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Discussion Starter #1
Hi Guys,

I'm totally new to this, and have not gone through every post.

So I decided to ask, incase this has already been asked, please don't fry me.


I would like to convert me TA(Time Attack) Track Car to Electric.

Some facts:
I'll be replacing a Combustion engine that delivers over 650bhp.

What kind of RPM can I achieve ?
What kind of Power ?
Is Manual Transmission ok ?

If I can convert to a Electric system, that will give me equivalent or more Power. Please inform me.

& Let the design begin.
 

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Manual tranny is great. You can get motors that redline between about 5000 rpm and 13000 rpm. You can feasibly do 1000 hp if you get expensive batteries and run multiple motors and multiple controllers. 13000 rpm and 1000 hp are going to be very expensive.

http://www.PlasmaBoyRacing.com is John Wayland's site. He is running around 500 or 600 hp in an electric old drag racing Datsun. Here's another site you'll find fun: http://www.ProEV.com

Power is quite doable, but you also need enough energy to do the whole race. Time Attack is much longer than a drag race. Figure out how many minutes you need to run full power, and you can figure out how much batteries can dish out for that long.
Hi Guys,

I'm totally new to this, and have not gone through every post.

So I decided to ask, incase this has already been asked, please don't fry me.


I would like to convert me TA(Time Attack) Track Car to Electric.

Some facts:
I'll be replacing a Combustion engine that delivers over 650bhp.

What kind of RPM can I achieve ?
What kind of Power ?
Is Manual Transmission ok ?

If I can convert to a Electric system, that will give me equivalent or more Power. Please inform me.

& Let the design begin.
 

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Joined
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4 Posts
Discussion Starter #3
Hi

Thanks for the good news !!

Most circuits are under 2 min !!
and I may need to do 3 - 4 laps - so lets say 8 min.

but not at full power !!

1000bhp - wow

Hook me up:-

What do I need ... I'm happy with 600 bhp
As the car will be much lighter, and I can distribute the weight as needed, to get perfect balance.

This is very good news !!

Please tell me what to buy - I have a budget of 20K

Is that enough ?
 

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Unfortunately $20k is not enough.

Let's start with batteries. Let's say you need to do 4 minutes of max power. A123 batteries are the best, but very expensive, so let's do Headway batteries.

Specs for a headway battery:
8 Ahr
200 A continuous max
0.004 ohms internal resistance
~3.3 Volts nominal

Max current for 4 minutes would be:
8 A hr * (60 minutes / 4 minutes) = 120 A
You'd want to back off that a bit, so let's say 100 A to make it easy (you probably should back off more than that).

Power for 1 cell = (3.3 V - 100 A * 0.004 ohm)*100A = 290 Watts

650 rwhp ~= 650 kW at the batteries

650 kW / 0.29 kW = ~2240 batteries

2240 * $13 = $30k

So there's $30k just on batteries, plus that pack would weigh ~700 kg.

Suppose you can get hard running time down to about 2 minutes (take it easy lap one, hit it hard lap 2, and take it easy lap 3).

Now you are running the batteries at 200 A, and about 80% capacity.

Power for 1 cell at 200A = 500W

650 kW / 0.5 kW = 1300 batteries

1300 * $13 = $17k
Plus you'd need twin motors and controllers, for another ~$16k
(Plus a charger, wiring, adapter, etc.)

If you could be happy with about 1/2 that power (that's still a very powerful car) and just 2 minutes of high power, then you might get away with just one big motor and one controller, and 1/2 the battery cost. Now you might make it for ~$20k.

Big message is the smaller and lighter your car, the less it is going to cost to get to a particular power/weight ratio. That's one reason I'm doing a Porsche rather than a muscle car.

CroEV has a great car on this board, more than $20k but along the lines of what you are thinking about.

Hi

Thanks for the good news !!

Most circuits are under 2 min !!
and I may need to do 3 - 4 laps - so lets say 8 min.

but not at full power !!

1000bhp - wow

Hook me up:-

What do I need ... I'm happy with 600 bhp
As the car will be much lighter, and I can distribute the weight as needed, to get perfect balance.

This is very good news !!

Please tell me what to buy - I have a budget of 20K

Is that enough ?
 

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Discussion Starter #5
^^^ Thx for the info, I just read the sticky in the EV build section, so I guess I went about starting this the wrong way ... sorry for that..


I had a quick Look at CroDriver - the 600 bhp Green BWM - very nice.

Pretty much Exactly What I want to Build ...


My Car is not a muscle car, it would be almost equiv to your porsche ...

the car is currently well under 1000Kg ... but yes, putting a
Engine, Intercooler, Radiator, Exhaust, Starter, Fluids, PS Pump, bla bla bla -

will bring me up to ~ 1100 Kg..

The whole idea here is to have a TA Car that is :-

a) lighter than the rest with the same chassis
b) has similar Power
c) But can deliver Torque where I need it !!! - thats the big one ...!

Turbo Lag is my enemy - and a big problem.

If you know a MOD, can you have this thread moved .....

Cheers ...
 

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Can some one post the rules for the REDLINE TIME ATTACKS, I can't seem to get them even under search . This is what electric cars need to go forward . What about the SCCA and NASA ? do they have classes ?
 

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Hi Rpece,

Look at what the Sprint and hill-climb guys are doing - like Time Attack but with no room for mistakes!

Lightweight 150Hp cars normally walk all over the 600Hp+ heavyweights
 
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