Everyone,
I’m posting this to document the conversion of standard SN-95 ABS from my FOX Mustang over to the new “oh my God” Ford Racing ABS…
The first thing to consider is the location and mounting of the ABS unit itself. My SN95 ABS unit is/was in the passenger floorboard. Therefore, I already had all the lines (2 supply and 3 outlet) run around the car.
The stock HCU bracket could be easily manipulated to mount 2 points to the floorboard and I built a simple spacer to mount the third point. The mount has plenty of vibration isolation, so you can grab and shake the HCU in the mount. This gave me good feelings that vibration from the car during a race would not cause excessive issues with the HCU and ABS electronics.
The stock supply lines and outlet lines were “close enough” to just cut and flare for a simple union fitting. For the new lines going into the HCU, I just purchased AutoZone double flare 3/16 line. This was good for 2 of the 6 lines, but the other four required that line, but a M12 conversion nut to be purchased. You can also get these at AutoZone, etc. I also removed the rear prop valve, as the FR500 unit does that on it’s own. I did have to run a second rear line, as the S-197 system is a 4 channel and the SN95 is a 3 channel system. This consisted of just another few sections of 3/16 line running parallel to the original rear line.
If you want to flip flop back and forth between ABS/no ABS, install the prop valve in the rear supply line BEFORE the HCU. That would allow you to run wide open (no pressure drop) for ABS function, or reduce the pressure if the ABS is disabled. I chose not to do this, as I’m going to “set it and forget it”.
The only harness you need to source from a junk yard is the ABS plug.
Here is the plumbing layout for the HCU
Here is the wiring diagram. For older cars, I just ignored the PCM portions.
The brake position switch can be made from a 5 pole 30A relay.
The speed sensor wire colors from the SN95 system match this diagram, so that is pretty nice…
I don’t have any pictures of the wheel speed sensor mounting, but it’s a simple redrill/tap for the new clocking on the S-197 sensors. The SN95 were just a magnet pole sticking out, so there was no orientation required. To drill/tap the rear caliper brackets, I found it easier to just remove the axles from the car and remove the caliper mounting plates from the axle and drill on a drill press.
The front spindles on my car didn’t want to come off easily, so I drilled by hand on the car. Not the easiest, but worked fine.
All in all, I would put the installation difficulty at a 6 out of 10. Not super difficult, but time consuming to lay out in your head and then it’s just time… Having a welder, drill press, and overall shop tools was nice, but you could probably get away without them.
I’d say that since I had ABS on the car already, this entire conversion (not counting my time) was about $1100 in parts
$525 HCU
$50 ABS harness
$125 wheel speed sensors
$260 FR ABS Module
$25 Brake Fluid
$75 Brake Line and fittings
$25 Diff fluid and gasket
$15 5 pole relay with harness
The only thing I haven’t addressed at this point is the diagnostic port (Module Communications Network) section 14-2 on the diagram. I still need to do research on how to wire an OBDII port to these wires so I can trouble shoot the system.
Here is the parts list of what you will need to buy…
GT500 HCU
7R3Z-2C215-C
ABS Module
You want the "M-2353-A" sensor. The -A part is the FR500S module. The -B and -C are the same module for the new Boss cars, just with or without the bracket. I would guess the tune is for Pirelli slicks.
http://www.fordracingparts.com/parts/search.asp?q=2353
Wheel Speed Sensors
BRAB-290 (rear)
BRAB-291 (front)
http://www.autopartstomorrow.com/par...whl-abs-sensor
This is the cheapest place I could find and it was free shipping. They are Motorcraft parts.
These sensors plug into the stock SN95 plugs and are approximately the same length as the SN95 harnesses, so you shouldn't have to manipulate the body harness.
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