd/Brk mode
5S LVC
Current limiter off
Default neutral width
Tried Throttle profiles 3,4 and 5
Timing default 10

With Neu 1415/2.5D 1700kv the power delivery is linear

You are running the RX8 esc correct? And did you run the Neu 1415/2.5D on the RX8 or a different ESC?

Seems like a throttle signal problem or throttle profile problem...

Both with RX8. Other people have the same problem with RX8 + T8 motor combo

Same setting different motors. Neu works, Tekin does not. Well it works great of course but not with the linear power delivery and since i am very smooth on the throttle i can feel it.

i had the same problem when i had it in my rc8t....then the esc died and i ended up sending BOTH back to tekin to get the esc fixed and get the updated rotor fix....when i put the combo back it i actually had to gear it 2 teeth down ....(originally had it 17/46 to make up for the initial "pop")...not sure what they did to the esc or motor but it no longer has that "lag" in the initial throttle input...IDK...just my 2cents....

the lag is not in the initial input. it is when going from lets say 5000rpm to 8000rpm or something like that. I can feel it when exiting corner that the motor takes a bit more time to spool up.
Motor has then rotor.

Guess i will have to try it without the sensor wire.

If you don't already know, the Tekin T8 1700kv Truggy motor is a 1.5Y wind. Y winds respond to timing changes very well unlike D winds. Tekin originally sold the esc's preset with pretty high timing - making the Y winds rip more, and switched low timing on their later escs.

The 1700Kv Tekin Truggy motor is delta wound(2.5d - same as the similar 1515 Neu). Not as responsive to timing like a Y wound motor. This issue sounds more like a throttle profile or punch setting than timing to me (or dislocated rotor) - a dislocated rotor would make it feel like it has no "pop" coming out of corners or when trying to get over a jump with short run-up. The low end would be similarly affected, though. The sensor wire shouldn't be a factor at all.
For linear feel, the throttle profile "3" should be used, along with "0" on the throttle exponential. "4" and "5" throttle profiles should be rather aggressive/difficult regarding low-speed control(twitchy), and "numb" when beyond 50% trigger movement.

the pop is missing only when coming out of corners. from standstill it works well.

how can punch control help with this?

Disabling punch control (called current limiter in the Tekin software)would maximize corner exit "punch". I find that current limiting, while effective when taking off from a standstill, creates a "numb" or "muddy" throttle feeling in the mid range as you describe. The effect should be the same with a Neu motor as it is with a Tekin motor - this is where your stated issue gets wierd. The motors are dumb - only do what they are told by the esc.

I have punch control off.
exactly, it is weird, however couple fellow racers have the same feel - both run rx8 with 1700k T8 on 5S

Hmm. I run the same combo in my truggy (1700Kv truggy combo on 5s). I have never tried using another motor, but never noticed any "dead spots" in the powerband (I use throttle profile #2 and "95" CL setting).

will try that. I wish I had more time for playing with ESC settings.

Can you post your esc setup on here? Do you have a hotwire? If so what software are you running?

What Radio? Battery,etc?

Radio - DX3R
Battery - Hyperion G3 3300mah 5S 35C/65C or Zippy Flightmaxx 5000mah 30C/40C
I do have hotwire

RX8 settings:

No drag brake
Brushless fwd/Brk mode or FWD/BRK/Delayed Reverse
5S LVC
Current limiter off
Default neutral width
Tried Throttle profiles 3,4 and 5
Timing default 10

See my first post with the remaining info about my truck.
I use hotwire V3.25 -
i started with 3.24Beta that updated my ESC to fw198.
V3.25 after start displays a warning that some values are out of expected range.

5s 3300mah pack in a truggy will be pushed pretty hard on acceleration - this could very well be part of the problem(I would expect the same issue when using the Neu motor). I haven't used the Zippy packs, but would expect them to drop a bit under hard acceleration as well.

thats the thing - with Neu it is ok.
with my older setup - MGM160A + Neu 1512 2050kv on 5S Zippy it was the same balistic power from standstill to top speed

Wouldnt batteries be warm if pushed too hard? Both hyperions and zippys stay cool all day long

i will post here data from my new 150A eagletree that should arrive next week.

you might wanna re-read the last post. the zippy batteries are 5000mah and the 3300mah packs are the hyperion 3300 35c/65c packs.

I can read perfectly fine, thank you. While I haven't tried either pack specifically, I do use high quality packs, and race electric truggy and buggy frequently(have for years). I can push G3 5000mah 25c Hyperions, CTech and Enerland packs of the same rating in a hard race - and these packs are rated higher "on paper" and almost certainly "in the real world" than either of the packs in question. Besides - I didn't say this was the problem - I said it "could be" part of the problem. You might wanna re-read the post you quoted. :)

If batteries are "warm" or warmer than you feel they should be this is a sign of the pack on it's edge of comfort. The batteries all get warm but if it seems that the temp is higher than expected it's something you should consider.

C ratings have gotten a bit out of control. I've seen 40c rated packs get out performed regularly by "real" rated 25c packs....you get what you pay for.

or what you don't pay for...

it was 1:30am when i posted that comment. anything i say after 1:00am can't be trusted.:lol:

i agree with you about pack ratings. maxamps is the worst rating inflation offender imo. so, you have never tried a hobbycity pack? they are actually pretty true to their ratings from what i've seen. i have a couple flightmax packs that i use for my bl savage and my rustler vxl. for the price, they can't be beat. i wouldn't recommend them for hardcore racing, but for bashing or club racing, they fit the bill pretty well. try them out if you get a chance. you might be surprised. it would also be nice to hear some feedback since you seem to really know your lipos pretty well.:yes: your word about the hobbycity packs would have a lot more credit than mine as i have only been driving brushless RCs for about 18 months and i have only had 3 lipos before. i am curious to see how they compare to an enerland pack.:intello: