Speed Runners ~ How Fast Did You Go Today?

[LibertyMKiii]

Ok fellas @LibertyMKiii @The Donut Man @jondilly1974 @rotauq had an issue today and I can't figure it out. Pass started great got just past me and motor made a weird sound so pulled off. Thought maybe a Hoon finally gave but nope all good, thought maybe diff out but as you'll see in the log nope RPMs stayed even so I'm not sure what the hell happened. Will take a while to get video for you guys to watch and listen but I'm stumped. Made another pass but not a full pass but still was hard on it and didn't do it again so I have no clue. Also my ripple is higher now all of a sudden then without the Ripple Killer cap pack so going to check solder joint but I need help figuring this one out. Here's log below, so pissed as without the issue it would have been my 140 pass for sure log looks great to me. I had issue right after it passed me at 130mph appreciate any and all suggestions and help guysView attachment 145277

Looks like you may still have smoothing turned on? The settings at the top you can disable the graph smoothing.
Nothing really stands out.... When something sounds funky usually it is either the motor gear mesh you gear or the diffs.
The RPMs were gaining the whole time, so its hard to say.

 

[rotauq]

Video will have to tell us about the sound.

A lot of smoothing going on there indeed. Vdrop looks extreme 9V in a second. Could be a bad battery

 

[Mr.Duke]

Guys.... I can’t stress this enough times.... if you are using smoothing of any sort on your data logs you are wasting your time looking at averages and not raw data. There’s no reason to have smoothing on if you are attempting to diagnose a runs performance and only hides the real data in exchange for pretty lines

 

[Edough13]

Looks like you may still have smoothing turned on? The settings at the top you can disable the graph smoothing.
Nothing really stands out.... When something sounds funky usually it is either the motor gear mesh you gear or the diffs.
The RPMs were gaining the whole time, so its hard to say.

Mesh is good, didn't change gearing and diffs are good as well. It almost sounded like it cut out on me.

Video will have to tell us about the sound.

A lot of smoothing going on there indeed. Vdrop looks extreme 9V in a second. Could be a bad battery

Packs seem fine both have even voltage after the pass nothing that would suggest an issue. I'll take smoothing off and post another pic of the log.

 

[ABabyEater]

Mesh is good, didn't change gearing and diffs are good as well. It almost sounded like it cut out on me.

Packs seem fine both have even voltage after the pass nothing that would suggest an issue. I'll take smoothing off and post another pic of the log.

Resting voltage evening out may not necessarily rule out the possibility of the packs being bad. If you can, check IR, and if you are confident in your setup (or in a different car) charge them, run them, and check voltage as soon as possible off a large current draw. Batteries can stabilize, recover voltage, and even partially "self balance" after letting off from extreme stress. It's not likely that they are bad if they seem fine at rest, but if you want to really check for sure, it needs to be done before they can recover.

 

[Edough13]

Ok here's the log with no smoothing @Mr.Duke but doesn't look much different video is done but my internet blows so will take atleast couple hrs to upload.

 

[Mr.Duke]

Ok here's the log with no smoothing but doesn't look much different video is done but my internet blows so will take atleast couple hrs to upload.View attachment 145281

Smoothing threw the following readings off:

minimum voltage off by +0.9volts (that’s a pretty big difference)

total voltage off by +0.2v

ripple off by +0.46v

HP reduced by -0.371hp

RPM reduced by -548rpm

 

[K-BASH]

1st pass on new setup.far from a clean pass..good 1st # thou.tied my pb 1st run.go for a pb little later

 

[LibertyMKiii]

1st pass on new setup.far from a clean pass..good 1st # thou.tied my pb 1st run.go for a pb little later

It has a lot more left in it. Your voltage drop was very minimal and current isn't that high yet!
Time to gear up

 

[rotauq]

Ok here's the log with no smoothing @Mr.Duke but doesn't look much different video is done but my internet blows so will take atleast couple hrs to upload.View attachment 145281

Next time, could you take pictures starting from 0 rpm? and the right scales in the picture too. With my colorblindness it's hard to see which is which when i can't see where they originate.

It still looks like you throttle up hard at ~16k rpm, acceptable amp incline, but the voltage drop really steep (could be the high ripple. Not surprised tough of the ripple if you cappack would have disconnected)
There is no thick line representing the LVC. It's turned on, right?

If it didn't happen again, maybe it was just a rock or something that you caught up during your run and grinded at the pinion/spur (you specifically related the sound to the motor) and got out before you started checking stuff.
Still could be a motor bearing or something.

 

[rotauq]

Guys.... I can’t stress this enough times.... if you are using smoothing of any sort on your data logs you are wasting your time looking at averages and not raw data. There’s no reason to have smoothing on if you are attempting to diagnose a runs performance and only hides the real data in exchange for pretty lines

I agree raw data equals accuracy and you always start with those. But smoothing does make sense when you also wanna see a better representation of the rpm curve, mean makes a brain friendly trendline

 

[Edough13]

Next time, could you take pictures starting from 0 rpm? and the right scales in the picture too. With my colorblindness it's hard to see which is which when i can't see where they originate.

It still looks like you throttle up hard at ~16k rpm, acceptable amp incline, but the voltage drop really steep (could be the ripple, not I am not surprised of the ripple if you cappack would have disconnected) There is no thick line representing the LVC. It's turned on, right?

If it didn't happen again, maybe it was just a rock or something that you caught up during your run and grinded at the pinion/spur (you specifically related the sound to the motor) and got out before you started checking stuff.
Still could be a motor bearing or something.

Don't think it was a rock either sounded like the motor almost cut out or lost power. And no I don't run LVC for speed runs as I've been suggested not to so LVC doesn't kill my run midway. Sorry can't apparently take a picture of log right first it needed smoothing off now need all graphs and RPMs at 0 shown. I didn't know it was so important to show areas not during the main part of run or where the issue I asked for help occured as I assumed that's what was important to look at.
Ok damn video finally uploaded so tell me what you guys think being able to hear what happened.

 

[rotauq]

"Prrrrrrrr-auw", hard to hear but yeah. D-sync was only a 6 pole problem, it's still your 4060CM-2080 right?

Bearing, Rotor imbalance? I would probably open up the motor. Some of the kevlar might have been scratching the stator.

 

[Edough13]

"Prrrrrrrr-auw", hard to hear but yeah. D-sync was only a 6 pole problem, it's still your 4060CM-2080 right?

Bearing, Rotor imbalance? I would probably open up the motor. Some of the kevlar might have been scratching the stator.

Yes still the 4060-cm 2080kv. I'll have to open it up and look later after my kids baseball practice. Sorry for my ignorance what is the stator so I know what I'm looking at? So disappointed though as that would have been a PB pass, my best pull on 8s so far and then blah

"Prrrrrrrr-auw", hard to hear but yeah. D-sync was only a 6 pole problem, it's still your 4060CM-2080 right?

Bearing, Rotor imbalance? I would probably open up the motor. Some of the kevlar might have been scratching the stator.

Also do you think it could have been that I changed timing? First pass at 137 I had it set to default 10, last pass at 138 I set it at 0 and then today I went back to default 10 to see if there was any significant change. Again thanks for the help and suggestions I appreciate it

 

[rotauq]

Yes still the 4060-cm 2080kv. I'll have to open it up and look later after my kids baseball practice. Sorry for my ignorance what is the stator so I know what I'm looking at? So disappointed though as that would have been a PB pass, my best pull on 8s so far and then blah

Also do you think it could have been that I changed timing? First pass at 137 I had it set to default 10, last pass at 138 I set it at 0 and then today I went back to default 10 to see if there was any significant change. Again thanks for the help and suggestions I appreciate it

Stator means, that does not spin round. When you pull out the rotor check the outer wrapping for scratches. If so, it's not necessarily bad, but if so i'd still swap the bearing even if they look good

I can't find on the specs if it's a D or a wye wind, but i am guessing it's a D. And then it's best to keep it on 0 deg. MMX8S/XLX2 have dynamic timing, so even if it likes 12deg it will go there. The default sets the starting point.
High timing means more heat and will not go fasters when pasts it's optimal point. If you go beyond it, it's not unlikely for heat differences between rotor&stator making them scratch each other. Often bad things are related to what you changed very recently, so it's definitely a plausible cause.

 

[Rush1791]

122MPH
Stretched typhon
Max5
TP 4070cm 2200kv
8s Ripplekiller
30P/34S
Slick grp tires 2Rear and 7Front
6s Cnhl 5000mah 70c
Ceramic bearings from eBay

 

[Edough13]

122MPH
Stretched typhon
Max5
TP 4070cm 2200kv
8s Ripplekiller
30P/34S
Slick grp tires 2Rear and 7Front
6s Cnhl 5000mah 70c
Ceramic bearings from eBay View attachment 145368

Need video for verification

 

[The Donut Man]

Need video for verification

What a warm welcome

Nice run @Rush1791! I also have that TP motor and I love it. Next time I update the leaderboard I’ll add you to the list

 

[LibertyMKiii]

Also do you think it could have been that I changed timing? First pass at 137 I had it set to default 10, last pass at 138 I set it at 0 and then today I went back to default 10 to see if there was any significant change. Again thanks for the help and suggestions I appreciate it

Might need more testing on the motor timing. My car lost about 5mph going to 0 degrees (d-wind motor)
Temp changes were very minimal so I went back to 10 degrees timing.

 

[ABabyEater]

122MPH
Stretched typhon
Max5
TP 4070cm 2200kv
8s Ripplekiller
30P/34S
Slick grp tires 2Rear and 7Front
6s Cnhl 5000mah 70c
Ceramic bearings from eBay View attachment 145368

Need video for verification

What a warm welcome

Nice run @Rush1791! I also have that TP motor and I love it. Next time I update the leaderboard I’ll add you to the list

Hehehe, nice run and welcome to the group! Don't worry about verification right away it's just nice to have a slot on the leaderboard verified or otherwise! If you aren't specifically competing with other members here, verification is absolutely not necessarily.