Thinking about drilling a 3/4 inch hole through the firewall to an Accusump on the other side. The Accusump will sit facing backwards towards the cockpit firewall mounted where the seat normally goes.

Anyone ever drilled through this section.

There is a black arrow where I want the hole.

All advice appreciated.

Click to view attachment

BTW I'm going to cover up that higher hole where the lines used to run to the front cooler.

You can put a bulkhead fitting through the pocket there.
That's the only location on the lower firewall where the two panels have no empty space between them.

What Chris said. The center of that dimple matches a dimple on the interior of the vehicle. Any other spot on the lower firewall and you have to go through two pieces of metal spaced 2.5 or so inches apart.

I drilled a 3/4" hole in that dimple to run the DME harness for my 3.2 motor. No issues. Plenty of room on the other side, since it's low on the firewall behind the passenger seat.

To expand on what Chris said, that area is a boxes section. So where the arrow is you would have to drill through one layer of sheet metal, and then drop into the box and drill through the next layer into the cabin.

If you drill though the dimple, those two layers of metal are back to back. But there a spot welds in the dimple. I imagine this was done for structure to tie those pieces together. If you remove the spot welds and don't compensate for it (weld around the circumference of your drilled hole) you're taking that structure away. It's probably not going to affect a caged car like yours all that much, but I'm not a big fan of it.

If I were doing it here, I would drill through the box section, then weld in a tube to make a sealed hole in the body. Then feed AN line through the hole and add the ends on after.

Ahhh, now I see it. Just move the Accusump over to the right, drill a hole, install a bulkhead fitting and I'm good to go. So much easier and less costly than running the lines through the old hole.

Man, the stuff we go through for better weight distribution!

Click to view attachment

Thanks for the advice all!

Thank you Sir!

Like so:

Nicely done!

That's is effective & looks good. Nice mod Andy

Nice work Andy.

What is that blue line called? Looks like it just slips on to the fittings.

Aeroquip AQP Socketless Hose

I got the hose and fittings from Pegasus Racing.

Operating range: Up to 250 psi, 300 deg. F
Burst pressure: 1000 psi

Sure looks like a lot easier to work with as compared to the SS wrapped lines. Decided to go that way, but the pliers to crimp the clamps, recommended in high temperature situations, was $80 bucks. Ouch.

Oh well another interesting tool to place in the green felt.

I've been running this setup without clamps for years now, never had a problem.

Well you know where to borrow the special pliers now.

Isn't that Parker Pushlok hose?

As per Foley, "Aeroquip AQP Socketless Hose"

I don't think it's the same, but maybe. I'll have to call the Parker guys in San Jose and find out.

The Parker Pushlok is very similar:
http://www.914world.com/uploads/4281_b1.pdf