Aussie EV Autocross Special

Sure thing. I'll need to take a couple first. I am fairly happy with the left side but the right side is a dog's breakfast. I also did the repair on my brakes but I got the angle wrong so I will have to pull it out again next weekend and redo it.
 
The first photo shows how I aligned the front wheels at almost their maximum turn to make sure the three chords (two front wheels and rear axle) intersect at the same point.

The result was I needed to bring the Tie rod end in by 12mm on both sides. The second photo shows where I cut the hub sandwiched the gap with two plates (above and below). Bolted it all together. Wedged some steel in the gap to minimise any movement and to ensure not all the force is on the bolts. Then welded the wedges to the plates to ensure they don't slip out, twist or move.
 
I am not happy with the amount of meat left on the tie rod end side. I think this week I will rummage through my parts stash and look for some more hubs. I will cut the steering knuckle off the spare hubs. But this time I will cut them 12mm longer. This will eliminate the need for the wedge and also give me more meat to hold the bolts on the steering knuckle. I think I will be much more comfortable with that in place.
 
The doner is a N13 pulsar.

Yes I thought about using hubs from another model like Nissan EXA or NS/NSR. But according to interweb they have the same wheelbase as a pulsar so the ackerman angle / steering knuckles would be the same (no benefit).

I also thought about using hubs from a totally different car. The hubs would need the same bolt configuration for the strut, the same bolt configuration for the wheel and be from a car with an extremely short wheelbase (like a Smartcar). I suspect my bigest challenge with that sort of replacement will be the size of the front brakes as every car I can think of with such a short wheelbase is a lightweight car and wouldn't have descent brakes.

I do have a spare set of pulsar hubs so I think this is still my best option. Although using my spares introduces a risk if something goes pear shaped. But now I have had one attempt I have increased confidence I can get it right second time around.
Redoing them will mean a fair bit of rework, cutting the steering knuckles, making 4 new plates, drilling all to suit. But I think the finished product will be well worth the time and effort. I think with a bit more meat around the bolts I will feel at ease about the structural integrity.

I will post more photos of the results this weekend.
 
Bugger

It sounds like you do a fair bit of braking do you run a vacuum pump?

When you destroy that DC motor get a AC 50 and have ReGen :D

Cheers Kiwi
 
Ba ha ha ha yeah I need good brakes. No booster though, I ran out of space. The first 80% of the pedal was great and quite effective but after that the bar was just bending rather than increasing the stopping power. But I am confident my planned adjustment will get it working correctly.

Destroy the Dc? Hell I think I'm only using 30% of it's capacity. Not much chance of destroying it. If I ever want to destroy it I'll start tesing how much I can tow with it. Now lets see put my 240z on the car trailer, attach my bt50 to that and lastly attach my 280zx. That should be a fair test. I thought about swapping the bt50 and 280zx but putting the 280zx between the bt50 and car trailer would likely rip it in half.
 
:lol: :lol: :lol:

They will destroy I did to much high revs and that was with twin blowers thats why I went AC

I have had the Sonic on a back road sitting on 175kph 7000rpm for 10 km my old warp 9 would never had done that.

Cheers KiWi
 
This weekend I redid the weld on my brake pedal and redid ackerman angle modification.
I haven't got a photo of the finished product but you can see from these photos the old steering knuckle on top and the new one underneath.
The new one successfully eliminates the need for a wedge and gave me pleanty of space for the bolts and pleanty of material around the bolt holes.
I gave them a bit of a test in the afternoon and put them under as much stress as I could. No sign of any problems.
I now feel confident enough for the next event. But before then I will still swap my original flywheel with the light weight one. I also want to install a second volt meter for the auxilliary battery so I have some warning before my contactor cuts out on me.



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Looks good Greg

If you can get them down to Ipswitch I can get get one of my boys to crack test them for free just PM

Btw looks like we have the same puppies :D

Cheers Kiwi
 
damn it ,

i only found out about this today , would have loved to see this in action in rocky
 
evrob said:
damn it ,

i only found out about this today , would have loved to see this in action in rocky

Me too. 5 runs can hardly be considered action. I think my disappointment is leaking through into this post.

But there is always next year. And by then I should really have ironed the bugs out and have it up the competitive end.

Next event is the Khanacross May 22nd at Willowbank. I have fixed the brakes, fixed the ackerman angle (I hope). This weekend I will swap my lighten flywheel in.
So fingers crossed, I am aiming for my first complete event and most successful result in this car to date.

The event after that is a Motorkhana on Aug 7th at Willowbank.

I am also coming up to Proserpine in September for the Australian Khanacross championship. But for that I will be competing in a Subaru AWD turbo.
 
I have now swapped in the lightened flywheel. That took a few attempts / false starts before I managed to align it correctly.
I also added the Voltmeter for my aux battery.
Took it all for a test drive. Seems good to go. The flywheel is quite smooth. Its about on par with the heavy one (which was also surprisingly smooth).
Now I just need to spend the next week charging my batteries (and resisting the urge to use up the charge on more "testing")
I am quietly confident Sunday should be the car's best showing to date. But I don't expect it to be the fastest out there. Not until I solve the battery dramas. I am assuming it will still top out at around 90Kmph. But if I get more it will be a bonus.

Aside from the charging the only other things I need to do in preparation are Vacuum out the crud, wipe down the outside, put in the upper half of my harness.

Bring on Sunday!!!!
 
Can someone tell me if I am missing something?

My controller has a current limit setting. There is no way to quantify what it is set to. I can only measure the current.

With my original AGM batteries I was getting very good launch but at the time I had no way to measure the current. The maximum voltage was around 155V.

I then changed to the lithium Ion pack from a Chev Volt. My maximum voltage is now 170V. I can now measure my current and it peaks at around 220Amps. But the launch is not as good as it was with the AGM batteries.

Because I only changed the batteries I assumed they were the limiting factor. From this assumption I also figured there was no point playing with the controller current limit because the batteries would still hit the same maximum output.

But I guess I should see if anyone else has thoughts on the issue?
Could it be more about the way the batteries deliver the power (discharge curve)?
Could it somehow be the combination of batteries and the current limit in the controller?

I think I will try and increase the current setting on the controller and see if I magically get more acceleration. Even if it only gives me a few amps it might make all the difference, particularly in the higher gears where I need it most.
 
I think its the batteries also what was the temperature when you used the lead batteries and now with the volt pack I bet it was cooler now. Also I find that the pack works better around 20 to 25 temperature that is the actual cell not air temp.

Just out of interest what is the Ah rating of the lead cells verse the Volt cells?

Cheers Kiwi
 
I have no way to measure the cell temp. But there has not been any significant rise in temperature detectable by hand.

The Lead Acids were 14ah. The Volt pack are 40ah
 
The next instalment has been and gone with a Khanacross yesterday.

• The weekend started with a question mark after I accidentally blew another volt meter (that makes 3 so far).
• I was competitor 1 which does not provide an opportunity to observe other competitors and gain a point of reference. But that is the luck of the draw.
• Then the event on Sunday also had a few false starts.
• In the second run the car stopping entirely. But this turned out to be a good thing as it prompted me to discover a loose connection that I am convinced was causing the intermittent pauses as well as a likely reduction in current/torque over the past few months.
• After resolving that issue the rest of the day was excellent. My times were respectable but not quite competitive yet, I can certainly see the light at the end of the tunnel.
• The second last video shows a bit of a save at the 1:24
• The last video is one of my faster runs of the day.

The main things moving forward are:
• Learning to trust the car a little more. In particular the handling and braking
• Getting more current to the motor.
• Softening the front suspension a touch
• Design and implement a launch control system to limit wheel spin off the line.
 
As you can see I have included some different angles. They didn't work quite as planed. My helmet tended to push the angle down a bit too far. I'll try something different next time.

Oh and the driver in that last video is not me.
 
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