# Kart (Go-Kart) Project



## EVKarter (Jun 22, 2011)

Here's a graph of speed V time at the local track. Not an especially quick lap so it might have been damp but it will give you an idea of time spent accelerating. Here's my findings, hopefully they help somewhat..

1) Total time spent "on the power" looks to be 31secs over the course of a 49sec lap: 63%. My guess off the top of my head wasnt so bad!

2) Longest single amount of time "on the power" is 8seconds. This may not be obvious from the graph as it starts at 42secs (Last hairpin) through a flat out corner (last turn) and continues to 1sec or so to the next lap. This is the area marked (rather crudely) with thick red lines on the map.

3) Most of this time under power is WFO. Progressive\partial throttle probably counts for a total of 2 seconds during the lap at the most. The rest is pedal to the stop (at least with the IC motor)


Speed V Time Graph...












Speed V Distance Graph:










Track map (www.smpmn.com):










So what's it going to take to make a 440lb projectile (total target weight incl driver around 200lbs) achieve this? There are some elevation changes involved, which I can mark on the map if needed.


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## steven4601 (Nov 11, 2010)

Thats a pretty quick vehicle. Do i read correctly 400lbs, 4 seconds to 65mph? approx 1.2G till 30mph? 

Assuming 77% transmission efficiency, you'll need 20kw motor shaft power to match this.


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## EVKarter (Jun 22, 2011)

steven4601 said:


> Thats a pretty quick vehicle. Do i read correctly 400lbs, 4 seconds to 65mph? approx 1.2G till 30mph?
> 
> Assuming 77% transmission efficiency, you'll need 20kw motor shaft power to match this.


Thanks for chiming in Steven. Yeah it moves pretty decent. With the right gearing and a good launch 0-60 is sub 4secs. Cornering and braking are the most impressive part, usually around 3G, sometimes in excess of this. Here's an onboard video with some data from a datalogger overlayed:






One thing that I forgot to mention is that I change gears (while accelerating) a total of 14-15 times per lap. Each shift represents around .2s where I am not using the motor to accelerate the vehicle. So this would work to the EV's advantage I would imagine.

When you say 20KW motor, is that based on the assumption that it would be getting "overworked" (whats the correct term?) or simply using it within its design intent? Do you have any 20KW recommendations? Any battery musings? On my budget I guess I would have to go LA, but if I could use these and stay in budget I think that would be awesome: http://currentevtech.com/Lithium-Batteries/CALB/CALB-60ah-cell-p29.html

Am I correct in assuming that I need a capacity of approx 3.33KW/hrs (lets call it 3.5 for simplicity) to run this thing for approx 10mins? My logic (possibly flawed) is simply 1/6th of 20KWh, ie 10 mins. Given that I'm on power only 60% of the time on a lap, I am hoping that 3500 KWh is reasonable to attain 10mins of track time?


_/edit_ so in trying to figure out how many batteries I need for 3.5KWh I think this is going to be tough to meet to put it mildy. If I take the batteries I listed above, 60AH @ 3.2v = 192 KWh per battery. Meaning I need approx 18batteries at $82 each, $1476? Thats not so bad, a little out of budget, but it seems that it might be feasible to DIY a kart with decent peformance for reasonable cost. 90lbs in batteries though. OUCH!
How poor are my calculations?


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## steven4601 (Nov 11, 2010)

20kW is shaft power. Does not mean how the motor is used/rated.

assumption, DC motor 20kW / 80% eff / 0.93% eff drive = 26kW from traction battery. 

kWh estimation using a 0.6 on factor for acceleration. Assuming motor never spins down under its maximum output power (rpms too low to produce 20kw) then you'll need 
26kw * 0.6 * 10/60minutes = 2.6kWh.
2.6kWh is about 28kg of LifePo4. (assuming 100% dod / ruined batteries)


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## major (Apr 4, 2008)

EVKarter said:


> While certainly not original, I'd like to give this a go, get some pointers from you guys and learn something about EV. I've read around the forums here as well as wiki but I'm still a little confused on where to start. The idea of converting a car to EV crossed my mind, but I figured this would be more fun and probably a little cheaper.
> 
> Currently the kart weighs a smidge under 200lbs without driver. This includes fuel, motor etc.
> It has a kart specific 125cc 2 stroke 6speed motor that puts out approx 45-50BHP. Lets call it 35 (IC) KW for now. Drive is currently transmitted via a 428 pitch chain.
> ...


Here's an eKart I help build this year.





































I'll bet it could keep up with your gasser  A buddy took it to an EV autocross a few weeks ago and took first place. Beat 2 Teslas by 3 seconds on a 25 second course 

Go electric dude.

major


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## Yabert (Feb 7, 2010)

Hi

For this kind of project, you need a better power weight ratio than Calb cells.
It's in the range of lipo or A123 cells. 

So, you need:

Powerful cells: A123 (2.4Kw / Kg) or Turnigy nano-tech (claim 7 Kw / Kg).... 1500-3000$ http://www.hobbyking.com/hobbycity/store/uh_viewItem.asp?idProduct=14614

Light motor: AGNI B 95R or maybe EMC-RT200..... 900-1500$ http://www.electricmotorsport.com/store/ems_ev_parts_motors_agni_b95r.php

Powerfull controller: Kelly KDHD 600 to 1200A, Soliton1, Warpdrive or Zilla..... 900-3000$

Here a friend of mine with his getto style kart (A123 cells, zilla 1000A and forklift motor(350 lbs+ without driver, 0-60 sub 4 sec.)): http://www.youtube.com/watch?v=bERjkSTYOdU


Good luck... it's possible, but for 4-5K$


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## EVKarter (Jun 22, 2011)

Thats quite a contraption Major! Belts and rollcages are alien to me! I'd guess my "gasser" would compare favorably on a sprint track over the course of a race, which is what its designed for. It's close to the tesla on acceleration but I would imagine it would destroy it in the turns and braking, in race trim I'm at 385lbs with driver and a full tank. The other thing is that it cost me <$1800! Your post got me thinking I might be better off AutoX'ing it though. Hmmm. More achievable since its a really short run.
Can you post some info on your project, any links to it on here?


Yabert, thanks for that info. It helps a lot. $4500 is way more than I'm able to spend at this stage, but its still good to know what a stage II might look like. 350Lbs + driver is hard to stomach for me though. I come from a world where I would have 75Hp on a 150cc alky motor and a total weight of 340lbs including driver!!! I can't imagine trying to dial that thing in on a twisty track! Out of curiosity, how much the electrics cost for the "FrankenForkliftKart"?

I'll have to make some tough choices and compromises that's for sure....
This one looks interesting, aside from the misunderstanding of basic kart handling principles! Electrically it looks pretty neat though...


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## Yabert (Feb 7, 2010)

I'm sorry, I forgot to said you than my friend kart is a cheap one.... in fact, his kart frame and his motor is really heavy.

With light frame, 25 lbs motor and 50-60 lbs battery pack, you can be in the race....... for few laps....


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## major (Apr 4, 2008)

EVKarter said:


> Thats quite a contraption Major! Belts and rollcages are alien to me! I'd guess my "gasser" would compare favorably on a sprint track over the course of a race, which is what its designed for. It's close to the tesla on acceleration but I would imagine it would destroy it in the turns and braking, in race trim I'm at 385lbs with driver and a full tank. The other thing is that it cost me <$1800! Your post got me thinking I might be better off AutoX'ing it though. Hmmm. More achievable since its a really short run.
> Can you post some info on your project, any links to it on here?


Yep, more later. We ran 70 laps of a 100 lap race, swapped batteries in 7 seconds and back out for the finish. Grand prix course about 1/3rd mile with 8 or 9 turns. Had about 30 eKarts on the grid


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## EVKarter (Jun 22, 2011)

Yabert said:


> I'm sorry, I forgot to said you than my friend kart is a cheap one.... in fact, his kart frame and his motor is really heavy.
> 
> With light frame, 25 lbs motor and 50-60 lbs battery pack, you can be in the race....... for few laps....


If I can get it to run for 10mins of "track time", that should do it. Theres a class called FX (Formula eXtreme) at the track which is basically run what ya brung. I think the heats are only 6laps with the final being 10, so 6mins might even be enough. All my races have been nationals or regionals so I haven't actually raced at this track, only tested.

_*Major*_, do post more when you get time.



So how feasible does this look:

* 20KW (26KWh drain? on cells) for total of say 5mins (short race, using full power 60% of time).
* Total weight of motor, cables, batteries and controller under 100lbs.
* Budget around $1500.

Failing this, what's your best estimation on how close I can get for 1500? I'm happy to use used motors or controllers.


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## major (Apr 4, 2008)

EVKarter said:


> _*Major*_, do post more when you get time.


This one was built on the cheap.....except for the battery 













http://www.diyelectriccar.com/forums/showthread.php/kokam-go-cart-kokart-37818.html?highlight=kokart


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## EVKarter (Jun 22, 2011)

major said:


> This one was built on the cheap.....except for the battery
> 
> http://www.diyelectriccar.com/forums/showthread.php/kokam-go-cart-kokart-37818.html?highlight=kokart


Nice, I just watched the drifting vid and laughed out loud. How would the "snazzier" battery setup cost?


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## Tatsushige (Mar 24, 2011)

I was watching a Youtube Video of a 70Kw Electric Cart, Love to build one as in Japan we have EKR (Electric Kart Racing) since 2001


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## major (Apr 4, 2008)

EVKarter said:


> _*Major*_, do post more when you get time.
> 
> So how feasible does this look:
> 
> ...


Hi EVK,

The eKart in post #6 competed here http://www.evgrandprix.org/ at Indianapolis Motor Speedway (infield) last May. I wish they would update the website, but summer break I guess. That organization is looking to expand nationwide. Actually had several eKart teams from UK. If you know of any universities, colleges or tech schools with interest, have them follow link on web site.

Our eKart (BGSU #9) ran an AC15 with Curtis and Lithium Poly (Ener1) batteries. Nominal 45V system. Limited to 14 kW at battery by rule.

Sponsorship helped big time, especially with battery. 

The old cart was called the logsplitter because it came to us years ago with an old B&S engine. Again years ago, we put a 6.6" series DC motor on it, size of a golf cart motor. Used an "on-hand" 275A Curtis and left over PbAcid batteries at 48V. Four 40lb batteries made it real heavy, and frame sucked, but it was quick. Later I happened into a few LiPoly cells and tested them on the Kart, hence KoKart. Still 48V, but like 120lb lighter with twice the range 

Sure....your budget looks doable for an eKart. I'd suggest a 6.6" series motor, maybe the 400A controller and 4 good AGMs. For parts, check with the site sponsors here. Also electricmotorsports and thunderstruck. But don't let them talk you into a PM motor  A SepEx motor would also be nice. Get regen. We had Regen with the AC system.

Of course you really need Lithium batteries and more power. But get your efeet wet first and you'll be better prepared to take the Li leap.

Regards,

major


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## EVKarter (Jun 22, 2011)

> Sure....your budget looks doable for an eKart. I'd suggest a 6.6" series motor, maybe the 400A controller and 4 good AGMs. For parts, check with the site sponsors here. Also electricmotorsports and thunderstruck. But don't let them talk you into a PM motor A SepEx motor would also be nice. Get regen. We had Regen with the AC system.


Can you break this down into noobie language for me?

Shame they have to run those silly rollcages in the EV race. Interesting that they have no rules regarding a solid rear axle. I see they had a team from Ireland, I'm originally from Dublin. Any idea what school it was? I checked out the videos on the website too and they helped me a little with the basics of the concepts.

This motor looks rather beastie with 30KW peak (96V): http://www.thunderstruck-ev.com/index.php?dispatch=products.view&product_id=147
Are there any consumer battery packs worth stripping for cells say from cordless drills etc?
What kind of batteries am I looking at to run this beast for the time I need? How does one go about upping the voltage to the motor above what the batteries are supplying at the sacrifice of run time, in this case 96V peak?

Do the battery offerings here seem like good value?: http://www.battlepack.com/LiFEPO4.asp
I just realized a charger is going to set me back a pretty penny. I think I'll focus on decent performance first and range second. By that I mean I think I'll go with quality over quanitiy in the battery department. Hopefully I can add packs to in order to extend range as I need to and as I have funds to do so. Even 4mins of "motor running" is almost 10 laps, if I could get that with reasonable performance and light weight I think I would be pretty happy. Charging time is the other part I guess.

What Amperage of controller am I looking at for this? I've spotted a couple of used 300A on eBay for around 175 but I think I need something closer to 500A correct.

Thanks for all the help guys...


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## major (Apr 4, 2008)

EVKarter said:


> major said:
> 
> 
> > Sure....your budget looks doable for an eKart. I'd suggest a 6.6" series motor, maybe the 400A controller and 4 good AGMs. For parts, check with the site sponsors here. Also electricmotorsports and thunderstruck. But don't let them talk you into a PM motor  A SepEx motor would also be nice. Get regen. We had Regen with the AC system.
> ...


Series wound DC motor is most common for EV converters and simplest to mate with controller. Also get you the most starting torque. But does have overspeed issue at no load, so a speed sensor and cutoff circuit should be used in case you throw a chain. AC, PM and SepEx don't have this overspeed issue.

And 6.6" is the motor frame diameter.

400A is the current limit of the controller which also defines the peak power, which is an intermittent condition only.

AGM is absorbed glass mat lead acid. Non spillable (sealed). Has the highest power density for PbAcid type batteries. Meaning light weight high power can be had but range will suffer. AGM is expensive for PbAcid, but cheaper than Lithium. Get deep cycle if you want more than 40 charge cycles. Care with charging needed. Optima, Hawker, Genesis brands come to mind.

PM = Permanent Magnet. Look good on surface, but suffer in durability compared to wound field motors. Good perhaps for efficiency long duration racing, but can melt with balls out accels 8 times a lap 

Again, I suggest you start out your electric adventure with a modest build. Keep voltage low. Weight will undoubtedly be more than you want, but the electric torque will tend to equalize that. With a low voltage Pb battery the charger will be reasonable cost. Maybe use trolling charger or from golf cart.

Regards,

major


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## EVKarter (Jun 22, 2011)

Damit major you be slowin' me down! It makes sense though. I really worry about buyers remorse if I get FLAs or AGMs and I find myself seriously considering Li with shorter running time to avoid it. Is there particular AGM pack off the top of your head that you would reccomend?

Haul that kart of yours up to MN in October and we can do some laps  When this all finally comes to fruition ill to a side-by-side onboard video of Gasser V Electon Nommer.


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## Yabert (Feb 7, 2010)

major said:


> PM = Permanent Magnet. Look good on surface, but suffer in durability compared to wound field motors.


I agree with major in this motor fact

A 6.7" DC series motor suffers from its overweight, but can tolerate more overload.
They can weight 50-60 lbs but can generate more than 100 lbs-ft (200-300 at wheels) of torque with proper controller.
Rebuilding an used forklift pump motor for 100-200$ can be a good choise.

You can probably learn about battery with a really small lifepo4 or lipo pack. 
Something like 74v 8Ah (Turnigy nano-tech (only 12 lbs, 520$)) can give you 25-30 hp (with proper controller) for around 1-2 min.
But lipo it's the hard way to learn.... AGM lead is the easy way.


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## EVKarter (Jun 22, 2011)

Yabert said:


> I agree with major in this motor fact
> 
> A 6.7" DC series motor suffers from its overweight, but can tolerate more overload.
> They can weight 50-60 lbs but can generate more than 100 lbs-ft (200-300 at wheels) of torque with proper controller.
> Rebuilding an used forklift pump motor for 100-200$ can be a good choise.


This certainly sounds like good value for money. The weight is concerning though, handling is pretty important for me.



Yabert said:


> You can probably learn about battery with a really small lifepo4 or lipo pack.
> Something like 74v 8Ah (Turnigy nano-tech (only 12 lbs, 520$)) can give you 25-30 hp (with proper controller) for around 1-2 min.
> But lipo it's the hard way to learn.... AGM lead is the easy way.


When you say "learn" is it that the setup is that more complicated with Li? 25 or so HP for 3-4mins at around $1000 for Turnigy batteries is tolerable I think. 24lbs would be awesome!
Shame about the PM motors, they seem to offer excellent power/weight ratios.


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## major (Apr 4, 2008)

EVKarter said:


> Damit major you be slowin' me down! It makes sense though. I really worry about buyers remorse if I get FLAs or AGMs and I find myself seriously considering Li with shorter running time to avoid it. Is there particular AGM pack off the top of your head that you would reccomend?
> 
> Haul that kart of yours up to MN in October and we can do some laps


Hi EVK,

With Lithium you likely need to build your own battery from purchased cells. Those cylindrical cells need a spot welder. The big prismatics likely won't give you the desired power density. The pouch cells would likely be the way to go, but need some expertise to put together. And then the whole BMS thing. And charging. And cost. And safety.....just had a TTXGP quarter million dollar bike burn to the ground 









Back to the AGMs. I don't make product recommendations if I can help it. But here are references for ya 

http://www.batterystore.com/Yuasa/YuasaPDF/GenesisGuide.pdf 

http://www.odysseybatteries.com/battery/pc680.htm 

For power you need low internal resistance in the battery. For range, you need ampere hours (Ah).

Hope that helps,

major


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## EVKarter (Jun 22, 2011)

So when I look at motors and it specifies x amount of x amps for x time peak, what is the assumed time (cooldown?) between peaks? Is it a thermal limit? I'm thinking this is going to be critical to my motor selection?

Take the ME1003 as an example (overlook that its a PM for now)
http://www.evdrives.com/mars_motor_me1003.html

_"For voltages from 12 to 72 VDC input and 200 amps continuous (500 amps for 1 minute) @ 72 Volts._"

Heres what the "power application pattern" would rougly probably look like. Time in seconds: *Red = Full Power Blue = Coast Black = Partial Power*

*4s 
4s
3s
4s
3s
2s
3s
3s
2s
5s
1s
1s
2s
8s



*I'm struggling a little (well, a lot) with my math here, hopefully someone can help....

Say I get $640 worth of these (Total of 10 batteries): http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=11940
Wire them up to give me 74V @ 12AH (I think)
Assuming 25% DOD, how long can I expect to get if I pull 26KW from them?


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## frodus (Apr 12, 2008)

10 of those is 14.8V a pack, 10 packs at 6Ah per pack, 2 in parallel would be 888Wh. Meaning, you can give 888W in one hour at 1C (12A for the stated pack). You'll be using much more than that, 0ver 20C, so expect to get maybe half of that energy out of the cell, 444Wh.

So for 26kW, you could pull that for, oh, a minute.


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## EVKarter (Jun 22, 2011)

frodus said:


> So for 26kW, you could pull that for, oh, a minute.


OK, thats kinda what I was thinking. So two laps per $640. Wicked LOL. Am I correct in saying that in addition to the capacity limitation, these the battery packs cannot release the energy required fast enough?


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## frodus (Apr 12, 2008)

and a severely decreased battery life. Don't expect too many cycles out of that pack. Consider doubling that to 24Ah at least.

And you'll need larger cables on those batteries, those will melt at that C rate


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## major (Apr 4, 2008)

EVKarter said:


> Heres what the "power application pattern" would rougly probably look like. Time in seconds: *Red = Full Power Blue = Coast Black = Partial Power*
> 
> *4s *
> *4s*
> ...


It's call duty cycle rating. And the motor companies don't rate them that way, well, except for fork lift pump motors. So you're left buying that PM motor and burning the brushes and comm while the windings stay nice and shiny.

So it sounds like you're not taking my advice on much here. That's o.k. Learning from your own mistakes is more convincing. But also more expensive.

Good luck 

major


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## EVKarter (Jun 22, 2011)

major said:


> So it sounds like you're not taking my advice on much here. That's o.k. Learning from your own mistakes is more convincing. But also more expensive.


I'm just bouncing ideas around and learning, I'm taking everything into account inlcuding what you have posted, here and in other threads. Sorry if it seems otherwise. Remember, I haven't bought anything yet! Like I say my main fear is spending money and having buyers remorse afterwards, especially regarding batteries.

What non-PM motors meet my requirement in terms of power and weight? I don't think I've seen any, I may have just missed them.

Travis thanks for your input on those batteries.


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## Yabert (Feb 7, 2010)

EVKarter said:


> What non-PM motors meet my requirement in terms of power and weight? I don't think I've seen any, I may have just missed them.


Here (exept for the weight 64lbs): http://www.diyelectriccar.com/forums/showthread.php/suzuki-drz-sm-2005-electric-48239.html

You can find similar (and better) motor used in a forklift. Try to find motor with 2 pairs of brush (4 poles and 8 brush). They can take more amps.
Mine become only barely warm after few 700A acceleration during a 5-6 min test.


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## EVKarter (Jun 22, 2011)

Yabert said:


> Here (exept for the weight 64lbs): http://www.diyelectriccar.com/forums/showthread.php/suzuki-drz-sm-2005-electric-48239.html
> 
> You can find similar (and better) motor used in a forklift. Try to find motor with 2 pairs of brush (4 poles and 8 brush). They can take more amps.
> Mine become only barely warm after few 700A acceleration during a 5-6 min test.



That quite an impressive project! It sucks these non PM motors are so heavy. If I was drag racing I'd say yeah but 64lbs + batteries is going to weigh in pretty heafty and handle like a drunk pig on rollerskates.


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## EVKarter (Jun 22, 2011)

ev_nred said:


> nice project!! was that not a kf1 kart before? or? ever thought of some sort of KERE? how about starting an electric karting class? I currently I am in honda junior and am going to rotax dd2 next year Ive looked at the cost and they are 3.5k for engine plus a rebuild every 50 hours!
> anyways, what about 39 of these http://currentevtech.com/Lithium-Batteries/Thundersky/Thundersky-40ah-cell-p24.html how long well they last at full 20c? and what about this motor you need a much more complex controller http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14427
> best Regards,
> Jacob Rybalsky


 
Hi Jacob, my karts current config is KZ, but the chassis can be used interchangably with KF too. Ive havent run KF, but I did run its predecessor Formula A back in the day. Heres a (not so great) pic of my current kart. In this pic it has a modded YZ125 as opposed to a kart specific motor bolted on: 











I don't understand the point of DD2 to be honest, I figure just go the whole hog and run KZ or spec moto if thats a available in your area. I dont know why rotax didnt just pull from their Rotax 124 parts bin. The 124 was a rotary valve 125cc 6speed, akin to what KZ is today. Where are you based? UK?

If you plan running up front in Max or DD2 plan rebuilding 25hrs or so. That said in this case a "rebuild" is really just a top end refresh. If you think thats bad, in Formula A we would twist the motors up as high as 21K RPM, usually 40mins between top end refreshes, a bottom end every second top and a new rod every fourth bottom, sometimes second.

The thought of getting a class running locally certainly crossed my mind, and partly thats why im looking at peformance first. At least then I can take it to the track and explain the costs of extending the range at the expense of weight, and of course money! Seemingly the karts at Bercy are running cobalt batteries but that sounds a tad dangerous! 










http://www.sodikart.com/en/passion-bercy-erdf-masters-kart.html

115KG (250lbs) is a bit on the heavy side, but its a step in the right direction. No mention of price though.

KERs or regen isnt on the cards for me yet. As it is my goals are "ambitious" enough I think LOL

That motor you posted is intresting, not expensive either. Is it a PM though? I laughed a little when it said eqiv to 100cc then went on to say 20HP+. That better be a big plus! The more I look around the more I keep coming back to those Thundersky cells, they seem to be a good compromise and commonly used. I think if I go that route, I'll go with 60Ah as the $/Ah is a bit better.


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## major (Apr 4, 2008)

EVKarter said:


> http://www.sodikart.com/en/passion-bercy-erdf-masters-kart.html


Nice lookin' eKart  Factory engineered liquid cooled AC motor. I don't even object to PM there


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## EVKarter (Jun 22, 2011)

major said:


> Nice lookin' eKart  Factory engineered liquid cooled AC motor. I don't even object to PM there


LOL. What about the Cobalt Manganese batteries? Risky choice?


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## major (Apr 4, 2008)

EVKarter said:


> LOL. What about the Cobalt Manganese batteries? Risky choice?


These are Lithium batteries. LiPoly, I think. Maybe like the Kokams I used. Risky? I guess. All energy sources or storage devices have risk. Should they be used? Sure, why not? You just have to be smart about it 

In our 100 lap race, there were a lot of teams using Ener1 LiPoly. But the red flag incident was caused by a Thundersky (LiFePO4) venting. The "safe" type  Really no problem, just stinky and a 10 minute rest (delay) during the race  to clear the kart from the track. 

major


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## EVKarter (Jun 22, 2011)

DD2 is a spec series, but so is Max. That's what I dont get about it. For the extra expense of DD2 you get a little extra power, one extra gear and a weird-ass solid drive setup. IMO, if you are going rotax, skip DD2, but thats just my opinion.

As far as I know, theres plenty of KZ2 running up in canada, certainly more than in the US. Might not be in the region you are in maybe? KZ2 is same motors, medium tires and no pnumatic or electronic shifters. Otherwise they are identical. I was under the impression that KF2 was running up there too.

25hrs is a lot longer than you might think, if you add 25hrs of "hard running" is quite a while. I would hope you are at least changing valve springs often in the Honda.

FA got replaced because some idiot who knew very little about karting took over leadership of CIKFIA and decided a good idea to move karting forward was to take a kart, and pi$$ all over its design philosophy. He elected to make karts heavier, add more electronics add more variables and complexity to the motors and add an electric starter. Despite the extra power, KF1 is still a little slower slower than an FA and quite a bit slower than FSA. It was a dumb move to try and replicate Max and capitalize on it, but what the CIKFIA failed to understand was that market was already cornered by rotax. Revlimiting the 100cc motors would have made all the difference. Change the ignition, keep the rest simple and light rather than abandoning 30+years of simple but powerful 100cc motors and making them paperweights. It destroyed karting arguably more than the economic hardships of late....Anyway, I digress.

Aprillia's first RS125 ran a Roatx motor I believe, but its was nothing like the FR125 from what I understand. I could be wrong on that...

Anyway, got some tire testing coming up so I gotta get this thing running with a gasser for now


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