[Duncan]

Help Required!

I have got a lovely big beefy reversing contactor - an Allbright SW202

However it has 36 volt solenoid coils - it takes 18 volt to pull in but it maintains down at 4 volts

Any suggestions about how I use this on my 12 volt system?

 

[Duncan]

What about using two of these? - one on each coil

They should each be good for 1.2 amps and I measure 0.4 amps from the solenoids

https://www.banggood.com/3pcs-3V5V1...-p-1328577.html?rmmds=search&cur_warehouse=CN

 

[MattsAwesomeStuff]

What about using two of these?

You can get 2587 boosters for a lot less than that. They should be around a bucks a piece, shipping included IIRC last time I ordered some. Ebay. Usually sold in 10-packs. Solder your own wires onto the board instead of using screw terminals if you want to save a few bucks. Cheap as chips but order extras because they take forever to get there and naturally you'll blow some up.

Handy little things.

I think they often claim they're good for 3 amps, but, in testing I seem to recall the solder melted and stuff started floating away north of 1.5-2amps.

For maintaining 0.4 amps, they'll be fine. Shouldn't even run warm.

 

[Duncan]

Hi Everybody

Finally back able to do something with my car

First Autocross since February 2018

Great fun
My son Thomas drove as well - his first time driving on grass - and it was gently raining

https://www.youtube.com/watch?v=iUigfkOv6DA

 

[Duncan]

Second Autocross
Forbes
And this time it stayed dry

We start off with a couple of pictures of us both in the car for the "indian file" to show us the route

Also took some Video

https://www.youtube.com/watch?v=jCGqaiAht88

Great fun

 

[Baratong]

Glad to see your Dubious Device is still going strong!

 

[dkubus]

Very very cool Device Duncan 👍👍

 

[Duncan]

Getting ready for the Annual Cobra Drags tomorrow

Removed passengers side head rest
Removed passengers side mirror
Fitted Passengers side Tonneau cover
leaving the road tyres on on the front
Sticky track tyres on the rear

Tyre pressures....

I will increase the front - normally 20 psi to 30 psi

The rear.....
I got a lot of extra grip last year at 14 psi
Maybe try 12 psi

 

[Evbeddy]

Hey Duncan

How did you get on at the drags yesterday?

 

[Duncan]

Successful day at the Drags

Improved from 7.90 seconds and 93 mph to 7.83 seconds and 96 mph

I beat all of the cars except for two of the T buckets - one just pipped me by 5 hundredths

But the other is a bit of a monster and di 6.50 seconds

It was hotter and I tried dropping the tyre pressure to 12 psi
Made a lot of difference!
I could not make the tyres spin for my "burnout"

You know what that means

I need MORE TORQUE!

I will ask Paul if I can boost my 1200 amps to 1400 amps

 

[drother]

The rear.....
I got a lot of extra grip last year at 14 psi
Maybe try 12 psi

What rear suspension and what tires? Are the rear shocks adjustable?

 

[brian_]

What rear suspension... ?

Duncan described the suspension (and his approach to suspension) in the first few posts of this thread. It is the McPherson strut setup from a Subaru Legacy, but I believe that he has the rear longitudinal links running rearward from the hub, instead of the stock forward, due to packaging constraints.

 

[Duncan]

Hi Guys

Successful day at the drags - then a very fun tarmac autotest

Only when I got there I remembered the video camera still plugged into the charger - bugger

Great fun on the day - much longer and faster than before so even with giving it a top-up we only had enough power for the Indian file - then two runs for me and three runs for Thomas

Neither of us posted any really good times and a number of cones were murdered

Great fun the car went like a demon!

At the end of the event it went on strike and refused to go into forwards
So we winched it onto the trailer

Back home it started working again - I think I wasn't getting enough juice from the auxiliary battery to pull in the solenoid
This thought came AFTER I had started charging the auxiliary so I wasn't able to check the voltage

Anyway I took the contactor to bits to have a look at the contacts

They are marked but feel quite smooth

Should I trim them up?
With what?

Or should I leave them alone?

 

[Duncan]

What rear suspension and what tires? Are the rear shocks adjustable?

Subaru - from a 1994 GT - 4.1:1 LSD

Adjustable rear struts with 125 lb/inch springs - set to full soft on the dampers

The forward facing rods going backwards

Tyres are NITTO 225/45/ZR 17 - recommended for competition use only on 17 inch x 7.5 inch rims

With me in it it has 55% of the weight (900 kg with me in it) on the back wheels
And I have corner jacked it to have the same weight on both rear tyres

 

[drother]

Subaru - from a 1994 GT - 4.1:1 LSD

Adjustable rear struts with 125 lb/inch springs - set to full soft on the dampers

The forward facing rods going backwards

Tyres are NITTO 225/45/ZR 17 - recommended for competition use only on 17 inch x 7.5 inch rims

With me in it it has 55% of the weight (900 kg with me in it) on the back wheels
And I have corner jacked it to have the same weight on both rear tyres

Do you have any slow motion videos of trying to launch while drag racing? Preferably from a 45 degree angle so both front and rear sides can be seen.

When you say full soft, is that compression, rebound, or does 1 knob control both?

 

[Duncan]

Do you have any slow motion videos of trying to launch while drag racing? Preferably from a 45 degree angle so both front and rear sides can be seen.

When you say full soft, is that compression, rebound, or does 1 knob control both?

One adjuster adjusts both - and no useable video

 

[major]

Hi Dunc,
I typically use emery cloth or even sandpaper, fine grit, for the contact buttons. Blow the dust out afterwards. Smooth to the touch and closing without any gaps should be good to go.
Regards,
major

 

[Duncan]

Hi Dunc,
I typically use emery cloth or even sandpaper, fine grit, for the contact buttons. Blow the dust out afterwards. Smooth to the touch and closing without any gaps should be good to go.
Regards,
major

Thanks Major

I was advised to avoid Silicon Carbide - so I used fine sandpaper
The contact areas all cleaned up nicely and it now seems to be working fine

I also connected up the old microswitches so I can now see if the contactor has moved

Just keep an eye on them

 

[Duncan]

It's electric - but not a car

The Local Steampunk group is holding "Teapot Races"

So the Cookie Monster and I converted Thomas's old tank into a teapot racer

We got the prize for the "Most Amusing" when four of the starboard road wheels fell off as it crossed the finish line

 

[zsnemeth]

Huge thumbs up!

It's electric - but not a car

The Local Steampunk group is holding "Teapot Races"

So the Cookie Monster and I converted Thomas's old tank into a teapot racer

We got the prize for the "Most Amusing" when four of the starboard road wheels fell off as it crossed the finish line