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  #31  
Old 07-04-2012, 03:50 PM
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Default Re: Jordy's UK EV Racer

Quote:
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!
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  #32  
Old 07-04-2012, 03:58 PM
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Default Re: Jordy's UK EV Racer

Quote:
Originally Posted by Yabert View Post
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!
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?
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  #33  
Old 07-04-2012, 04:26 PM
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Default Re: Jordy's UK EV Racer

Quote:
Originally Posted by Jordysport View Post
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?
30 kilos difference is a significant percentage of your total weight (plus the additional cells needed to accelerate the extra mass). The larger motor also has greater rotational inertia, so won't spool up as fast. Admittedly they're small factors, but with a car as light as a Jedi I'd personally take a minimalist approach. It's a tough call though.
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  #34  
Old 07-04-2012, 04:43 PM
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Default Re: Jordy's UK EV Racer

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Originally Posted by MalcolmB View Post
30 kilos difference is a significant percentage of your total weight (plus the additional cells needed to accelerate the extra mass). The larger motor also has greater rotational inertia, so won't spool up as fast. Admittedly they're small factors, but with a car as light as a Jedi I'd personally take a minimalist approach. It's a tough call though.
Yes, it is 30kg but i may have future plans for a higher top end, 200mph is not that far out of the equation but thats a fair way down the line. at the end of the day the same principal applies to the driver if i loose 10kg from 70kg to 60kg thats a significant proportion of the total weight. Tis a tough call, will finish the Solidworks model and go from there..
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  #35  
Old 07-04-2012, 08:59 PM
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Default Re: Jordy's UK EV Racer

What is your distance from front to rear in the engine bay? Could you put a Porsche mid engine or Air Cooled VW transmission behind the motor with a longitudinal motor setup? It would put a lot of the transmission behind the axles.
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  #36  
Old 07-05-2012, 04:19 AM
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Default Re: Jordy's UK EV Racer

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Originally Posted by Batterypoweredtoad View Post
What is your distance from front to rear in the engine bay? Could you put a Porsche mid engine or Air Cooled VW transmission behind the motor with a longitudinal motor setup? It would put a lot of the transmission behind the axles.
729mm, but i've got to fit my cells in there aswell, the only other option i could do is buy a Formula ford, and use that as a basis as that has a Hewland 4 speed box, but I would have the same issues of space for cells.
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  #37  
Old 07-05-2012, 04:27 AM
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Default Re: Jordy's UK EV Racer

This motor would be ideal if you have deep pockets: http://www.yasamotors.com/technology/products/yasa-400

...and it's made in the UK
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  #38  
Old 07-05-2012, 06:36 AM
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Default Re: Jordy's UK EV Racer

Sure! If you have the money, don't bother with DC motor. A dual Yasa-750 is the way to go!

http://www.yasamotors.com/technology/products/yasa-750

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  #39  
Old 07-05-2012, 06:51 AM
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Default Re: Jordy's UK EV Racer

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Originally Posted by Yabert View Post
Sure! If you have the money, don't bother with DC motor. A dual Yasa-750 is the way to go!

http://www.yasamotors.com/technology/products/yasa-750

I can't really afford £100,000 on Motors
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  #40  
Old 07-05-2012, 12:42 PM
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Default Re: Jordy's UK EV Racer

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.
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