ElectricMotorcycleForum.com
Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: evtricity on November 08, 2015, 12:58:08 PM
-
Some of you may be aware that I race a 2014 Zero SR on the track in the Australian electric Formula Xtreme Challenge. I've created a web site with details about the Zero customisations, race reports and photos.
It's located at http://evtricity.com.au (http://evtricity.com.au). If there's other information about the SR or racing you're interested in let me know.
-
Nice work! I'll have to try and make it along to one of the Winton meets (to spectate). Maybe if I fit that supercharger I can get the SR there.
Sent from my iPhone using Tapatalk
-
The bike looks great! I bet the forced-air cooling solution works well.
If you don't mind my asking, who did your sprockets and triple clamps?
Ray
-
Looks awesome man. If you don't mind I don't want you to give too much away to your competition but would love to know some of the setup specs and stats. If I could survive the plane ride I'd like to go down under some day.
-
Do you ever run into controller temp issues or batt temp issues?
I do have an idea for you about motor cooling something we have been using,pm me
-
Thanks everyone for the positive feedback.
To answer a few of the questions.
rayivers - Danny Ripperton made the custom sprockets and top triple clamp. You can find him on DIY Electric Car. I run an RK 428SO chain on the sprockets he made. He has all the software and machinery to cut different size sprockets if you're interested.
rayivers - the 40mm EDF fan helps a little bit with cooling but not as much as I hoped. So the motor still overheats (goes over 130C) after about 7-8 minutes at race pace and cuts the power to a Sevcon size 4 controller equivalent (Zero S) which prevents the motor from overheating any further.
Cortezdtv - I have never had a problem with overheating the controller however battery overheating is also an issue on track days and I have pushed it as high as 56C which resulted in the bike shutting down until I got it down to 55C. When on the track the bike heats approximately 1C per minute. So I could ride maybe 35-40 minutes on the track (starting at 15-20C) before hitting battery thermal limits. Since track sessions are only 15-20 minutes at most and there's an hour between sessions so the battery can cool a few degrees I can usually get about 90 minutes on the bike over an 8 hour day and leave the track with the battery temp reading over 50C. With the cells packed so densely together they do tend to retain heat and it's very hard to cool them with a fan/ice etc. I have considered forcing some air into the battery box but it's not a problem on race days (where there is less track time) only on ride days where if I miss the last session of the day it's not a disaster.
Cortezdtv - Happy to hear alternate options about motor cooling but the best option at this stage would probably be the new 2016 Zero motor.
PhreaK- Will look to race at Winton again next year and can provide a free entry ticket to make the long drive/ride a bit cheaper.
NEW2elec - In terms of setup specs and stats let me know what you're interested in. I'm happy to share the controller changes I have made - they're mostly around increasing the torque at higher RPMs.
-
Thanks for the sprocket / TC info - much appreciated! At some point I may look into 48mm front forks and a different TC offset, so it would great to have a source for custom TC's if Danny has the time.
Regarding the motor cooling - it seems to me that in a PMAC motor, the magnets themselves are by far the most vulnerable to overheating damage, which apparently is the main reason for the new IPM motor design. Unfortunately, the temp sensor is in the stationary assembly, so even if the rotor is blasted with ambient air - Harlan told me it can shoot out of a ventilated motor several feet - the coils & sensor are still hot, so the hi-temp protection kicks in anyway even though the rotor is surely much cooler. Has anyone tried - in a ventilated-rotor motor only - raising the temp limit, or modifying resistance in the sensor circuit to achieve the same thing? I'd think a relatively small change here might make a big difference in both onset and recovery times of the protection circuit. I don't know what the temp ratings of the Motenergy coils are, but I've seen air-cooled transformers on the ship rated for 200C continuous (nearly 400F) that ran smoking hot for years on end without failures.
Ray
-
1 24 oz co2 bottle can effectively bring the motor to basically ambiant temp and give you a "fresh" start but probably not factory endorced
-
When i was racing a EV we used to build a duct around the motor and the have a seperate chamber with dry ice and we would force air from the chamber thru the motor. It worked fairly well. We did it for many years with the same motor, and we never cracked the motor housing due to a thermal shock. Might be worth a try with a vented motor.
-
The bike looks great!
I am considering installing a front cowl fixed to the frame of my 15 SR (not to the forks). I was curious how you got the front fairing stay onto the neck of the bike. Specifically, how were the fairing stay tabs installed? Was it done by welding (TIG or oxy acy), aluminum brazing/soldering, metal adhesives or some other process?
I'm looking for a low temperature process and I've seen some processes for 6061-t6 aluminum (what I think is the grade used by zero) that maybe very applicable but it would be great to get some feedback from someone who has already done it.
-
We simply drilled and tapped two holes at the top and bottom at the front of the fork steerer (there are two bulges that come forward at the top and bottom). There's enough alloy there to be able to get some good sized bolts in there. Can post some photos if that helps.
You shouldn't have to add anything onto the frame, just need to make some custom brackets to fit the fairing and attach to the two new bolts in the fork steerer.
Sent from my LG-D855 using Tapatalk
-
Some photos would really be appreciated. There are a lot of people interested in putting fairing on their bikes.
-
The first two photos below are of the top bolt and then the bottom bolt. Both are screwed into drilled and tapped holes in the fork steerer.
You can see the silver alloy brackets coming off each bolt.
The third photo is a bit busy but you can see the two allow brackets coming from the top and bottom bolts on the left and then bolts to a U shape bracket which attaches to either side of the fairing half way up the windscreen.
-
We simply drilled and tapped two holes at the top and bottom at the front of the fork steerer (there are two bulges that come forward at the top and bottom). There's enough alloy there to be able to get some good sized bolts in there. Can post some photos if that helps.
You shouldn't have to add anything onto the frame, just need to make some custom brackets to fit the fairing and attach to the two new bolts in the fork steerer.
Is it pretty solid? How much does the fairing shake around when you go over bumps?
Is the tank metal? Do you have a power tank battery under there? Do you know how much the bike weighs the way you have it configured?
-
Awesome, I'd say that's as low temp as you can get. Never noticed that the steering limiter is also up top! How convenient...
Thanks for the info!
-
Is it pretty solid? How much does the fairing shake around when you go over bumps?
Is the tank metal? Do you have a power tank battery under there? Do you know how much the bike weighs the way you have it configured?
Yes, the fairing is very solid with minimal vibration. It also attaches onto some RG Racing frame sliders on each side as well as along the bottom of the frame on each side of the battery. I have a GoPro fitted on the U bracket and through the screen and it produces pretty smooth video. Videos at https://www.youtube.com/channel/UCtxWXT36o2YDEeQgO7V0saQ (https://www.youtube.com/channel/UCtxWXT36o2YDEeQgO7V0saQ)
Tank is a fibreglass CBR10000RR 2008 model. No powertank or onboard charging - I use 2 x 2kW TC chargers offboard via fast charge port.
The bike weighs 175kg in race setup and can be switched back to run on the road in 90 minutes (stock headlight, stock tail section, mirrors etc).
-
The SR is a great bike, but how are you going to get a 50kw motor to keep up with the 120+kw motor in the bike Dr. Chris built and the others?
-
You're not on a fast circuit. But Chris' Voltron Evo still hasn't beaten the lap record for a Ninja 300 at some tracks in Australia so horsepower isn't everything. For me the Zero SR is a way to learn racing. I'm planning on moving to a much more competitive bike in 2016 and 2017 and getting a fast rider onboard.
Electric bike racing will always be small if people have to build their own bikes like the three bikes that blow me away at every race in Australia.
However, the Zero SR was the fastest production electric available in Australia in 2014 (and 2015) so I bought one and took the opportunity to see how it measures up on the track. I really hope that Zero's form the basis of an introductory or junior racing class like the Ninja 300s in the next 5-10 years. However the main game now is to beat the gas bikes and with a much more powerful production bike available in Australia next year that will happen in earnest in 2016 and 2017.
-
A quick follow up to a question about overheating on my 2014 SR on the track.
I did a ride day at Sydney Motorsport Park (GP Circuit) yesterday (ambient temp 20-26C and mostly cloudy) and max bike temps were as follows:
Battery pack = 54'C - I shorten the sessions to keep battery temp below 55-56'C where I have had the bike cut-off previously
Controller = 64'C - note the Sevcon spec says it derates at 80'C and restricts time at high power output between 25'C and 80'C
Motor = 136'C - noticeable thermal cutback starts around 120'C (after 4-5 minutes on the track)
Battery temperature increase/decrease rates are as follows (approximate):
When on track - pack temp increases 0.8-1.2'C per minute (rate of increase is greater at lower battery temps)
When off track - pack temp decreases 1-3'C per hour (rate of decrease is greater at higher battery temps)
So with a starting pack temp of 25'C and 2 x 15 minute sessions with a 45 minute break in between, the pack would be very close (25'C + 2 x 15'C - 2'C = 53'C) to the 55'C limits (charging etc).
Average speed on this track for me is just shy of 120kph including 60kph corners and 180kph straight.
I did a track day the previous week on the South Circuit at SMSP which is shorter and twistier with average speed about 95kph. Battery temperature increase was only 0.6'C per minute.
No doubt the IPM motor design will help with motor overheating but it's worth noting that battery pack design also limits performance on track days. The controller's thermal limits are not being reached and do not seem to be restricting performance (there is a motor torque cutback map in the controller that does that).
So what does this all mean?
For those who wish to take their Zero on the track - go for it but take your phone and keep an eye on the battery temp after each session.
-
does it cool any faster if you spray the battery case down with water? or is all the heat "stuck" inside the pack, with no easy thermal path out of there?
-
does it cool any faster if you spray the battery case down with water? or is all the heat "stuck" inside the pack, with no easy thermal path out of there?
Given the mass and density of the battery I doubt that cooling the case with water, ice or air will really do much i.e. cool the outer cells only and then just a little.
If you removed the plastic (or in my case fibreglass) tank and have some ice sitting on top of the case that would help a little but to be effective I'd need to get the heat pushed out of the battery box either through ventilating the battery box or with liquid cooling. I'm not keen to open the battery box up to do this but the limit on track time of the battery overheating is getting frustrating. Perhaps if I was running the smaller battery pack (e.g. an 8.5kWh on the 2014s) where there is only 3 of a possible 4 modules inside the case there would be room for ventilating fans and at least 2 of the 3 bricks would have an exposed side to try and cool.
Blowing air on from the outside it is easy to do and I do that to a small degree i.e. I run a fan between motor and battery pack to reduce heat transfer from the motor. I also have run ducting and recently an EDF into the motor itself which helps cool the motor both on and off the track.
That reminds me that I should do some side by side comparisons to compare the cooling benefit of the ventilated motor with the EDF on versus off, both on and off the track and post the results.
-
My crazy head has me thinking about flooding the case with mineral oil to get the heat out.... lol
Flooded cooled battery.
-
Perhaps if I was running the smaller battery pack (e.g. an 8.5kWh on the 2014s) where there is only 3 of a possible 4 modules inside the case there would be room for ventilating fans and at least 2 of the 3 bricks would have an exposed side to try and cool.
I would expect this to have a negative over all affect on battery over heating even though you would be adding ventilation. When the controller draws current, each brick has to provide less current if you have 4 batteries instead of 3. Battery temperature is largely driven by discharge rate and the discharge rate per brick will be higher with 3 batteries than with 4. In fact, adding a power tank should allow longer rides before over heating because you have added a 5th brick so the discharge rate per brick is reduced even more.
For example, if the controller is trying to pull 400 amps and you have 3 bricks then each brick needs to provide 133 amps. If you have 4 bricks each brick only needs to provide 100 amps and if you add a 5th brick then each brick only needs to provide 80 amps.
Of course, adding a power tank means additional weight and a higher CG.
-
Also, do you use regen when racing? Regen adds a lot of heat to the motor and the batteries. Setting regen to zero for neutral throttle and braking should help with heat.
-
Regen is turned off on the faster tracks but I sometimes run it on the slower tracks.
I appreciate that the smaller pack would mean more current and greater heat while riding so it's not really an option on the 2014 unless I want to cut the power down with the net result being I'd go slower on a lighter bike!!!
However, I think it may be a valid option with the 2016 9.8kWh battery pack and their 29A cells and 10C peak discharge rate. Perhaps the 2016 SR's 13.0kWh battery pack is slightly less prone to overheating due to its greater capacity but I'm not aware of anyone taking one to the track yet.
Since the SR motor appears to have reached it development limit for performance and I don't need the range of an 11.4kWh battery pack for the track, reducing weight via a smaller pack seemed a reasonable option to improve performance.
Guess I'm a couple years early on expecting sports bike like performance from a Zero SR despite all my efforts to try and make it so.
-
Have you tried different fairings? I know you mounted a sport fairing but have you tried to really get the coefficient of drag down?
If you can reduce the coefficient of drag the motor won't need as much juice and the batteries won't get as hot.
-
Have you tried different fairings? I know you mounted a sport fairing but have you tried to really get the coefficient of drag down?
If you can reduce the coefficient of drag the motor won't need as much juice and the batteries won't get as hot.
No, haven't tried different fairings - it was a relatively expensive and time consuming exercise getting the RSV4 ones, customising them to fit the Zero and then painting.
I'm not sure how you can tell the CD of a bike/fairing unless you take it a wind tunnel!
I appreciate the aero benefits of the Vetter-style fairings but they're ugly as so that's not really an option. I'm trying to get respect for electric bikes at the track so trying to have the bike still look sharp is important.
Thanks for the suggestions though, feeling a bit down today about the SR. Probably didn't help I was on track with some of Australia's leading racers on Monday on Supersport and Superbikes on a track best suited to high power bikes. Perhaps moving to an LS218 will be the best way forward to showcase electric bikes on the track.
-
Yeah, I think you would have to go to a wind tunnel to know the exact numbers but I really just meant trying to improve on aero.
For example, if you fill in the area where the radiator would be on an ICE you can improve aero. In the pictures I was looking at it looked you just left that area open allowing air to hit the monolith. If you fill as much of that area as possible while still leaving room for the forks to move you will improve aero. Making a panel that covers that area with somewhat of a bubble shape will help without sacrificing looks. You could also consider a larger front fender that improves aero. That would also have a minimal degradation in cool factor.
Someone posted this pic on another thread....a front fender like this one would still look good.
(http://www.airtech-streamlining.com/images/hayabusalandspeedfairings2.jpg)
-
You can experimentally determine drag and rolling resistance.
http://m.instructables.com/id/Measure-the-drag-coefficient-of-your-car/
-
You can experimentally determine drag and rolling resistance.
http://m.instructables.com/id/Measure-the-drag-coefficient-of-your-car/
Interesting read. My take away was don't bother to actually calculate Cd. Just measure the time it takes to coast from speed A to Speed B then repeat after making the mod and compare the results.
If you want to compare performance of a vehicle before and after making mods, the change in coast down time itself is MUCH more meaningful than any change in Cd or Crr extracted from the coast down data.
Sent from my XT1060 using Tapatalk
-
Perhaps moving to an LS218 will be the best way forward to showcase electric bikes on the track.
If you do this, I'm turning up to your first track day with it so I can drool over it like a teenage Bieber fan.
-
+1 on the LS218! It would be fun watching your footage smoking the ICE bikes. I'd love to see how that thing performs on the track. Great work by the way. I'm sure you've made a great impression already so don't be too disheartened. I look forward to checking out your website. :-)