Rustman

I'm in the process of installing an EFI system on my 66, and I was curious where people have mounted ECUs and/or MSD ignition boxes. I was thinking my passenger side up against the rear of the wheel well underneath the expansion tank would be a good place, but would like to hear what other people have done.

j_66chevelle

After checking with Holley on how waterproof I mounted mine on the driver side inner fender facing the firewall

cbernhardt

I am in the process of installing a Holley Dominator in my '59 and I finally placed the ECU under the passenger seat, primarily for protection against weather, dirt, dust and possible stone damage, but also for ease of wiring. Note that I have C4 seats in the '59 so I can access the ECU fairly easily by removing the seat cushion.

Charles

Donny Brass

there is room behind the radio

Rustman

I should have said that I also have A/C, so driver's side back of the wheel well is taken by the battery, but that is the same idea I had but with the passenger side.

Didn't think about behind the radio

ohiovet

On my 57 Corvette Gasser I mounted the MSD ignition box on the right inner fender behind the core support. The Fast EZ EFI 2.0 ECU is mounted under the dash on the firewall.
The ECU and the ignition box should not be mounted near each other and the plug wires must not be run near the ECU.

Steve Stone

I have 2 MSD boxes & 2 coils. One pair runs the engine and the other is backup. My first MSD box, which was installed in the early ‘70’s, failed after 25 years of use. When I got my new engine in 2007 I ordered it with a complete MSD system. I decided to install my old system so when failure occurs that I will be able to switch over to my backup with little effort. I have been using the mounting location on the inner fender facing the engine since the early ‘70’s. The other location around the corner, and perpendicular to the engine has been used since 2007. I do switch over to my backup every 2 years or so and leave it in operation just to make sure both are operational. No failures since the first box failure. The coils are mounted on the fire wall next to the master cylinder.

Regards,

Steve Stone (original owner ’63 triple black convertible, 548,000 miles)

Rustman

How close is too close?

ohiovet

On a fiberglass car RFI can travel further then in a metal car so placement of the ignition box and the ECU is more critical.
My MSD box is probably 3 feet from the ECU which is mounted on the cabin side of the firewall. The ECU is mounted on a metal heater delete plate which also helps with RFI.
No spark plug or ignition wires run near the ECU.

Rustman

What then about mounting either ECU or ignition box on the passenger side near the heater fan? Do you think the blower fan will case any interference?

tomcatz

Splash shield, passenger side. It is metal - mounting fasteners will not pull out. It easy to drop down to get access to the box if need be. Shields are replaceable. Not drilling holes in fiberglass. Have not had an issue with water intrusion (MSD digital programmable 6al2) I do cap unused / grease the connectors

wmf62

on engine side of the passenger footwell/firewall

Bill

vettsplit 63

Same place I mounted mine. I just used Velcro. Some on here didn't like that, but it has worked well for me.

ohiovet

FAST recommends the following:

Avoid mounting locations that expose the ECU to extreme heat or that combine it to a closed area with no air circulation.
The ECU should not be mounted close to electrically "noisy" components. In particular, keep good spacing (try 2 feet minimum) from ignition components (ignition boxes, coils, distributors, etc.

MSD says the box can be mounted in the engine compartment away from direct engine heat sources. It is not recommended to mount the unit in an enclosed area such as a glove box.
Bruce B

65BotaHam

I have both on my 65. The MSD 6AL is mounted on the passenger side inner fender. The FAST EFI controller is mounted on the driver side inner fender. Basically both units are above the vents on the finder, one on each side.

The 6AL is pretty much set and forget. While the EFI can be the same, from time to time I do plug in the handheld to the unit to look things over. I mention this as a reminder that access to the EFI controller plug may be needed from time to time.

ohiovet

The location of your MSD box and FAST ECU sound ideal.

I keep my FAST EFI 2.0 handheld plugged in all the time to monitor engine conditions, AFR, timing, temps etc and performance even though I also have analog gauges.
Also for making AFR and timing adjustments.

ohiovet

Velcro sounds good. I would think the Velcro also helps with vibration.
Good idea.
Bruce B

Grampy

On my 66 I put the ignition box where you are thinking on right side inner fender as high and right as possible. The Holly HP ECU is mounted on an aluminum ground plane behind the glove box. The ECU is avery tight fit and it might not fit with AC.

Grampy

65BotaHam

Nicely done Grampy.

Rustman

The air box for an A/C car is about the same height-wise under the dash, so I think the ECU would fit like your setup, I just wasn't sure if it was ok to put the ECU behind the dash like that. As for where your ignition box is, on a A/C car, a MSD box without vibration cushions measure about 1/2" from the blower motor. But I like the space and was thinking of putting the ECU there, but as I mentioned above, I wasn't sure if the blower motor while spinning would interfere with the ECU.