Rear Hatch Release Popper

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Major System Category: Body (Hatch)
Task: Install hatch release popper
Parts:
Prerequisite Tasks: Assemble and mount hatch latch
Additional Costs: $42
Time Requirement: 2 hours
Date Started: September 14, 2012
Date Completed:  September 20, 2012

One goal I have for the car is to eliminate keys. It might even be possible to eliminate fobs and rely strictly on a smart phone, but I'm not quite sure I want to be that radical. To this end, how do I open and close the hatch?

45 lbs solenoid mounted to the edge of the body shell in a direct line to the hatch  latch.

The kit solution is a very long cable snaking from  the rear hatch to the cockpit that needs to be pulled and the hatch opens. By the time I looked at this, I was two months into the build and a certain skepticism was developing as to how things will hold up long term. I really don't like the cable idea. So I have moved on to a popper solution. I am also planning to go with door poppers as well. Two door and trunk popper kits are available on Ebay at reasonable prices.

Steel cable looped through the eye of the latch and back to the solenoid. I still have the red  zip tie attach. This my emergency release cable. I will need to replace this with a steel cable once I install the engine.

The popper is a simple device. It is a looped steel cable threaded through the eye of the latch release and connected to a solenoid. I have a 45 lbs solenoid for the trunk and 60 lbs for the doors (this is a measure of pull energy for the cable, not weight.) The popper solenoid is grounded. The power lead will be connected to an ISIS power cell and ultimately controlled by a touch screen control.

These clamps are holding the solenoid in place as the 8115 sets up overnight.

The cable between the latch release and the solenoid works best on a straight line basis. Certainly, a pulley can be added for angles, but this just becomes another point of failure. Since the latch is mounted to the body shell, I mounted the solenoid to the body shell, and this is where things get interesting. There really isn't a good place to do this. Absent an engine, transmission and exhaust, this area looks wide open - this is a mirage. The exhaust exits on both sides of the license plate and this sits right below the latch.

These are the electrical butt splices I used to clamp down the wire. It is a tight fit (which is fine), but you can get the steel cable through these connects twice.

My solution (for now) is to mount the popper solenoid on the body shell using 8115 adhesive (this stuff is incredible. I would like to reinforce this mount with some kind of strap. I did not like the little lead wire clamps. I figured if something got messed up and I had to take things apart, then I would need a replacement for these. I discovered that I could use a 10 gauge electrical butt splice and make everything work.

This is my little test battery. It weights about four lbs. I can duct tape it to the lift, and it is rechargeable.

I measured everything out, looped the cables and clamped the splice. Then I used my little 12 volt test battery to make sure everything works according to plan. These are great little sealed lead acid batteries for testing individual circuits. To test that everything works, I just touch the leads together and watch the solenoid fire. Great fun to see something actually work.

All done. The steel cables are clamped. I covered up the parts that could cut someone's hand with wire loom. I will see how well it stands up when I remove the body shell next summer.

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