DIY Electric Car Forums banner

Jordy's UK EV Racer

40K views 114 replies 14 participants last post by  DIYguy 
#1 ·
Hi Guys been a long long time since i've been on here, a bit of an update i've now Graduated as a Motorsport Engineer and i have been looking at taking one of my race cars i have kicking about the workshop and develop it into an EV racer. and finally i have secured funding to do so.

Here in the UK we have a motorsport series called Hillclimbing, on average 1-2 miles of tight twisty's commonly uphill all on tarmac. most of the time the climbs are circa 40 seconds some upto 2 mins so range is not an issue...ideal you say for EV's. the car is a Jedi Single seater with minimal aero on it, in comparison to a formula ford 0.8m^2 (CdA) and a Jordan 191 F1 car 1.1m^2 (CdA) one with alot more aero and one alot less, and the formula ford being similar size I can assume a CdA of circa 0.9-1.0 (as i cannot do any coast down tests atm).

Some Specifications on the vehicle:

Vehicle Weight with Yamaha YZF1000 engine + Driver - 270kg
Vehicle Weight Enginless - 120kg

Now the replacement needs to be just as quick if not quicker, so the current engine produces 130Kw with fairly linear delivery: http://www.dynobike.com/images/graphs/r1_cbr1000_2.jpg

And on average 50lbsft of torque.

Now the main question:

Motors.......I am limited to an 11" diameter MAX as thats all that will fit in the chassis and battery space is limited but the side pods can be used.

What sort of motor would be required to achieve this performance, I can do all the calcs its just its not very accurate using Peak and Rated power and torque figures. if at all possible i would like to use a local company that produce these PM motors:

http://www.lmcltd.net/uploads/files/data sheet for LMC Motors.pdf

and if i used the 2x2 (2motors) in a small package of 25cm cubed producing 72kW , 84Nm Power at 72V which is pokey enough but will it be enough.

Thanks
Jordy
 
See less See more
#3 ·
I haven't been on a dynometer yet but I am very pleased with the torque I can get out of my WarP11 I've been running my car for a few years now. I drive it to work every day. It is all about the batteries, to that end I would look into a High Voltage WarP11. I have just started a dealership for Netgain motors and I have a brand new one in the box ready to send to you.
she feels way better that the 300 ft-lbs I had as a gas burner

https://youtube.com/ddmcse
 
#5 ·
I haven't been on a dynometer yet but I am very pleased with the torque I can get out of my WarP11 I've been running my car for a few years now. I drive it to work every day. It is all about the batteries, to that end I would look into a High Voltage WarP11. I have just started a dealership for Netgain motors and I have a brand new one in the box ready to send to you.
she feels way better that the 300 ft-lbs I had as a gas burner

https://youtube.com/ddmcse
Well i am looking at some High Power Headway 38120 8ah cells upto 10C cont. I am just struggling to find a V , A , & Motor Combo to give the performance required.

0-60 circa 3.5-4 seconds
Top speed More the better but must be over 100mph
Obviously this is in a chassis that will weigh less than 500kg converted, it weighs 240kg with driver atm.
 
#8 ·
Back of an envelope calculation says you need a motor that produces around 200 ft lbs (270 Nm) up to 3000 rpm to meet your acceleration target. With a 3:1 reduction that would take you to 100 mph at around 4500 rpm. The Lemco motors won't do it, and the Warp 11 sounds like overkill to me (as well as being heavy). Since each run is no more than a couple of minutes you could run a smaller motor at high amps...
 
#11 ·
Hi Jordy
It looks like the newer, upgraded Warp 9 motor might fit your needs IF you're comfortable with pushing it close to the limits. It should produce around 200 ftlbs of torque at 1000A, but obviously not for very long. I'd suggest getting advice from someone who has experience of running these motors close to the edge.
 
#19 ·
Hi Guys got some pictures on the way of one of my chassis's, but I will be having a new chassis made so it can be customized to my specs.



Hi Malc,

Looking at the Warp9 Vs Kostov after having a good look at my chassis i have about 14" of length from sprocket to edge of the chassis (1/2 inch of overhang) which makes the stumpy 14" kostov ideal. & with overhang in the open air with the fan on the end should give some nice cooling.

Hi, Nice Project :D

Being in the UK it'd make sense to plan to use parts available from within
the EU.
The kostov 9" motors are apparently very good and rated for higher voltage when compared to the warp motors. I dont really see the need to go 11" as most of the power needed in hill climbing is for a very short period.
Headway batteries as already mentioned as they can push out 10C+, again you dont need the range so these make sense. Go for the highest voltage your controller will accept. Eclipse bikes is a UK supplier.
http://eclipsebikes.com/lifepo4-bat....html?osCsid=23466c98d765ef5e05221596a16062cf

As for a controller, I really reccomend Evnetics controllers. They will go higher voltage than most so you can have the same power output for less battery amps. There not the cheapest but by far the best quality. Nothing but good words for them. I bourght mine from rebbl (below)
http://www.rebbl.nl/

I honestly think a kostov 9, Soliton Jr (yes only 600A but goes up to 350V) and a decent size headway pack (say 95s5p of 10AH) will make that thing fly!
Looking forward to this one :)
Cheers
Mike
Hi Mike,

I Don't have an issue with international purchases as i have contacts so thats no big issue i would prefer to get the top compnents rather than be restricted by delivery & locations.

As for the 11" compared with the 9 Inch an 11 inch will fit in there nicely with the top chassis rail being raised slightly in that area by 2.5 inches but again i am not worried about that.

The plan is to have it transversly mounted with chain drive (geared) direct to the mini diff. so i have a range of sprockets i can use (10-15 front) & (34-40 rear)

And what i like about the Kostov motor is the rpm limit of 6800 rpm makes it a bit easier with direct drive No?

Yes Hillclimbing is very short, 40seconds generally for a 1000cc Jedi, but remember its very unlikley you will be on full throttle for very long, Lookup Wiscombe Hill climb, there are only two places you will be on full throttle for more than 5 seconds.

Headway cells.... thoughts on these??? are they "deadways"? bang for buck they seem pretty good. and re supplier i can get good discount going direct.

Kostov 9" & 300V & 600A (Soliton Jr) would be good, the question is would it be less strain on the components than say 220V & 1000A but still produce the same "Umph"

I second what Mike said with the possible suggestion of using one of the more volatile Lithium chemistry batteries. They have higher power per weight but sacrifice range and cycle life.

I would ask Tessarect first, but cooling the Soliton Jr with an ice reservoir loop might be perfect for your situation to keep the 660 amps all the way up the hill.

Just curious: are you planning on using a transmission? All the calculations change if you are not.
The Cylindrical Cells is deffo the way forward for me with limited space and various combinations of arrangements of cells makes it highly advantageous along with the High C ratings.

Re cooling i can have a mini rad & water cooling for it no probs, I was planning on putting the controller under the seat with a rad against the side of the chassis with a cut out & obviously the rad angled slightly to get the air flow.

Direct Drive with gear reduction.

Jordy mentioned a Sierra diff, so I'm assuming no gearbox. The Jedi normally has a motorcycle engine/gearbox and chain drive diff.

The Soliton Jr/Kostov 9 combo would certainly give sprightly performance in a car as light as this, but with a single ratio I doubt it will meet both the acceleration and top speed requirements. I suggested the Warp 9 because it's known to handle higher currents. I think Plamenator said the Kostov 10 was designed as a direct competitor to the Warp 9; they weigh about the same, but the Kostov has interpoles for higher voltage, which make it slightly chunkier.
ah if its direct to diff then that changes everything!

Perhaps he could use a small lightweigh gearbox to get the right ratios? should add no more than 30KG?
No a gearbox is not possible in the space,

The packaging looks interesting to say the least.

Yes its compact, see my pics of my chassis with nothing in (ignore the central bars their just engine mounts which wont be there on the new chassis.

With high performance/short time application and direct drive in mind, I would suggest:

Kostov Alpha + 1000 to 1400A controller + 90S 2P (16Ah) of headway 38120HP

Motor and controller will give masive torque (380-500 Nm) and don't suffer that much for a minute race and the 60 Kg of battery will give a good power (90-110 Kw).

A123 AMP20 or Turnigy Nano-Tech can also be a very good battery choice (simply more complex to assemble).
Kostov Alpha is an 11" motor but thats not a problem as mentioned above, the question is.. is it sufficiently better than the 9" to warrent the minor chassis mods. and yes that sort of power would be very nice.



 
#12 ·
Hi, Nice Project :D

Being in the UK it'd make sense to plan to use parts available from within
the EU.

The kostov 9" motors are apparently very good and rated for higher voltage when compared to the warp motors. I dont really see the need to go 11" as most of the power needed in hill climbing is for a very short period.

Headway batteries as already mentioned as they can push out 10C+, again you dont need the range so these make sense. Go for the highest voltage your controller will accept. Eclipse bikes is a UK supplier.
http://eclipsebikes.com/lifepo4-bat....html?osCsid=23466c98d765ef5e05221596a16062cf

As for a controller, I really reccomend Evnetics controllers. They will go higher voltage than most so you can have the same power output for less battery amps. There not the cheapest but by far the best quality. Nothing but good words for them. I bourght mine from rebbl (below)
http://www.rebbl.nl/

I honestly think a kostov 9, Soliton Jr (yes only 600A but goes up to 350V) and a decent size headway pack (say 95s5p of 10AH) will make that thing fly!

Looking forward to this one :)

Cheers

Mike
 
#13 ·
I second what Mike said with the possible suggestion of using one of the more volatile Lithium chemistry batteries. They have higher power per weight but sacrifice range and cycle life.

I would ask Tessarect first, but cooling the Soliton Jr with an ice reservoir loop might be perfect for your situation to keep the 660 amps all the way up the hill.

Just curious: are you planning on using a transmission? All the calculations change if you are not.
 
#14 ·
Jordy mentioned a Sierra diff, so I'm assuming no gearbox. The Jedi normally has a motorcycle engine/gearbox and chain drive diff.

The Soliton Jr/Kostov 9 combo would certainly give sprightly performance in a car as light as this, but with a single ratio I doubt it will meet both the acceleration and top speed requirements. I suggested the Warp 9 because it's known to handle higher currents. I think Plamenator said the Kostov 10 was designed as a direct competitor to the Warp 9; they weigh about the same, but the Kostov has interpoles for higher voltage, which make it slightly chunkier.
 
#15 ·
Jordy mentioned a Sierra diff, so I'm assuming no gearbox. The Jedi normally has a motorcycle engine/gearbox and chain drive diff.

The Soliton Jr/Kostov 9 combo would certainly give sprightly performance in a car as light as this, but with a single ratio I doubt it will meet both the acceleration and top speed requirements. I suggested the Warp 9 because it's known to handle higher currents. I think Plamenator said the Kostov 10 was designed as a direct competitor to the Warp 9; they weigh about the same, but the Kostov has interpoles for higher voltage, which make it slightly chunkier.
ah if its direct to diff then that changes everything!

Perhaps he could use a small lightweigh gearbox to get the right ratios? should add no more than 30KG?
 
#17 ·
With high performance/short time application and direct drive in mind, I would suggest:

Kostov Alpha + 1000 to 1400A controller + 90S 2P (16Ah) of headway 38120HP

Motor and controller will give masive torque (380-500 Nm) and don't suffer that much for a minute race and the 60 Kg of battery will give a good power (90-110 Kw).

A123 AMP20 or Turnigy Nano-Tech can also be a very good battery choice (simply more complex to assemble).
 
#20 ·
The Evnetics controllers will hapily convert volts to amps but not the other way around - So higher voltage is typicaly better..

Kostov 9" & 300V & 600A (Soliton Jr) would be good, the question is would it be less strain on the components than say 220V & 1000A but still produce the same "Umph"
Power is power, the difference between the two is how much torque is applied. 600A should be about 150ft lbs (from 0RPM dont forget!) I dont think you could actually put the power down if you went higher, my RX8 with a Soliton Jr has problems putting the power down if I floor it.

I think 600Amps will provide oozles of torque for your application. going higher voltage means you can get the RPMs all the way up to the Kostovs limit. 340ish volts on the proposed headway pack may sag by a third at full current, so you still have all the volts you need for the motor.

yabert has an excellent smart conversion using headway cells.



Is there any way at all you could get some form of transmission/gearing in there?

What do you think about the variator idea? too weak?
 
#22 ·
The Evnetics controllers will hapily convert volts to amps but not the other way around - So higher voltage is typicaly better..



Power is power, the difference between the two is how much torque is applied. 600A should be about 150ft lbs (from 0RPM dont forget!) I dont think you could actually put the power down if you went higher, my RX8 with a Soliton Jr has problems putting the power down if I floor it.

I think 600Amps will provide oozles of torque for your application. going higher voltage means you can get the RPMs all the way up to the Kostovs limit. 340ish volts on the proposed headway pack may sag by a third at full current, so you still have all the volts you need for the motor.

yabert has an excellent smart conversion using headway cells.



Is there any way at all you could get some form of transmission/gearing in there?

What do you think about the variator idea? too weak?
Yes there will be gearing it won't be bolted straight to the driveshaft, theres going to be approximatly 14/34 ratio so approx 2.4 Min upto about 3/4 so i can vary the top speed according to the hill climb

a gear ratio of 2.4 at 6800rpm gives a (theoretical (power dependent) top speed) of 170mph and at 3.5 gr at 6800rpm gives 116mph so i should have a variation of 90mph-170mph top speed gearing. but if i used the 11" at 5800rpm limit. comes down to 75mph-150mph which is pretty reasonable.

At the end of the day surely the car is sooo light and with it geared down, it shouldn't be an issue.

Re-traction issues, you have to remember i am running ultra sticky slicks 14" wide at the rear, there nothing like road tyres.

At 340V it gives 316V after sag, it is alot 105s4p (32ah) or could i go less on Ah maybe 105s2p (16Ah) bit better at 210 cells, i am sure i could fit alot more cells in though.

Am modellng the chassis tonight, once the new solidworks has downloaded on my home pc. so should give a better idea of the setup i am looking at.

Cheers
Jordy
 
#24 ·
How would i fit them in the chassis, the thing is i can fit one transverse via chain to sprocket due to the fact the diff & sprocket is offset in the chassis its not central. plus lookup Sawbench corner at wiscombe, its a massive harpin, and it won't be a LSD it would be a welded diff effectivly and it would spin up the rears.
 
#29 ·
Yeah thats what i thought you meant,

I think for simplicity to start with a single motor would be good, after which if i need more i can always go down that route. Looks like a 11" Alpha will fit in there so i am thinking down that route, with soliton1. headway cells (430mm (L) x 420mm (W) x 240mm (H) est 180cells and space along side the motor of (300mm (L) x 140mm (W) x 240mm (H) est 96 cells which would nicely give 95s3p but i could get another 100 cells above the chassis rails upto the engine cover, to up it to 95s4p to allow full 1000A on the controller.
 
#30 ·
This is one of the best threads i've ever read on this forum!! Some great minds offering great suggestions for the greater good.

I'm going to be watching how this monster develops very closely.

So pleased to see this all going on in the UK! Awesome, well done.

Adam
 
#31 ·
Originally Posted by Jordysport
Kostov Alpha is an 11" motor but thats not a problem as mentioned above, the question is.. is it sufficiently better than the 9" to warrent the minor chassis mods. and yes that sort of power would be very nice.
Please notice the difference betweem 11'' and 9'' motor:

Kostov Alpha 11: 75Kg, 270mm dia.
Warp 11: 105Kg, 290mm dia.

Kostov 9: 45Kg, 231mm dia.
Warp 9: 70Kg, 235mm dia.

Personnaly, I think that an extrem torque is way more important in direct drive application because you can't shift a gear to have peak power most of the time.
Of course, that also depend of your speed variation during the race. If the motor speed is always around peak power during the race that can be different than if you need 120 mph in a stretch and 30 mph in the next curve!
 
#32 ·
I Don't think you quite get the application, its not a "Race" that denotes Circuit racing which it is not.

Hillclimbing is an A-B short sprint which is very technical, put into youtube Scott moran doune, will give you an idea of how we roll here. There is so much variation in top speed, high speed corners and very low speed corners, On that logic maximum torque possible would be advantageous to maximise acc low down along with the high voltage to achieve a high (120+) terminal velocity.

The biggest issue in the chassis is the motor length (no punn intended) but the kostov is nice and small at 14" compared with warp motors and the difference in legnth between the Kostov9" and Kostov11" is negligiable thus why not go for the bigger motor for greater flexibility in the future for upgrade?
 
#40 ·
Ok guys, Update time my head has been going round in circles today but come back on the Jedi glad i have as its covered nearly all possibilities. I am having trouble having validating my calcs, say the following specs

CDA- 0.65
Rho - 1.176
304 V
1000A
Kostov9" Motor (Max RPM 6800)
Soliton 1 Controller
Headway 38120HP (95s5p)
Total Weight Inc Driver - 450kg
Gear Ratio 2:1

From the Kostov 9" Motor graph at 1000A produces 380Nm of torque with a tyre diameter 0.507m which gives a driving force of circa 3000N and using F=mu *R to find if its traction limited gives well over 5000N with slicks but with narrrow road tyres gives circa 3000N. Now my calcs haven't acounted for RR but relative to Aero drag it would have a neglible affect.

Question is Guesstimate the top speed. as i am getting some very fast figures (near 200mph and 0-180mph in 19 seconds (assuming perfect traction)

But with WOT at any rpm will the motor produce peak torque? looking at the graphs they will not, so I presume my calcs are all wrong. but see it difficult to input the motor data into a spreadsheet to calculate it.
 
#42 ·
But with WOT at any rpm will the motor produce peak torque?
No, like I told you. You get peak torque (at current limit) only up to base speed (RPM). That base RPM is voltage dependent. And that voltage must include any sag and voltage drop. So just a guess.....at that point, your base RPM will be in the range of 2500/3000 RPM for the 220 volt curve.

What is your mph/RPM ratio? I typically use "XXXmph/1000RPM".

Also, what do your calcs say the voltage is at 1000A? And have you inquired as to the motor survivability at 1000A for 20 seconds?

major
 
#41 ·
It would be nice if it was that simple :) Your calculations look good, but like you suspected, you won't get max torque all the way up to maximum rpm. The Kostov 9 may be able to take 1000 amps for seconds at lower volts, but I doubt it could cope with 1000A at 220V. Back EMF from the motor also means that torque starts dropping off before you get to maximum rpm. I'd suggest getting in touch with Kostov and asking what they recommend. One of their engineers is a member here and is very helpful. His user name is Plamenator.
 
#43 ·
Hi Malc, Yes as i expected, the best way probably to estimate it is to model the Motor graphs in excel that way i will get a much better value for top speed and Acc.

Thats a good idea, will contact him today.

Just an idea, with direct drive & long gearing requiring ideally higher rpm, would AC be a better option?

No, like I told you. You get peak torque (at current limit) only up to base speed (RPM). That base RPM is voltage dependent. And that voltage must include any sag and voltage drop. So just a guess.....at that point, your base RPM will be in the range of 2500/3000 RPM for the 220 volt curve.

What is your mph/RPM ratio? I typically use "XXXmph/1000RPM".

Also, what do your calcs say the voltage is at 1000A? And have you inquired as to the motor survivability at 1000A for 20 seconds?

major
Hi Major,

Unfortunatly i did have trouble understanding at first, linguals and forums aren't ideal for expressing engineering topics. But I fully understand now, so thank you for your patience.

30mph/1000RPM , looking at the motor graph at 1000RPM it will be wanting the full 1000A at which point it begins to tail off. 0-30 mph will be done at full 1000A. Is my logic correct.

well at 1000A , V = I*R . internal resistance of the cells is 0.04 Ohms so 0.04 *1000 = 40V so 304-40 = 264V which would appear to be too high listening to most peoples estimations. but in my spreadsheet this has no affect on the calcs (only number of cells) as i take the torque value straight from the motor graph. (need to create a motor Map to get a proper estimation)

Many Thanks

Jordy
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top