Didn't Hyena say his could be changed by altering a file on the card (or in it's internal memory, I forget which)? But that it overwrote taht file and reset to default each time it was power cycled?
Dogmans racing bike
- Thread starter dogman dan
- Start date
GCinDC
100 MW
Yeah, but change won't last. I've got some vids w proper date but it resets at startup? Very tricky to operate, aim etc, but light as air. Easy to clip to anything...amberwolf said:
Love to see more vids!
The Mighty Volt
1 MW
Just my $0.02..........nothing beats having the weight in the middle.
Apart from that you are doing OK because your weight is not just lumped onto the back holus bolus.
Apart from that you are doing OK because your weight is not just lumped onto the back holus bolus.
That was certainly true on CrazyBike2--when I moved the 45lbs of SLA to the center triangle from the rear just in front of and below the axles, even though it was slightly higher in the center it was still much easier to maneuver, tilt, etc, and then recover afterwards.The Mighty Volt said:
dogman dan
1 PW
Experimenting with coroplast fairings. Obviously much room for improvement. My gut feeling is that this is just too large, but it's about as small as I could get it to be and still cover the brake levers. Mabye just as good to have one half the size, and count on the hole it punches in the wind being bigger than it is. The basic aim is to divert some wind from the lower chest and groin area. The upper chest will be in the wind unless I lose 20 pounds for the race. 
Not too likely but I'd fold into a better tuck without the extra tire.
It will take lots of testing to know what does what to the top speed, and all of it will be muddied by other variables, dammit. hours and hours of entertainment though.
This one has a notch for the wheel, but I may just make it flatter on the bottom, and raked on the top, to put some wing traction on the front tire. Then it wouldn't need the notch.
The bike without batteries now weighs 53 pounds. So I could carry 15 pounds of lipo in a race with a 70 pound weight limit. About 15 ah of 20s.
Not too likely but I'd fold into a better tuck without the extra tire. It will take lots of testing to know what does what to the top speed, and all of it will be muddied by other variables, dammit. hours and hours of entertainment though.
This one has a notch for the wheel, but I may just make it flatter on the bottom, and raked on the top, to put some wing traction on the front tire. Then it wouldn't need the notch.
The bike without batteries now weighs 53 pounds. So I could carry 15 pounds of lipo in a race with a 70 pound weight limit. About 15 ah of 20s.
The large piece up front will slow you down your better off without it. Electronics are not my strong suit but I know my share about aerodynamics. What regulations are their? Please ask me anything you have a question about I can definitely help with this.
I would venture to say that putting a tailpiece on that smooths the airflow coming off your back and stuff would make more difference than a front fairing. But having never experimented directly with it, I might be wrong. I've seen all sorts of vehicle shapes for air, water, land, with all sorts of front ends, including some that couldn't really be all that aero, but a nearly universal constant is the tail smoothing out to the back.
maydaverave
10 kW
- Joined
- Jan 13, 2009
- Messages
- 542
Lycra would probably do more good than a fairing 8) :lol:
a tail smoothing effect would be what you want to create in a low pressure situation but it would be hard to do considering you'll have to be moving(sometimes in a tuck others sitting upright) so unless it was form fitting and had minimal air leaking into it, it would create the opposite effect and actual slow you down. Either way if you do decide to make a smooth tail you should put a small hole at the end of it to allow an escape for any air that does flow in.amberwolf said:
AussieJester
1 TW
maydaverave said:
thehehe... what you say DogMan you gunna Lycra it up for the 'Death Race' :lol:
Bikes looking good mate.. :wink:
KiM
dogman dan
1 PW
Yeah, funny how it looked right on the table, but put on the bike it looks like a huge windcatcher. It's cut down a lot now, but I still like the idea of directing at least a little bit of air off my chest. mabye just put a taller dashboard on the battery fairing?
No rules to speak of at the Spooky Tooth death race. Lots of fast gasoline bikes that will kick my butt. I just want to run with the medium fast ones, at 40 mph or so. Supposing I don't crash the corners with 40 mph that is.
No rules to speak of at the Spooky Tooth death race. Lots of fast gasoline bikes that will kick my butt. I just want to run with the medium fast ones, at 40 mph or so. Supposing I don't crash the corners with 40 mph that is.
dogman dan
1 PW
Here is what the fairing turned into, mounted and ridable. It seems to work, since if I get out of the tuck, I feel wind hit my shoulders. Maybe cut it down even more, and rebuild it to have softer corners once I have the size right.
Battery data too, from ride 2, but no video since I left the dang thing at work with my commuter when I got sick last week. From a 20s pack charged to 4.15v, I went out and rode 3 miles of racing type conditions. I rode to top speed for about 700', hitting about 36 mph. Then I'd brake to 25 mph, hit throttle for 10 seconds, brake down to 25 mph, repeating this 4-5 times. Then back up to 35 mph and another cycle of hard braking and hard throttle. Trying as best I could to simulate track conditions in Tucson.
After 3 miles, the blue lights were flashing on my lv beepers. Those go off about 3.75 v. Slowing down and riding less fast in a residential neighborhood for some cornering, I got another 3 miles before the red lights and beeps began when using the throttle. So at that point I was sagging to 3.5v.
So it looks to me like a 20s pack of 10 ah, would still only be good to go about 6 miles of racing before sagging to slower speeds. Not good, looks like 20 ah of 72v will be needed to do well in the Death race, That is 12 miles of racing in the final heat. So to bring charged batteries for just the heat race of 8 miles and the death race is going to mean 28 5 ah blocks of 5s lipo. $$$$$$
Affording enough for just the heat race may be all I can do, and have to sit out the death race itself. Hopefully, I will find that when I have enough lipo to run a 10 ah pack, voltage sag will happen slower. But for sure, braking hard and then slamming the throttle every 100' hammers a battery, even 30c lipo.
Thinking some more, the batteries did get quite warm on that run, usually a sign that you've cut your range quite a bit. Mabye if I go 10 ah, halfing the c rate on the cells, and add 3s to run 23s I could get though a race on 10 ah. When they got to 3.75v, I'd likely still have 6 miles left, and 80v or so of speed. Might squeeze out 15 miles out of 10 ah then. No way I can afford two sets of 72v 20 ah. Not enough time to do much recharging either. Recharging a practice set of 4 might be possible by the main event unless you have some kind of expensive fast chargers. But then there's no high amp plugs to use at the track.
Battery data too, from ride 2, but no video since I left the dang thing at work with my commuter when I got sick last week. From a 20s pack charged to 4.15v, I went out and rode 3 miles of racing type conditions. I rode to top speed for about 700', hitting about 36 mph. Then I'd brake to 25 mph, hit throttle for 10 seconds, brake down to 25 mph, repeating this 4-5 times. Then back up to 35 mph and another cycle of hard braking and hard throttle. Trying as best I could to simulate track conditions in Tucson.
After 3 miles, the blue lights were flashing on my lv beepers. Those go off about 3.75 v. Slowing down and riding less fast in a residential neighborhood for some cornering, I got another 3 miles before the red lights and beeps began when using the throttle. So at that point I was sagging to 3.5v.
So it looks to me like a 20s pack of 10 ah, would still only be good to go about 6 miles of racing before sagging to slower speeds. Not good, looks like 20 ah of 72v will be needed to do well in the Death race, That is 12 miles of racing in the final heat. So to bring charged batteries for just the heat race of 8 miles and the death race is going to mean 28 5 ah blocks of 5s lipo. $$$$$$
Affording enough for just the heat race may be all I can do, and have to sit out the death race itself. Hopefully, I will find that when I have enough lipo to run a 10 ah pack, voltage sag will happen slower. But for sure, braking hard and then slamming the throttle every 100' hammers a battery, even 30c lipo.Thinking some more, the batteries did get quite warm on that run, usually a sign that you've cut your range quite a bit. Mabye if I go 10 ah, halfing the c rate on the cells, and add 3s to run 23s I could get though a race on 10 ah. When they got to 3.75v, I'd likely still have 6 miles left, and 80v or so of speed. Might squeeze out 15 miles out of 10 ah then. No way I can afford two sets of 72v 20 ah. Not enough time to do much recharging either. Recharging a practice set of 4 might be possible by the main event unless you have some kind of expensive fast chargers. But then there's no high amp plugs to use at the track.
dogman dan
1 PW
A run on the practice track at the stadium parking lot. This lot is exactly the size to give me just about the same distance as the longest straights on the Tucson cart track.
Kinda dissapointing. Again running about 3 miles to the first beep of the lv buzzers. That used 3 ah. Hopefully with 4 more batteries I'll get 8 ah before sagging. I had the Ca on it, but didn't hook up the speedo. On the bike speedo, I never saw more speed than 38 mph, and most of the time, it was hard to get up to even 35 on the straights. Not exactly equaling fairracing 31's 45 mph on the same length. Cornering faster will help, but I was pussy cornering today, usually not over 23 mph. That cornering skill doesn't just pop out when you need it, after a few months with no cornering above 25. I was a bit spooked, since a huge rain the other night left the parking lot covered with little spots of dust where a puddle had been. I was definitely not sure if I was going to lay er down or not with a dusty road.
I was pulling about 35 amps most of the time, and seeing about 2600-2800 watts. So the power is there, it's just going to take more that I thought to get to 45 mph in 700'.
No video, I thought I had the cam running but it wasn't. I got a flakey one, that is for sure. I'll have to buy another and try again. Typical of chargers, so why not with cameras from china?
Kinda dissapointing. Again running about 3 miles to the first beep of the lv buzzers. That used 3 ah. Hopefully with 4 more batteries I'll get 8 ah before sagging. I had the Ca on it, but didn't hook up the speedo. On the bike speedo, I never saw more speed than 38 mph, and most of the time, it was hard to get up to even 35 on the straights. Not exactly equaling fairracing 31's 45 mph on the same length. Cornering faster will help, but I was pussy cornering today, usually not over 23 mph. That cornering skill doesn't just pop out when you need it, after a few months with no cornering above 25. I was a bit spooked, since a huge rain the other night left the parking lot covered with little spots of dust where a puddle had been. I was definitely not sure if I was going to lay er down or not with a dusty road.
I was pulling about 35 amps most of the time, and seeing about 2600-2800 watts. So the power is there, it's just going to take more that I thought to get to 45 mph in 700'.
No video, I thought I had the cam running but it wasn't. I got a flakey one, that is for sure. I'll have to buy another and try again. Typical of chargers, so why not with cameras from china?
torker
100 kW
Might check out this one Dogman. It got linked a few days ago on the other video thread.http://www.dealextreme.com/details.dx/sku.32022
It looks good for the money.. It may even be the same camera. I haven't seen the Turnigy.
It looks good for the money.. It may even be the same camera. I haven't seen the Turnigy.
dogman dan
1 PW
Looks same as the other mini cam at HK. I think I'll just add another one to the next box o batteries. Others like thiers, but I got a stinker. I think maybe one of the buttons isn't working properly, and it only works in voice mode, and then goes to off. But if I try again, I get a spare card and battery cheap.
Hopefully at the actual race, others bring real cameras.
Hopefully at the actual race, others bring real cameras.
Thud
1 MW
dogman,
How are you feeling with the practice bike & the lack of suspension? I am of the opinion that the weight penalty of a decent suspension would be a HUGE confidence builder on the race set up.
What are your thoughts in that regard?
Batteries-right now I am running 20-25c rated packs (the cheap ones) But I have allways run at least 15ah.(3p) I have yet to experiance voltage sag as you seem to be getting. I would think 3p would be a min requirment. As of today I have 25AH at 66.6v (i can't justify the added voltage on an rc set up.......I have run the big turnigys at 72v & they get hot pretty quick.)
I need to go back & see what AH you ran last year......My goal is to have full race speed available for the duration of the event. making motor cooling the next weak link.
(hope I can afford it!)
I keep waffling on fairings...I know they could be an advantage.....but I kinda want to compete on equipment as "Like" as the rest of the feild.
Since my last controller explosion I have been practicing on the Gas motored bike. Its only toping out at 27mph but I am having fun scrubbing the tires on the freashly seald asphault parking lot in the industrial park a couple blocks away.
Keep up the good work & keep us posted
How are you feeling with the practice bike & the lack of suspension? I am of the opinion that the weight penalty of a decent suspension would be a HUGE confidence builder on the race set up.
What are your thoughts in that regard?
Batteries-right now I am running 20-25c rated packs (the cheap ones) But I have allways run at least 15ah.(3p) I have yet to experiance voltage sag as you seem to be getting. I would think 3p would be a min requirment. As of today I have 25AH at 66.6v (i can't justify the added voltage on an rc set up.......I have run the big turnigys at 72v & they get hot pretty quick.)
I need to go back & see what AH you ran last year......My goal is to have full race speed available for the duration of the event. making motor cooling the next weak link.
(hope I can afford it!)
I keep waffling on fairings...I know they could be an advantage.....but I kinda want to compete on equipment as "Like" as the rest of the feild.
Since my last controller explosion I have been practicing on the Gas motored bike. Its only toping out at 27mph but I am having fun scrubbing the tires on the freashly seald asphault parking lot in the industrial park a couple blocks away.
Keep up the good work & keep us posted
dogman dan
1 PW
Yeah you wouldn't think 40 or so amps on 30c batteries would sag, that's 8c right? but it does. Not like nicads or lead would sag, but still you can feel it. Honestly, this time out I never looked at the CA to see how much sag. But on the 25 amp dirt bike I have, and seen about 4 volts of sag at 5c.
I'm fairly confident that 15 ah of battery will get you through the race, but to really have the full grunt at the end 20 is more what I think it will take. The lipo is naturally going to drop its voltage gradually as it discharges, so inevitably a small pack will get closer to 3.5v by the end than a big one. So maybe 25 pounds of battery to carry. Doable, but any more will be just too heavy.
The 8 lap heat race will go on less, 15 ah for sure. With my sag fast 5 ah pack, I'm getting 3 miles from 3 ah. so figure 4x3 ah for the race, and 4 more ah for the not murdering the battery in the race. That's 16 Ah. So maybe you could get by with some 2500 mha packs and run 17.5 ah. Again though, 20 will just give you more volts for more laps.
Plus you gotta charge em fast, on a wimpy 110 plug. So say 10 ah for a few practice laps, and then get em charging to use in the main. 15 more ah for the heat race. Then 10 more ah plus the recharged practice pack for the main. 35 ah total. Ouch, more money than I have for sure.
I may have to practice at 48v, then run just half of a heat, showing them enough fast to get let into the main. Then recharge enough to run the main. 45 min charging would be fast enough to run in the first heat race, and have time to recharge. But having enough generator there to power the big charger could be tough, unless you just went out and rented something big. I have a 3000 watt generator, but to fill a big 20 ah lipo pack in 45 min to 1 hour won't be possible with that. Right now, I just have 50 watt chargers that take 90 min. Too slow even if I had 8 of em. I think I could run a couple 200 watt chargers on that generator though. I just can't afford them yet.
Lots to think about. I really hope the numbers improve when I get a 15s pack going. But right now I have no extra money again.
As for suspension, I'd go to a full suspension bike in a heartbeat if was running rear wheel drive. Or I had the right set of clamp on pinch dropouts to put on a stout DH fork. But that front hub pulling in the corners is sooo sweet, I just have to try it one more time, at 72v. For now, I think this is the bike. Only one corner on the track is particularly rough. I do have a set of nicer cheap steel suspension forks, and may just get to welding on them yet. Then I could run my mongoose blackcomb with that fork.
I'm fairly confident that 15 ah of battery will get you through the race, but to really have the full grunt at the end 20 is more what I think it will take. The lipo is naturally going to drop its voltage gradually as it discharges, so inevitably a small pack will get closer to 3.5v by the end than a big one. So maybe 25 pounds of battery to carry. Doable, but any more will be just too heavy.
The 8 lap heat race will go on less, 15 ah for sure. With my sag fast 5 ah pack, I'm getting 3 miles from 3 ah. so figure 4x3 ah for the race, and 4 more ah for the not murdering the battery in the race. That's 16 Ah. So maybe you could get by with some 2500 mha packs and run 17.5 ah. Again though, 20 will just give you more volts for more laps.
Plus you gotta charge em fast, on a wimpy 110 plug. So say 10 ah for a few practice laps, and then get em charging to use in the main. 15 more ah for the heat race. Then 10 more ah plus the recharged practice pack for the main. 35 ah total. Ouch, more money than I have for sure.
I may have to practice at 48v, then run just half of a heat, showing them enough fast to get let into the main. Then recharge enough to run the main. 45 min charging would be fast enough to run in the first heat race, and have time to recharge. But having enough generator there to power the big charger could be tough, unless you just went out and rented something big. I have a 3000 watt generator, but to fill a big 20 ah lipo pack in 45 min to 1 hour won't be possible with that. Right now, I just have 50 watt chargers that take 90 min. Too slow even if I had 8 of em. I think I could run a couple 200 watt chargers on that generator though. I just can't afford them yet.
Lots to think about. I really hope the numbers improve when I get a 15s pack going. But right now I have no extra money again.
As for suspension, I'd go to a full suspension bike in a heartbeat if was running rear wheel drive. Or I had the right set of clamp on pinch dropouts to put on a stout DH fork. But that front hub pulling in the corners is sooo sweet, I just have to try it one more time, at 72v. For now, I think this is the bike. Only one corner on the track is particularly rough. I do have a set of nicer cheap steel suspension forks, and may just get to welding on them yet. Then I could run my mongoose blackcomb with that fork.
Thud
1 MW
dogman,
Have you been tempted yet by the switching power supplys modded into cc chargers? I have a pr of modded S-350 meanwells that I am charging 48v at 350Watts. I haven't timed a charge from "dead" but its pretty quick. Need to assemble the battery medic booster from gary soon for expidited ballancing when required. I have access to a 3kw generator to travel with so that will add to the grid.
I went ahead & welded som adapters to my frame for a suspension fork i have laying around. I have a few ideas for full suspension to be unveiled soon enough in my own thread.
Thanks for the input.
Have you been tempted yet by the switching power supplys modded into cc chargers? I have a pr of modded S-350 meanwells that I am charging 48v at 350Watts. I haven't timed a charge from "dead" but its pretty quick. Need to assemble the battery medic booster from gary soon for expidited ballancing when required. I have access to a 3kw generator to travel with so that will add to the grid.
I went ahead & welded som adapters to my frame for a suspension fork i have laying around. I have a few ideas for full suspension to be unveiled soon enough in my own thread.
Thanks for the input.
dogman dan
1 PW
Info on what that kind of charging can do, how fast for say 10s 20ah, putting in about 10 ah of charge would be good, along with data on how much AC plug it would take to do it. I think my generator is about the equivilant of one 15 amp circuit in a house. I'm still a lipo noob, charging with two of the cheaper chargers. My power supply is a trolling battery and a 12v charger. The battery alone is up to charging 72v 5 ah, so with my small generator I have the capacity to charge 72v 10 ah slowly. My 12 amp automotive charger puts out 6 amps, and does not keep up with two wimpy 50 watt chargers. My 3000 watt generator only puts out 10 amps of 12 DC, but puts out 15 amps of 110v ac.
You'd have a few hours to charge between practice laps and the main. At least an hour between practice and the first heat, and longer if you ran a later heat. Theer could be as much as 2 hours between the first heat they run and the main event. So with a big enough generator and two chargers that put out 200 watts or more, charging 10 ah in 45 min or so should be possible. But I'd still like the idea of fresh, balanced, cherry cells for the main event eh? Still works out to 35 ah of the chosen voltage for that. But reasonably fast charging could make it possible with just the one 20 ah pack.
I was just thinking about having a good strong bracket welded to my cheap triple clamp fork, till I remembered why I canned that idea this spring. It won't fit my good suspension bikes. To get what I want in a suspension fork, I think I need to go the route of clamp on sleeves to bolt onto an alloy suspension fork. Then bolted to that, would be a good clamping dropout. the original drops would be sawed off the forks. To change the tire, you'd remove the dropouts from the fork.
You'd have a few hours to charge between practice laps and the main. At least an hour between practice and the first heat, and longer if you ran a later heat. Theer could be as much as 2 hours between the first heat they run and the main event. So with a big enough generator and two chargers that put out 200 watts or more, charging 10 ah in 45 min or so should be possible. But I'd still like the idea of fresh, balanced, cherry cells for the main event eh? Still works out to 35 ah of the chosen voltage for that. But reasonably fast charging could make it possible with just the one 20 ah pack.
I was just thinking about having a good strong bracket welded to my cheap triple clamp fork, till I remembered why I canned that idea this spring. It won't fit my good suspension bikes. To get what I want in a suspension fork, I think I need to go the route of clamp on sleeves to bolt onto an alloy suspension fork. Then bolted to that, would be a good clamping dropout. the original drops would be sawed off the forks. To change the tire, you'd remove the dropouts from the fork.
dogman dan
1 PW
Well it's been awhile, but finally some more progress on this project. With birthday bux, I finally just got the rest of my lipo, and have enough for 10 ah of either 20s or 24s. Right now the bike is only built for 20s, and I'll run that for practice riding.
I still need to break in the new packs a few cycles before I do any deeper discharges, but fairly soon I should be able to go do a test run simulating a race by braking and accelerating ever few hundered feet, and report how far I can go on 10 ah of 20s under that kind of strain. I am allready pretty convinced that 10 ah is not going to be enough to be fast the whole race. By the end, you'd be at least 5 mph slower if not more. But I hate the weight penalty in handling and the money penalty especially. Not to mention I go over the weight limit for the other race.
I may as well start working on a set of longer battery boxes now I guess. And buy lipo for christmas.
Come race day, I sure hope a few fast laps will get me into the main, because I will need an additional 10 ah of 20s lipo to run an entire qualifying heat. Sitll no word about a halloween race, but if there is one, at least I have a 6 lap bike now for sure.
I have also gotten rid of the funky fairing, that acutally slowed me down. All that remains is a small fairing on the front of the battery box. It may have been the sharp corners on it that caused all the drag.
Soon as I get the batts broke in, and get my shit together a bit, I'll set up a camera on my practice course, and at least show you some video of me whizzing by every lap. I just got a new digital camera for the BD I can set on a tripod, that shoots nice video. too bad you tube doesn't post HD.
I still need to break in the new packs a few cycles before I do any deeper discharges, but fairly soon I should be able to go do a test run simulating a race by braking and accelerating ever few hundered feet, and report how far I can go on 10 ah of 20s under that kind of strain. I am allready pretty convinced that 10 ah is not going to be enough to be fast the whole race. By the end, you'd be at least 5 mph slower if not more. But I hate the weight penalty in handling and the money penalty especially. Not to mention I go over the weight limit for the other race.
I may as well start working on a set of longer battery boxes now I guess. And buy lipo for christmas.
Come race day, I sure hope a few fast laps will get me into the main, because I will need an additional 10 ah of 20s lipo to run an entire qualifying heat. Sitll no word about a halloween race, but if there is one, at least I have a 6 lap bike now for sure.
I have also gotten rid of the funky fairing, that acutally slowed me down. All that remains is a small fairing on the front of the battery box. It may have been the sharp corners on it that caused all the drag.
Soon as I get the batts broke in, and get my shit together a bit, I'll set up a camera on my practice course, and at least show you some video of me whizzing by every lap. I just got a new digital camera for the BD I can set on a tripod, that shoots nice video. too bad you tube doesn't post HD.
dogman dan
1 PW
Well, so much for intending to break in my new lipos slower. 
Intending to go out an run em 5 ah or so, I kept on riding and grinning, till I'd run them down to 3.65v, after 8.6 Ah discharged. Cycle three for the new cells. 
I suppose I should have taken a few more shorter rides, but the demon EV grin possesed me. 
At least I didn't start spinning my head.
But now I finally have some real world data that simulates the kart track in Tucscon. I rode a total of 13 miles, most of it trying as hard as I could to simulate the track from memory. Long run, 25 mph corner, three quick 30 mph corners, 25 mph corner, short run, 25 mph corner, short run 30 mph corner long run, etc etc, and then fit it all in .8 miles. Most likely I made the straigtaways too long, so I started trying to make more stops to even lower speed to really hammer it.
So 13 miles of racing type riding was possible on a 10 ah 20s (72v) HK lipo. I am using the 30s type. The Death race was 10 miles long last year, so the batteries won't die a horrible death before the finish. The power demands of all that braking and accelerating is pretty amazing. The total power used was 656 wh. 50 wh/mi. Peak amps was 46, and most of the time I was seeing 30-35 amps on the CA. The lowest voltage was 72, and at rest the pack was at 73.6. So 2500 watt loads on that battery gave me 1.6v of sag. NOW THAT'S A BATTERY . No wonder the lipo heads have been razzing me for owning pings. :wink:
The performance of the motor was less than I'd hoped, and AJ will not be suprised by that. But it stayed cool enough, About 180-190 F at the finish. The controlller only got warm, as did all my wiring , connectors etc. But top speed of 40 mph on the first lap very quickly settled into 38 mph, and by the end only about 36 mph was possible. Simulating the track, I was very rarely getting above 35 mph. So I need more acceleration for sure. I'll practice a lot at 20s, and most likely pull out 24s for the actual race for more speed. And tweaking the programming of the controller is definitely a possibility.
Right now, after a summer of riding a dirt bike 10-15 mph, 25-35 mph is seeming pretty fast. :lol Obviously this bike won't win the death race. But it may be close to the limit of what I can ride and finish the race. But now that it's built, with practice, maybe I can bump it up to 40 mph on the straights and stay on it. but it will take more than 40 mph top speed on that track to win.
Intending to go out an run em 5 ah or so, I kept on riding and grinning, till I'd run them down to 3.65v, after 8.6 Ah discharged. Cycle three for the new cells. I suppose I should have taken a few more shorter rides, but the demon EV grin possesed me. At least I didn't start spinning my head. But now I finally have some real world data that simulates the kart track in Tucscon. I rode a total of 13 miles, most of it trying as hard as I could to simulate the track from memory. Long run, 25 mph corner, three quick 30 mph corners, 25 mph corner, short run, 25 mph corner, short run 30 mph corner long run, etc etc, and then fit it all in .8 miles. Most likely I made the straigtaways too long, so I started trying to make more stops to even lower speed to really hammer it.
So 13 miles of racing type riding was possible on a 10 ah 20s (72v) HK lipo. I am using the 30s type. The Death race was 10 miles long last year, so the batteries won't die a horrible death before the finish.
The power demands of all that braking and accelerating is pretty amazing. The total power used was 656 wh. 50 wh/mi. Peak amps was 46, and most of the time I was seeing 30-35 amps on the CA. The lowest voltage was 72, and at rest the pack was at 73.6. So 2500 watt loads on that battery gave me 1.6v of sag. NOW THAT'S A BATTERY . No wonder the lipo heads have been razzing me for owning pings. :wink: The performance of the motor was less than I'd hoped, and AJ will not be suprised by that. But it stayed cool enough, About 180-190 F at the finish. The controlller only got warm, as did all my wiring , connectors etc. But top speed of 40 mph on the first lap very quickly settled into 38 mph, and by the end only about 36 mph was possible. Simulating the track, I was very rarely getting above 35 mph. So I need more acceleration for sure. I'll practice a lot at 20s, and most likely pull out 24s for the actual race for more speed. And tweaking the programming of the controller is definitely a possibility.
Right now, after a summer of riding a dirt bike 10-15 mph, 25-35 mph is seeming pretty fast. :lol Obviously this bike won't win the death race. But it may be close to the limit of what I can ride and finish the race. But now that it's built, with practice, maybe I can bump it up to 40 mph on the straights and stay on it. but it will take more than 40 mph top speed on that track to win.
icecube57
10 MW
One thing about cornering is that if you never do corner at all or corner very slowly you never really get the tire to break in to where the rubber can actually grip. Once you start cornering and get your tires properly broken in then you can accelerate into and out of the corners without worrying about traction issues. I corner like mad on my Bell 1.95 Cruiser Slicks. As far as breaking in the lipo... Hell the 1st cycle I furked it up pretty good. The grin got bigger and all prejudice left my body. Its going to take this punishment and like it.... and it did. Some lipos like it nice and easy but if you have 25-30C lipo in a decent configuration of 10AH or more then go ahead and beat up on it.
Ive had the 12 fet Keywin Controller with 4310s on my GM which was a 9x5 vs the 9x7 9C which you are running. I used to beat up on it pretty severely. I had it at a true 72v system for a while doing about 45A. You motor should be alot easier on the controller than my 9x5 GM. So I think you can safely go up to 45A on a 12fet on a 9x7 at 72v. maybe tweak your phase currents to around 105 or 110. The bike would really wake up and you can power out of those corners like a bat out of hell.
Ok... after reading my GM thread I found that I originally was running 130 phase an 57A on the controller. I thought I popped the controller because of the settings being to high but It turns out that the + wire for my CA was laying across the shunt. The shunt got hot enough to melt the insulation off the wire and it created a short. But those settings were running my motor fine. Remember mines was a lower turn count that you 9x7 and I had 4310 mosfets. You have a better controller and a higher wound motor so it should run cooler.
I eventually backed down to 115 and 45. It stayed at that setting until I discontinued the build... unrelated to the controller. So run some figures by Lyen. Im pretty sure the controller will be ok but you will be pushing it at its limit but you remember all the air cooling I had to do for my GM. It took two side cover revisions to get it to where I could do 15-20 miles WOT without going critical. I was peaking around 3500w. 2000w will be about the max I would run into a stock 9C stock for extended periods any higher would surely fry it quickly. Also remember I have alot of voltage sag with my Thudersky pack but I was running true 60v and 72v setups when the pack was under load. Your lipo with the less sever voltage sag can potentially put out more power compounding any heat issues you may have.
Ive had the 12 fet Keywin Controller with 4310s on my GM which was a 9x5 vs the 9x7 9C which you are running. I used to beat up on it pretty severely. I had it at a true 72v system for a while doing about 45A. You motor should be alot easier on the controller than my 9x5 GM. So I think you can safely go up to 45A on a 12fet on a 9x7 at 72v. maybe tweak your phase currents to around 105 or 110. The bike would really wake up and you can power out of those corners like a bat out of hell.
Ok... after reading my GM thread I found that I originally was running 130 phase an 57A on the controller. I thought I popped the controller because of the settings being to high but It turns out that the + wire for my CA was laying across the shunt. The shunt got hot enough to melt the insulation off the wire and it created a short. But those settings were running my motor fine. Remember mines was a lower turn count that you 9x7 and I had 4310 mosfets. You have a better controller and a higher wound motor so it should run cooler.
I eventually backed down to 115 and 45. It stayed at that setting until I discontinued the build... unrelated to the controller. So run some figures by Lyen. Im pretty sure the controller will be ok but you will be pushing it at its limit but you remember all the air cooling I had to do for my GM. It took two side cover revisions to get it to where I could do 15-20 miles WOT without going critical. I was peaking around 3500w. 2000w will be about the max I would run into a stock 9C stock for extended periods any higher would surely fry it quickly. Also remember I have alot of voltage sag with my Thudersky pack but I was running true 60v and 72v setups when the pack was under load. Your lipo with the less sever voltage sag can potentially put out more power compounding any heat issues you may have.
dogman dan
1 PW
I know I can tweak the controller for more for sure. The one I bought is actually opomized for economy. Given the race length, that may be just right. Can't even come in 10th if you DNF. More power means I have to spend more on battery. Right now I have the size right, but maybe just need to go to more volts. 24s gets me close to frying my CA, but I won't have the CA on the bike for the race. So I most likely will run 24s once I get up to cornering speed, and just run till I put 10 miles on the speedo and stop. I can't seem to just hop on the bike and corner at 30 mph. I have to get comfy with it, just like I always had to with skis. Every fall I could strap on skis and go do a black diamond slope. But double black slopes above 40 degrees took a few weeks to warm up to.
The other issue with tweaking the controller is getting the software installed on my computer. My dog brain just starts howling when I try to read those threads on how to do it. I need to take my computer to an engineer friend of mine, and have him get it booted up for me.
I know what you mean about scuffing the tires, I'm likely to wear out these practicing, but for the race I'll want some that are broken in. One issue about practice is there is sand everywhere here in the desert. I know I was leaning farther than normal on that clean track. I take a broom with me to the parking lot I go to to practice cornering.
Still no word on any fall race. But I'm set up for one if it happens. I'll try to get at least some lame video today, the pack is almost charged again.
The other issue with tweaking the controller is getting the software installed on my computer. My dog brain just starts howling when I try to read those threads on how to do it. I need to take my computer to an engineer friend of mine, and have him get it booted up for me.
I know what you mean about scuffing the tires, I'm likely to wear out these practicing, but for the race I'll want some that are broken in. One issue about practice is there is sand everywhere here in the desert. I know I was leaning farther than normal on that clean track. I take a broom with me to the parking lot I go to to practice cornering.
Still no word on any fall race. But I'm set up for one if it happens. I'll try to get at least some lame video today, the pack is almost charged again.
dogman dan
1 PW
Some video from this morning. An unbuilt residential street near my house. Bad camera angle to avoid shooting into the morning sun.
Pretty scary to hit these corners with a curb coming at you any faster than 25 mph. This shows my fastest one, at 29 mph, and a few 27 mph. http://www.youtube.com/watch?v=miw1N379q9E
In the last few seconds, you see the final version of the fairings, just the front of the battery boxes now. The wiring is concealed under a hood, made from a scrap of plastic dog food bag.
Recycle reuse repurpose.
Pretty scary to hit these corners with a curb coming at you any faster than 25 mph. This shows my fastest one, at 29 mph, and a few 27 mph. http://www.youtube.com/watch?v=miw1N379q9E
In the last few seconds, you see the final version of the fairings, just the front of the battery boxes now. The wiring is concealed under a hood, made from a scrap of plastic dog food bag.
Recycle reuse repurpose.
thewmatusmoloki
10 kW
Ha Ha ... good one Mr.Dogster.
I'm watching this thread with great interest.
Taking corners at 47 odd kph on a bicycle would certainly scare the hell out of me.
Best of luck with the build and the race from down under.
You da man.
Matt.
I'm watching this thread with great interest.
Taking corners at 47 odd kph on a bicycle would certainly scare the hell out of me.
Best of luck with the build and the race from down under.
You da man.
Matt.
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