- Thread starter
- #21
Totally agree. It's a learning experience and a growth cycle. What I thought was right at some point in my life might be how others see things. It's perspective.
Yup that was me asking you about a tire post 2 years ago. Thanks!
Jerold's Limitless Build
- Thread starter Jerold
- Start date
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Yup that was me asking you about a tire post 2 years ago. Thanks!
- Thread starter
- #22
New PB, Curb Rash and a Lot of Tuning Needed
I found a spot near my house that's straight and reasonably smooth. It's a neighborhood filled with bicycles, kids and dogs, but I figured we can share. The stretch is about 1200 ft long, but given the traffic situation I limited my self to about 500 feet. Batteries charged and off we go.
In this small stretch of well populated road I managed to get 50 MPH. The suspension is too stiff for that road, it was jumping around a bit, but it was controllable.
It's not great but it's a start.
The Setup
It's basically a detuned stock setup.
- 8S fully charged
- 27/34 pinion/spur center
- 13/43 front and rear diff
- 70% Max Power Adjustment @ ESC
- 5% THSPD(Throttle Speed Delay) set on radio
The THSPD(Throttle Speed Delay) makes a gentle roll into the power instead of punching it and getting all squirrely. Sort of an anti-hoon setting.
Oops
At the end of my runs I played a bit with some attempted some donuts which resulted in some curb rash. Oops. Since that is out of they I don't need to worry about it anymore.
OK it's not that bad. A bit of heat and some sandpaper will fix it. Or not, battle scars are sexy right?
Data Log
I've gone through the data log and it's clean. I'm not running a motor fan yet. The ESC and Motor temps are in check, but I can see that the motor is the limiting factor for thermal issues. I need to get a motor fan(s).
The current, watts, battery voltage and not ripple voltage all look fine.
However, I was only getting 40% of the power, except for that last spike, which is where I might have done a curb check. I'm also only running 500 feet and wondering if that might be an issue? But it's seems to be a plateau. So I'm thinking that's not it.
What the Math Says
I was able to run 50 MPH @70% Max Power (ESC), which means I should be able to do ~71 MPH @100% power. I checked this by using a gearing calculator and got ~90MPH @70% and ~128 @100%. Note I adjusted the kV to reflect my ESC restriction.
Something clearly doesn't add up. However, if I use my data log with 40% max power the 128 mph becomes 51 mph which is close enough to what I saw.
Why am I only at 40% and what and I missing?
Castle XLL2 ESC Setup
I've changed my setup a bit an wondering what others are running? I bumped the power up to 100% and moved the Max Power Adjustment to my CH3 (dial). We will see if that works.
Last edited:
- Thread starter
- #23
New PB, Sketchy Road and Sort of Fixing Hub Slop
I ran it again today and got to 61 mph! Now I only need to double that. This isn't that much faster but I learned few things from it.
Changing the ESC Max Power Adjustment controlled by my CH3 knob was brilliant. From the radio, I'm able to dial it down when I go to/from a run or just don't have the room for a full run. Or I can dial it up if I want have some fun and burn some tires.
The other change was removing the Throttle Delay from the RadioLink. It's a nice even gentle throttle curve and controls wheel spin but, it's a limiting factor.
With those two things I was able to get to 100% output on a few occasions.
Sketchy Road
The road I'm on is good for cars doing 30 mph. For an seventh scale RC car 1/2" off the ground it's a bit sketchy. What is not talked about is scaling the roads. This is a 1/7 scale car and scaling up, that would put the splitter just 3.5" off the ground on a full size car. A full size car with 3.5" of clearance is ridiculously low. This also means is that 1/4" dip is sucks up 1/2 that clearance on the scale car and would scale to 1.75" full size, which is a pretty big dip.
This has me thinking that my suspension is too stiff and the car is too low for the road I'm running on. All that good setup I've done has to get redone but higher and softer.
However, there is still one problem which is I'm confined to about 500' because of visibility and comfort. There are cars parked on both sides of the road, people riding bikes, etc.. Let's say it's a target rich environment.
The last piece to this road is the brakes. For some reason when I reverse it just goes ballistic reverse and it spins like a top. My current strategy is to let the car coast after the run (taking more space), then gently give a little brake until it's under control. I'm sure there is a setting some place that I don't yet understand or perhaps know about.
All that and yeah, I need a better road.
Hub Slop
After I got home I cleaned up the car and decided to do a bit of wrenching. I will start with I have no idea if this is legit or not, but it seems to make sense.
When I picked up the Limitless the suspension was super loose and everything was whacked.
The pillow balls adjustment was really loose. I have no idea why they are called pillow balls. Like balls I get but, pillow, I dunno?
The rear lower control arms are sloppy and there is some bizarre axial hub slop going on.
What's happening with the rear control arms is shoulder of the screw is too long for the width of the control arm. Unfortunately, the screw is not threaded far enough down to stake up the slack. So I can get a metric tap and add some thread to the screw, except I live in the USA and a metric tap, if you can find it, is very expensive. Or I can stick some washers on the ends to take up the slack. The washer solution won.
I had adjusted the pillow ball slack earlier when I set up the suspension. Done.
However, the axle/hub slop is a bit more complex. What's causing this slack is the axle goes through the hub (with bearings) and the length of the Axle CV is much larger than the width of the bearings.
This is a bad design has issues.
The first is the CV can move in and out of the bearings and that allow the wheels to move side to side on the car. Back to scaling, it's like have a very loose wheel and no bueno.
The next problem is a bit more complex, which is the bearing aren't really being used. This design can allow the CV can spin inside the inner bearing race and it becomes a sleeve bearing with no lubrication.
It would be better to have something, like a spring or cupped washer between the hub and bearing. It will connect the hub to the inner race and help the bearing spin correctly. . . .
Finding the exact spring washer it hard enough and we can't adjust tension anyway. Maybe some one will redesign the hubs, but that will be a while and we don't have time for that.
For now, I can only fix some of the side to side slop with a simple flat shim or two. It may not help the bearing spin but it will keep the wheels a bit more on track.
A bit of research lead me to video by East Tactics. TY!
The first thing is removing the hubs. It's pretty simple on paper, but since thread lock sales guy is really good, you'll need to loosen it up with a little love from the butane torch. Then it comes right out. OK, I use some thread lock for reassembly.
The shims I used the Kyosho .2mm washers (.05" for the 'Mericans). Some wheels took one and others took two, so I would recommend getting 2 packages, I need more.
The other thing I want to try is skateboard speed rings. This is exactly what they are meant to do and the diameters are good. What I don't know is the thickness and they look a bit stout.
https://www.amazon.com/gp/product/B002R6ZNQ6/ref=ox_sc_act_title_2?smid=A3CDEUCT9UACPY&psc=1
So I duplicated what he did. Here is before
And after
I will redo the suspension setup and give it a test drive soon.
I ran it again today and got to 61 mph! Now I only need to double that. This isn't that much faster but I learned few things from it.
- Stock gearing
- 27T/34T center
- 13T/43T F&R diff
- 100% ESC power limit - Linked to CH3
- THSPD on radio - Off
- Result 61 MPH in 500 foot run
The other change was removing the Throttle Delay from the RadioLink. It's a nice even gentle throttle curve and controls wheel spin but, it's a limiting factor.
With those two things I was able to get to 100% output on a few occasions.
Sketchy Road
The road I'm on is good for cars doing 30 mph. For an seventh scale RC car 1/2" off the ground it's a bit sketchy. What is not talked about is scaling the roads. This is a 1/7 scale car and scaling up, that would put the splitter just 3.5" off the ground on a full size car. A full size car with 3.5" of clearance is ridiculously low. This also means is that 1/4" dip is sucks up 1/2 that clearance on the scale car and would scale to 1.75" full size, which is a pretty big dip.
This has me thinking that my suspension is too stiff and the car is too low for the road I'm running on. All that good setup I've done has to get redone but higher and softer.
However, there is still one problem which is I'm confined to about 500' because of visibility and comfort. There are cars parked on both sides of the road, people riding bikes, etc.. Let's say it's a target rich environment.
The last piece to this road is the brakes. For some reason when I reverse it just goes ballistic reverse and it spins like a top. My current strategy is to let the car coast after the run (taking more space), then gently give a little brake until it's under control. I'm sure there is a setting some place that I don't yet understand or perhaps know about.
All that and yeah, I need a better road.
Hub Slop
After I got home I cleaned up the car and decided to do a bit of wrenching. I will start with I have no idea if this is legit or not, but it seems to make sense.
When I picked up the Limitless the suspension was super loose and everything was whacked.
The pillow balls adjustment was really loose. I have no idea why they are called pillow balls. Like balls I get but, pillow, I dunno?
The rear lower control arms are sloppy and there is some bizarre axial hub slop going on.What's happening with the rear control arms is shoulder of the screw is too long for the width of the control arm. Unfortunately, the screw is not threaded far enough down to stake up the slack. So I can get a metric tap and add some thread to the screw, except I live in the USA and a metric tap, if you can find it, is very expensive. Or I can stick some washers on the ends to take up the slack. The washer solution won.
I had adjusted the pillow ball slack earlier when I set up the suspension. Done.
However, the axle/hub slop is a bit more complex. What's causing this slack is the axle goes through the hub (with bearings) and the length of the Axle CV is much larger than the width of the bearings.
This is a bad design has issues.
The first is the CV can move in and out of the bearings and that allow the wheels to move side to side on the car. Back to scaling, it's like have a very loose wheel and no bueno.
The next problem is a bit more complex, which is the bearing aren't really being used. This design can allow the CV can spin inside the inner bearing race and it becomes a sleeve bearing with no lubrication.
It would be better to have something, like a spring or cupped washer between the hub and bearing. It will connect the hub to the inner race and help the bearing spin correctly. . . .
Finding the exact spring washer it hard enough and we can't adjust tension anyway. Maybe some one will redesign the hubs, but that will be a while and we don't have time for that.
For now, I can only fix some of the side to side slop with a simple flat shim or two. It may not help the bearing spin but it will keep the wheels a bit more on track.
A bit of research lead me to video by East Tactics. TY!
The first thing is removing the hubs. It's pretty simple on paper, but since thread lock sales guy is really good, you'll need to loosen it up with a little love from the butane torch. Then it comes right out. OK, I use some thread lock for reassembly.
The shims I used the Kyosho .2mm washers (.05" for the 'Mericans). Some wheels took one and others took two, so I would recommend getting 2 packages, I need more.
The other thing I want to try is skateboard speed rings. This is exactly what they are meant to do and the diameters are good. What I don't know is the thickness and they look a bit stout.
https://www.amazon.com/gp/product/B002R6ZNQ6/ref=ox_sc_act_title_2?smid=A3CDEUCT9UACPY&psc=1
So I duplicated what he did. Here is before
And after
I will redo the suspension setup and give it a test drive soon.
You need to use the droop screws to lower the front . Good on adding the wahers for the hubs. I did the same after a lot of reading and watching videos. I don't know if I would soften up the shocks. Last thing you want is hitting a bump and having the car spring back up and catch air under it.New PB, Sketchy Road and Sort of Fixing Hub Slop
I ran it again today and got to 61 mph! Now I only need to double that. This isn't that much faster but I learned few things from it.
Changing the ESC Max Power Adjustment controlled by my CH3 knob was brilliant. From the radio, I'm able to dial it down when I go to/from a run or just don't have the room for a full run. Or I can dial it up if I want have some fun and burn some tires.
- Stock gearing
- 27T/34T center
- 13T/43T F&R diff
- 100% ESC power limit - Linked to CH3
- THSPD on radio - Off
- Result 61 MPH in 500 foot run
The other change was removing the Throttle Delay from the RadioLink. It's a nice even gentle throttle curve and controls wheel spin but, it's a limiting factor.
With those two things I was able to get to 100% output on a few occasions.
View attachment 205924
Sketchy Road
The road I'm on is good for cars doing 30 mph. For an seventh scale RC car 1/2" off the ground it's a bit sketchy. What is not talked about is scaling the roads. This is a 1/7 scale car and scaling up, that would put the splitter just 3.5" off the ground on a full size car. A full size car with 3.5" of clearance is ridiculously low. This also means is that 1/4" dip is sucks up 1/2 that clearance on the scale car and would scale to 1.75" full size, which is a pretty big dip.
This has me thinking that my suspension is too stiff and the car is too low for the road I'm running on. All that good setup I've done has to get redone but higher and softer.
However, there is still one problem which is I'm confined to about 500' because of visibility and comfort. There are cars parked on both sides of the road, people riding bikes, etc.. Let's say it's a target rich environment.
The last piece to this road is the brakes. For some reason when I reverse it just goes ballistic reverse and it spins like a top. My current strategy is to let the car coast after the run (taking more space), then gently give a little brake until it's under control. I'm sure there is a setting some place that I don't yet understand or perhaps know about.
All that and yeah, I need a better road.
Hub Slop
After I got home I cleaned up the car and decided to do a bit of wrenching. I will start with I have no idea if this is legit or not, but it seems to make sense.
When I picked up the Limitless the suspension was super loose and everything was whacked.
The pillow balls adjustment was really loose. I have no idea why they are called pillow balls. Like balls I get but, pillow, I dunno?
What's happening with the rear control arms is shoulder of the screw is too long for the width of the control arm. Unfortunately, the screw is not threaded far enough down to stake up the slack. So I can get a metric tap and add some thread to the screw, except I live in the USA and a metric tap, if you can find it, is very expensive. Or I can stick some washers on the ends to take up the slack. The washer solution won.
View attachment 205940
I had adjusted the pillow ball slack earlier when I set up the suspension. Done.
However, the axle/hub slop is a bit more complex. What's causing this slack is the axle goes through the hub (with bearings) and the length of the Axle CV is much larger than the width of the bearings.
View attachment 205948
This is a bad design has issues.
The first is the CV can move in and out of the bearings and that allow the wheels to move side to side on the car. Back to scaling, it's like have a very loose wheel and no bueno.
The next problem is a bit more complex, which is the bearing aren't really being used. This design can allow the CV can spin inside the inner bearing race and it becomes a sleeve bearing with no lubrication.
It would be better to have something, like a spring or cupped washer between the hub and bearing. It will connect the hub to the inner race and help the bearing spin correctly. . . .
View attachment 205950
Finding the exact spring washer it hard enough and we can't adjust tension anyway. Maybe some one will redesign the hubs, but that will be a while and we don't have time for that.
For now, I can only fix some of the side to side slop with a simple flat shim or two. It may not help the bearing spin but it will keep the wheels a bit more on track.
View attachment 205954
A bit of research lead me to video by East Tactics. TY!
The first thing is removing the hubs. It's pretty simple on paper, but since thread lock sales guy is really good, you'll need to loosen it up with a little love from the butane torch. Then it comes right out. OK, I use some thread lock for reassembly.
The shims I used the Kyosho .2mm washers (.05" for the 'Mericans). Some wheels took one and others took two, so I would recommend getting 2 packages, I need more.
View attachment 205945
The other thing I want to try is skateboard speed rings. This is exactly what they are meant to do and the diameters are good. What I don't know is the thickness and they look a bit stout.
https://www.amazon.com/gp/product/B002R6ZNQ6/ref=ox_sc_act_title_2?smid=A3CDEUCT9UACPY&psc=1
So I duplicated what he did. Here is before
And after
I will redo the suspension setup and give it a test drive soon.
View attachment 205947
View attachment 205953
- Thread starter
- #25
My thought is the ride height and spring rates are correlated. In this case it's not really dragging the bottom a lot. There were a few little scrapes but wasn't consistent. What I'm seeing is the car skipping on the bumps.
Which is why I'm thinking the springs are too stiff. So if I soften the suspsension, I will need to raise it up a bit?
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That is a tuff situation.
To go really fast you need stiff springs. Which also means you need a really smooth road.
To go really fast you need stiff springs. Which also means you need a really smooth road.
I think I saw Raz Shifren use turnbuckles (or something similar) as replacements for shocks on one or more of his speed run cars.
- Thread starter
- #28
LOL that is a super bad idea for anything that is not like glass. It's an infinite spring rate makes the tires your suspension travel. Which means every bump is transferred directly to your chassis and it upsets the car ... and the driver by crashing.
- Thread starter
- #29
New PB, Still too slow, Excessive Load and what is a Time v Time graph?
Cutting to the chase with the questions, with more info below.
I finally got some time where I could get out an run the Limitless. I found a great spot about 20 mins from home. During the time I was there I saw 3 cars and one actually drove down the street.
It's smooth, flat, wide with no cars and about 1600 ft long.
It's in a business park and there is no parking allowed on the streets, so it's wide open. I took a chance and parked in a parking lot. It seemed to work out fine.
However, I ran into some problems with the car and I'm not sure what I'm looking at? I can use some help decoding it.
New PB
Before I left I cleared out my data log, checked everything to make sure it's tight, charged the batteries and changed my pinion to a 32T (from 27T). This resulted in a PB of 76 MPH. It ran straight and I actually got the doppler shift,.
But I was expecting more speed.
According to my calculations (https://www.radiocontrolinfo.com) I should be over 100 MPH. This is calculated using 6S to account for friction and areo drag, this is probably the worst case. Best case is 136 MPH. Looking at other setups and the calculator, I was kinda of expecting at least triple digits.
There area few things in question.
Radio Setup
I have my setup where CH3 controls my Max Power Adjustment. It's convenient if I just need to test something and not worry about putting it through the wall or a child. Just dial it back and it's a super slow and controllable car.
However, my Radio Link only shows 75% throttle when it's dialed all the way up. It goes 100% reverse though.
The next question is the
ESC Audible Codes
On a few runs it came back and was beeping - short, long long. Which, according to Castle is Excessive Load.
When I look at the data log I don't see any glitches or spikes that would cause this. Although, it's possible it happens in between the samples (5/sec), I just don't see it. My data log and setup are in the attached ZIP file. There are two setup files, the latter one 20220423.dat is the one I used today.
Looking at the log file the max current is only 151 Amps, which seems more than reasonable. It only hit full power once at 99.6%.
I have no idea how to read the Throttle In because both axis are time?
TIA, any input is welcome!
Cutting to the chase with the questions, with more info below.
- Why does my Radio Link only show 75% max throttle on Channel 3 (set up for y Max Power Adjustment)?
- Why do I get Excessive Load warnings, when the current is only 151A?
- How do I read the Throttle In graph, both axis are time?
I finally got some time where I could get out an run the Limitless. I found a great spot about 20 mins from home. During the time I was there I saw 3 cars and one actually drove down the street.
It's smooth, flat, wide with no cars and about 1600 ft long.
It's in a business park and there is no parking allowed on the streets, so it's wide open. I took a chance and parked in a parking lot. It seemed to work out fine.
However, I ran into some problems with the car and I'm not sure what I'm looking at? I can use some help decoding it.
New PB
Before I left I cleared out my data log, checked everything to make sure it's tight, charged the batteries and changed my pinion to a 32T (from 27T). This resulted in a PB of 76 MPH. It ran straight and I actually got the doppler shift,
.But I was expecting more speed.
According to my calculations (https://www.radiocontrolinfo.com) I should be over 100 MPH. This is calculated using 6S to account for friction and areo drag, this is probably the worst case. Best case is 136 MPH. Looking at other setups and the calculator, I was kinda of expecting at least triple digits.
There area few things in question.
Radio Setup
I have my setup where CH3 controls my Max Power Adjustment. It's convenient if I just need to test something and not worry about putting it through the wall or a child. Just dial it back and it's a super slow and controllable car.
However, my Radio Link only shows 75% throttle when it's dialed all the way up. It goes 100% reverse though.
The next question is the
ESC Audible Codes
On a few runs it came back and was beeping - short, long long. Which, according to Castle is Excessive Load.
When I look at the data log I don't see any glitches or spikes that would cause this. Although, it's possible it happens in between the samples (5/sec), I just don't see it. My data log and setup are in the attached ZIP file. There are two setup files, the latter one 20220423.dat is the one I used today.
Looking at the log file the max current is only 151 Amps, which seems more than reasonable. It only hit full power once at 99.6%.
I have no idea how to read the Throttle In because both axis are time?
TIA, any input is welcome!
Last edited:
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Probably will be good to do some process of elimination. (Make sure it runs normal and no errors)
Do the same run and setup minus the channel 3 / aux wire setup and see what happens.
Do the same run and setup minus the channel 3 / aux wire setup and see what happens.
Last edited:
- Thread starter
- #31
Another Day, a Crash and New PB
Cutting to the chase
I hit 111 Mph on my 5th pass today!
The Tune up
Over the last few weeks I've been tuning the electronics a bit and manage to make some headway. One of the issues is, I wasn't getting 100% throttle. I had the "Max Power Adjustment" on the CH3 dial, so I removed it. That was a convenience where I could dial back the power to get to/from the run and not worry about spinning it into oblivion by accident.
I also recalibrated the ESC, which was a little weird. Originally I had calibrated it (or so I thought) then plugged it in and found that it had just a touch of forward throttle at 0% trim. So I trimmed it back and saved it for another day. I tried to recalibrate it later and it wouldn't work. Searching for some answers, I found a post or YT or something that said the motor had to be in the "Forward" direction on the ESC. So I swapped that back, reset my trim to 0% and recalibrated.
That's when I saw my radio throttle was reversed, even though the setting said it was normal? Which explains why I couldn't recalibrate. I dunno what it was, so I reversed the throttle on the radio and it did something and I'm guessing it right? Trim is 0%, forwards and reverse work correctly.
When I was out running I also figured out my "Excessive Load" problem. It's only when I punch it from a stand still. If anyone know why this is an issue please let me know. Maybe it's just a quirk of big gears or something else, but I can correct it by not doing burnouts and donuts.
On the Road
This morning, with batteries charged and inspired by Earl joining the 200 MPH club, I got over to my new spot. It's 1600 ft of flat wide straight road. There area few hazards like California Road Turtles and some utility covers, but there is almost no traffic and no parking in the streets. Which is great when you crash because no one complains if you put your RC into a curb or a bush.
... which is sort of what happened.
The fist pass was 80 MPH, which is good and it sounded healthy too. Next run was 86 MPH and figured I needed to stay in the throttle a bit more. i.e. don't be such a chicken. - No offense to any chickens reading this, of course.
With my courage up I started the next pass, and the car spun around got 5' in the air and slammed into the curb. Oops. I checked the GPS and it was maxed 74 MPH. Bummer. There wasn't much damage. The splitter got buggered up and the driver's front spoiled came off.
View attachment 217583
Also the driver's rear lower wing mount pulled through the plastic but was field repairable as "good enough". The rest is mostly cosmetic but I will tear it down and check it out.
As a result of the crash the car picked up a little bit of extra material. I'm not sure what that is, maybe a piece of a turtle, some paint from the line...? I search the area and couldn't find anything that matched, except for a 1/2" wide piece of plastic really stuck to the road. I have no idea what it is? Maybe I collect that along the way and it caused the spin and flip, or mostly likely I'm not a good driver.
This is what it looked like under the car. I will dig this thing out and update the thread if it's anything interesting.
Looking at my data log I got 100% throttle. I think I just need to stay into it longer.
This is the 111 MPH run with RPM Throttle (which I still don't understand ms/ms?) and power out.
Also my ESC setup
Cutting to the chase
I hit 111 Mph on my 5th pass today!
The Tune up
Over the last few weeks I've been tuning the electronics a bit and manage to make some headway. One of the issues is, I wasn't getting 100% throttle. I had the "Max Power Adjustment" on the CH3 dial, so I removed it. That was a convenience where I could dial back the power to get to/from the run and not worry about spinning it into oblivion by accident.
I also recalibrated the ESC, which was a little weird. Originally I had calibrated it (or so I thought) then plugged it in and found that it had just a touch of forward throttle at 0% trim. So I trimmed it back and saved it for another day. I tried to recalibrate it later and it wouldn't work. Searching for some answers, I found a post or YT or something that said the motor had to be in the "Forward" direction on the ESC. So I swapped that back, reset my trim to 0% and recalibrated.
That's when I saw my radio throttle was reversed, even though the setting said it was normal? Which explains why I couldn't recalibrate. I dunno what it was, so I reversed the throttle on the radio and it did something and I'm guessing it right? Trim is 0%, forwards and reverse work correctly.
When I was out running I also figured out my "Excessive Load" problem. It's only when I punch it from a stand still. If anyone know why this is an issue please let me know. Maybe it's just a quirk of big gears or something else, but I can correct it by not doing burnouts and donuts.
On the Road
This morning, with batteries charged and inspired by Earl joining the 200 MPH club, I got over to my new spot. It's 1600 ft of flat wide straight road. There area few hazards like California Road Turtles and some utility covers, but there is almost no traffic and no parking in the streets. Which is great when you crash because no one complains if you put your RC into a curb or a bush.
... which is sort of what happened.
The fist pass was 80 MPH, which is good and it sounded healthy too. Next run was 86 MPH and figured I needed to stay in the throttle a bit more. i.e. don't be such a chicken.
- No offense to any chickens reading this, of course.With my courage up I started the next pass, and the car spun around got 5' in the air and slammed into the curb. Oops. I checked the GPS and it was maxed 74 MPH. Bummer. There wasn't much damage. The splitter got buggered up and the driver's front spoiled came off.
View attachment 217583
Also the driver's rear lower wing mount pulled through the plastic but was field repairable as "good enough". The rest is mostly cosmetic but I will tear it down and check it out.
As a result of the crash the car picked up a little bit of extra material. I'm not sure what that is, maybe a piece of a turtle, some paint from the line...? I search the area and couldn't find anything that matched, except for a 1/2" wide piece of plastic really stuck to the road. I have no idea what it is? Maybe I collect that along the way and it caused the spin and flip, or mostly likely I'm not a good driver.
This is what it looked like under the car. I will dig this thing out and update the thread if it's anything interesting.
Looking at my data log I got 100% throttle. I think I just need to stay into it longer.
This is the 111 MPH run with RPM Throttle (which I still don't understand ms/ms?) and power out.
Also my ESC setup
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Ideally you want to find your best run in the logs to analyze and then click and drag your mouse over that run to zoom into it.
After zooming into your logs I can see that they are rather short like you were saying "Need to stay into it longer"
The biggest thing is throttle input.
If you focus on that black line you can see the last 30% you ramped up the throttle suddenly. Work on keep it smooth and linear.
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- #33
Thank you for looking at the log and the feedback. That makes complete sense and concur with what I recall from driving. I think what's happening is I'm better at driving the car when it's going way from me, so I hammer down right when it passes me.
I feel like that will be better with more "stick time" and confidence. Having a 15 lb projectile coming at you at 100 mph is .... sketchy at best. It has about the same energy as thirteen .45 caliber rounds coming at you at the same time.
Maybe more runs at lower speeds might be a good way to build up it.
I feel like that will be better with more "stick time" and confidence. Having a 15 lb projectile coming at you at 100 mph is .... sketchy at best. It has about the same energy as thirteen .45 caliber rounds coming at you at the same time.
Maybe more runs at lower speeds might be a good way to build up it.
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Certainly is something to be said about experience / stick time. Tuning the car to drive straight helps a ton.
Also I highly recommend running the new GRP tires while you are cutting your teeth. I am using the GRP GTJ XM3 and really like the grip. Now with the crash roughing up the wheel/tire it may be a good time?
Another side note is safety while running as you mentioned there is some serious danger. Several ways to do it. (stand on 1:1 car, ladder, etc...)
I stand in the street and when the car is approaching I back up and have my 1:1 car as a shield for me. I like standing on the roof of the car a lot for the better visibility but I am getting too old to jump down without hurting myself
Since I am going to have another week of high winds (20+ mph) maybe I'll build myself a custom ladder to get onto the roof of my SUV
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- Thread starter
- #35
Certainly is something to be said about experience / stick time. Tuning the car to drive straight helps a ton.
Also I highly recommend running the new GRP tires while you are cutting your teeth. I am using the GRP GTJ XM3 and really like the grip. Now with the crash roughing up the wheel/tire it may be a good time?
Another side note is safety while running as you mentioned there is some serious danger. Several ways to do it. (stand on 1:1 car, ladder, etc...)
I stand in the street and when the car is approaching I back up and have my 1:1 car as a shield for me. I like standing on the roof of the car a lot for the better visibility but I am getting too old to jump down without hurting myself
Since I am going to have another week of high winds (20+ mph) maybe I'll build myself a custom ladder to get onto the roof of my SUV
Crash aside, I figured it was time for a tire upgrade because other's have said that the stock tires are good to about 100 mph a few times. So I ordered the GRP GTJ TO3 XB1. The GRP website is not very descriptive and it's a bit confusing with the X/J & XM/XB compound. My thought is that it's a bit of trial and error with my car setup and the conditions. Hopefully they work out.
There are some raised grass areas in the area, about 5 feet up. I figure the grass will make the fall much more comfortable when the car takes me out.
In all seriousness I'm trying to keep a low profile because it's all private property in a business park full of tech companies with security that has nothing to do on a Sat morning. My approaching view looks like this, no sign though, and the departure is the reverse and I'm standing in the middle of a court intersection. The ladder or parking my car on the corner might be a good option.
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Crash aside, I figured it was time for a tire upgrade because other's have said that the stock tires are good to about 100 mph a few times. So I ordered the GRP GTJ TO3 XB1. The GRP website is not very descriptive and it's a bit confusing with the X/J & XM/XB compound. My thought is that it's a bit of trial and error with my car setup and the conditions. Hopefully they work out.
There are some raised grass areas in the area, about 5 feet up. I figure the grass will make the fall much more comfortable when the car takes me out.
In all seriousness I'm trying to keep a low profile because it's all private property in a business park full of tech companies with security that has nothing to do on a Sat morning. My approaching view looks like this, no sign though, and the departure is the reverse and I'm standing in the middle of a court intersection. The ladder or parking my car on the corner might be a good option.
View attachment 218161
View attachment 218162
Looks pretty good, maybe stand behind a tree for protection....
The only thing that stands out is the man hole cover.
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- #37
New Runs, Busted Battery and Some Video
Went out this morning with a friend and did some runs. His first run got 91 mph, but there should be more. We check the battery and it had a bad cell. So we put my CNHL 9500 in there and let her rip.
This time around he lost signal and the car rolled around the corner onto the side street. It was actually kinda of funny because it's last thing we expected. That run was only 81 MPH, not great at all.
We took the car back and pulled the battery and it had some very strange cell readings. Like how the heck do you get nearly 5V on a cell without it puffing?
His setup is a 4S with a 2020 and a giant pie pan pinion and a tiny spool. The only thing I can thing of is it was over current/excessive voltage droop (AKA ripple) and killed the battery. However, if my math is right that battery, at full charge, should be able to supply 855 Amps. We will see what the data log says. There is another post on that if you have any ideas.
https://www.arrmaforum.com/threads/battery-cell-readings.52261/
That battery got to sit on the shady asphalt for a while for a little time out until it behaved. At the end of the day the readings are still the same. So it's going in the trash.
At this point, I'm down to 1 battery and 4S power. Which is OK because I really need some time just driving the thing in a straight line. Same setup as before I got 75 mph with all the aero off. Oh the aero came off after I mounted a road turtle. Apparently that's bad for the car.
Went out this morning with a friend and did some runs. His first run got 91 mph, but there should be more. We check the battery and it had a bad cell. So we put my CNHL 9500 in there and let her rip.
This time around he lost signal and the car rolled around the corner onto the side street. It was actually kinda of funny because it's last thing we expected. That run was only 81 MPH, not great at all.
We took the car back and pulled the battery and it had some very strange cell readings. Like how the heck do you get nearly 5V on a cell without it puffing?
His setup is a 4S with a 2020 and a giant pie pan pinion and a tiny spool. The only thing I can thing of is it was over current/excessive voltage droop (AKA ripple) and killed the battery. However, if my math is right that battery, at full charge, should be able to supply 855 Amps. We will see what the data log says. There is another post on that if you have any ideas.
https://www.arrmaforum.com/threads/battery-cell-readings.52261/
That battery got to sit on the shady asphalt for a while for a little time out until it behaved. At the end of the day the readings are still the same. So it's going in the trash.
At this point, I'm down to 1 battery and 4S power. Which is OK because I really need some time just driving the thing in a straight line. Same setup as before I got 75 mph with all the aero off. Oh the aero came off after I mounted a road turtle. Apparently that's bad for the car.
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- #38
New batteries
After the debacle of whatever that was, it's time to do some updates.
CNHL was gracious enough to take care of me which is way above and beyond anything I can ever ask for. I still don't know what caused the failure, but I'm down to 1 4S battery, which seems to limit my speed a bit. At least for the current setup. Unfortunately, CNHL didn't have any of the same battery or anything with 8 Ga wires and I need to find another solution with matching batteries.
There is lots of advise out there about batteries. Some of it's good and some of it is snake oil. It turns out you can do the math, but it's not exactly correct, because the C rating is somewhat arbitrary and mostly made up by the manufacturer.
There is a post in RC groups that is often referred to that is sort of helpful.
https://www.rcgroups.com/forums/showthread.php?1767093-Battery-Load-Test-Comparisons
In this post they actually test the batteries and post the results. A few batteries exceed some of the ratings but most of them don't get close. Then again this is a two dimensional representation of a 3 dimensional problem. Meaning that they use a steady current draw and you probably don't drive like that but it's well thought out testing and good data.
Anyway I tried to decode the magical tables but they doesn't really call out the make/model of the battery well enough to actually buy, it in most cases. What I did figure out is that it's all 6S and you can probably find something or close to it by looking at the mAH rating and weight.
Also it's hard to find good batteries for some reason. It's like they are made from Unicorn Poop or something. Which is why I couldn't get the matching CNHL battery. I guess the solution is more unicorns.
Looking at the graphs I'm consistently seeing the SMC 6200 40C at or near the top of every rating.
And the hunt begins. . . At this point I'm taking a bit of a swag too.
What I found the only 6S - 6200 Mah is the True Spec Extreme Graphene V2 Flight 22.2V-6200mAh-40C. I'm not sure if the SMC website shows batteries not in stock so there might be others. Then moving over to 4S in the same family and taking the largest capacity I could find, I found the True Spec Extreme Graphene V2 Flight 18.5V-7700mAh-40C-BVM. And they were on sale for $50 too. At the 2 for 1 price of the CHNL I can at least try them out. In reality I'm not getting to 150+ MPH and I'm doubting that the battery is that critical yet.
The arrived and I found out they are a weird shape. They don't lay flat in the Limitless battery tray, they are too wide. Which means I need to stand them up.
This isn't ideal but it's OK. I have some ABS remnant from Tap Plastics that I can cut up and use a spacers on the side and one on the bottom.
I will need to change the connector and shorten up the leads a bit too.
If you feel the pack, it feels like there are 8 smaller cells in there and its in a 2P4S configuration. Which would ideally have the ability to deliver more current. I guess we will find out when I get the rest of it back together.
After the debacle of whatever that was, it's time to do some updates.
CNHL was gracious enough to take care of me which is way above and beyond anything I can ever ask for. I still don't know what caused the failure, but I'm down to 1 4S battery, which seems to limit my speed a bit. At least for the current setup. Unfortunately, CNHL didn't have any of the same battery or anything with 8 Ga wires and I need to find another solution with matching batteries.
There is lots of advise out there about batteries. Some of it's good and some of it is snake oil. It turns out you can do the math, but it's not exactly correct, because the C rating is somewhat arbitrary and mostly made up by the manufacturer.
There is a post in RC groups that is often referred to that is sort of helpful.
https://www.rcgroups.com/forums/showthread.php?1767093-Battery-Load-Test-Comparisons
In this post they actually test the batteries and post the results. A few batteries exceed some of the ratings but most of them don't get close. Then again this is a two dimensional representation of a 3 dimensional problem. Meaning that they use a steady current draw and you probably don't drive like that but it's well thought out testing and good data.
Anyway I tried to decode the magical tables but they doesn't really call out the make/model of the battery well enough to actually buy, it in most cases. What I did figure out is that it's all 6S and you can probably find something or close to it by looking at the mAH rating and weight.
Also it's hard to find good batteries for some reason. It's like they are made from Unicorn Poop or something. Which is why I couldn't get the matching CNHL battery. I guess the solution is more unicorns.
Looking at the graphs I'm consistently seeing the SMC 6200 40C at or near the top of every rating.
And the hunt begins. . . At this point I'm taking a bit of a swag too.
What I found the only 6S - 6200 Mah is the True Spec Extreme Graphene V2 Flight 22.2V-6200mAh-40C. I'm not sure if the SMC website shows batteries not in stock so there might be others. Then moving over to 4S in the same family and taking the largest capacity I could find, I found the True Spec Extreme Graphene V2 Flight 18.5V-7700mAh-40C-BVM. And they were on sale for $50 too.
At the 2 for 1 price of the CHNL I can at least try them out. In reality I'm not getting to 150+ MPH and I'm doubting that the battery is that critical yet.The arrived and I found out they are a weird shape. They don't lay flat in the Limitless battery tray, they are too wide. Which means I need to stand them up.
This isn't ideal but it's OK. I have some ABS remnant from Tap Plastics that I can cut up and use a spacers on the side and one on the bottom.
I will need to change the connector and shorten up the leads a bit too.
If you feel the pack, it feels like there are 8 smaller cells in there and its in a 2P4S configuration. Which would ideally have the ability to deliver more current. I guess we will find out when I get the rest of it back together.
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Hey Jerold, have you tried to reverse the throttle on the radiolink and recalibrating the forwards, neutral, and reverse yet?
I had issues with that on a few vehicles. What I did was, I put the esc (xlx2 programing) to regular not reversed, and then reversed the radio’s setting (throttle reversed). then did the for,neu,rev, calibration over. and had no issues with forwards power vs reverses power feeling wrong.
Radio links I’ve been reading have an issue in this area
I had issues with that on a few vehicles. What I did was, I put the esc (xlx2 programing) to regular not reversed, and then reversed the radio’s setting (throttle reversed). then did the for,neu,rev, calibration over. and had no issues with forwards power vs reverses power feeling wrong.
Radio links I’ve been reading have an issue in this area
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- #40
Hi Alan,
Yes, that what I did in the Tune Up on post #31. I stumbled into it when I was trying to re-calibrate my ESC. I undid the Motor Reverse, the calibrated and reversed the radio. I'm getting full throttle on my radio and in the logs.
