I've been writing a little bit each night to try and catch this thread up to where I am today.....
While doing all the other wiring I tackled the FAST install as well. First I had to figure out where to put both ECUs (XFI and XIM). I debated it for a while but I finally decided on the passenger kick panel area. The ECUs have LED diagnostic lights on them and I figured it would be good to actually be able to view the lights. The two ECUs are different shapes and I decided to mount them staggered so that both sets of LEDs would be visible. Like this:
Next I needed a bracket to mount them to, so I designed a standoff bracket to be able to mount the ECUs. So I made a quick bracket out of aluminum sheet and bent a prototype to shape using my workbench and a hammer. It came out decent. However, my best friend’s girlfriend’s father (lol that’s a mouthful) works in a machine shop that has a sheet metal brake. So I cut another one to shape and had him bend it on the brake. It came out much nicer. Since it’s hard to see when it’s in the car here’s how it looks with the two ECUs. The only downside is I’ll loose the normal antenna cable hole and I’ll have to come up with a custom kick panel.
I then used a knockout punch to cut the 2” hole that’s required in the firewall. You can use a hole saw but with the tight under dash area, the knockout punch worked great and went through the firewall like butter. The FAST XFI harness comes with the grommet built in to the harness. What sucks is the XIM also requires a large hole to run it’s harness through as well. To be honest, to make it really nice you should take all the harnesses apart and integrate them like Bob (Twisted Fish) did. I wasn’t that brave because the first time I go to start it and it doesn’t start I didn’t want to be second guessing myself on if it’s something I did. This is where you should build the car first then take it all apart.
Anyway, here’s just the bottom XIM mounted directly to the kickpanel.
And here it is with both ECUs mounted.
Here’s the resulting mass of wires that you have to deal with. Actually the wires aren’t really the problem it’s the relays and fuse holders that take up a lot of space. Especially when combined with the Vintage Air wiring. Once the car is running I’ll get brave enough to shorten wires and remove the add on harness that aren’t needed to help clean up the engine bay (most of the harnesses are too long).
Two things I learned about installing the FAST system. One it ships with a Inlet Air Temperature (IAT) sensor, however that sensor doesn’t work with the harness.
You have to buy a stock Dodge Charger/Magnum SRT-8 IAT sensor (p/n AX109) which is ~$20. Not a big deal but its just strange that they bother shipping the whole setup with a sensor that doesn’t go with their harness.
The other thing is that the Crank Position Sensor (CPS) changed over the years of hemi engines. Of course the one on my engine is different then the one that connects to the harness. The part number sensor I needed was 56028815AA. Here’s a picture of the two sensors, the bigger one on the right is the one you need.
I also bought and installed a Lokar throttle cable. I made a quick bracket to attach it to the intake manifold. I ran the cable through the square hole where the stock accelerator cable ran. I also needed to figure out the heater hose routing (I’m not going to worry about the AC for a while). So I bought a Vintage Air two hole bulkhead. The AC lines I’ll run through the fender well, but the heater hoses I kept in the engine bay. I was originally going to put the bulkhead as close to the heater hose outlets as possible (right behind the intake manifold), but that area is congested with all the wiring. Plus on the inside of the firewall it would be really tight to the Vintage Air box. So I decided to put them all the way over to the inner fenders. This maximized clearance for everything else. I turned the bulkhead at an angle to match the angle of the inner fender. Its not perfect but I think it looks pretty good and its out of the way of everything. It’s still a shame to have to put holes in the firewall that I spent so much time smoothing. Anyway, in this picture you can see the throttle cable and bulkhead, etc. The heater hose was just on there for mockup purposes. I'm planning on getting some right angle hoses.
I think one more post and I'll be caught up.
Travis
72 Cuda