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Posted by: sgomes Aug 29 2004, 02:24 PM

Just a few progress pics for the curious. It's not a huge amount of progress but at least it feels like the project is starting to move forward!

This is a pic of the taper lock hub. It's the reason for my question about flywheel distance. I have about 5 cm of play here so I needed to know where the flywheel was SUPPOSED to end up. Thank you Demick for the fantastic data dump you gave me!

The amazing thing about taper lock hubs is that you can remove the bolts completely and the thing still won't come off!


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Posted by: sgomes Aug 29 2004, 02:25 PM

Flywheel: Demick -- the final distance was 44.2mm


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Posted by: Brad Roberts Aug 29 2004, 02:25 PM

Cool. So you can use a stock flywheel/pp/disc setup ?


B

Posted by: sgomes Aug 29 2004, 02:26 PM

Now THIS is how to spin up a motor on the bench!!!

(and you thought your STARTER motor sucked amps!!! )


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Posted by: Brad Roberts Aug 29 2004, 02:26 PM

Ha ha.. we both posted at the exact same time.. TWICE.


B

Posted by: sgomes Aug 29 2004, 02:27 PM

Brad, yep it's stock all the way. Ok, I didn't use the engine seal thingy since I don't have any oil in my motor!

Posted by: sgomes Aug 29 2004, 02:29 PM

Oh and just cuz... here is the P. Plate:

Posted by: sgomes Aug 29 2004, 02:29 PM

This time for sure..


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Posted by: Aaron Cox Aug 29 2004, 02:43 PM

wow!...

now what do u use as final drive ratio... just 5th gear?
whats the torque on that e motor?

Posted by: sgomes Aug 29 2004, 02:57 PM

Comparing gas engines to electric motors is always complicated. If I told you that this motor is rated at 20 Hp you'd say well gee that doesn't seem like enough. Problem is gas engines are rated at peak Hp whereas electric motors are rated at continuous Hp. The peak on this motor is rated at 90Hp but many people have run it 2 or 3 times that! Torque is even more complicated.

I'm using a stock 901 tranny so the final drive is stock. And mostly I just use third gear.

Basically I've put this system together to deliver something very close to a 1.7L 914. I'm just trying to make a daily driver not a rocket like Otmar's.

Posted by: Brando Aug 29 2004, 03:07 PM

is there any shifting with an electric motor car? I've always wondered... since when you let off the power, the engine stops spinning, wouldn't that make for grinding gears?

Posted by: sgomes Aug 29 2004, 03:12 PM

When you let off the pedal the motor doesn't stop. In fact it will keep spinning for a VERY long time. You just aren't ADDING any energy. Since there is no compression like a gas engine it will just spin forever. Actually thats a difference in how you drive an electric car correctly. You get it up to speed and then take your foot off the pedal. It feels like you have cruise control. When the car slows a bit you just give it a little pedal and repeat.

Oh and on the subject of shifting.... You don't have to use the clutch at stop lights since you can't stall! You don't HAVE to use the clutch to go again either (I do though.)

Posted by: Aaron Cox Aug 29 2004, 03:14 PM

good point.

electric motors develop most of their power and torque at low rpm's right?
so i thought you just start in whatevr gear youd like....and vary the current for more or less speed

Posted by: Brando Aug 29 2004, 03:23 PM

how do you engine-brake?

Posted by: Rhodes71/914 Aug 29 2004, 03:35 PM

That's very cool, an electric engine in a 914. My "alternative transportation brother would love it!

Posted by: sgomes Aug 29 2004, 03:54 PM

In MY setup I don't engine-brake at all. Yes that means the brakes get a work out. Hence my upgrading to 320i brakes on the front. Some people do put in regenerative braking to charge the batteries and that makes the car feel like it has tons of compression.

Sean:

send your brother this link: http://www.electroauto.com