I'm going to outline my megasquirt install for everyone, make it easy for the DIY crowd.
I chose the Megasquirt 3x, as it provides sequential fuel and spark, the fact that I can tune it myself, and the fact that tunerstudio has a 'self-tune' setting that will adjust the fuel tables to match your specified air/fuel ratios. There are a ton of other features that make it comparable or better than the commercial grade offerings. This isn't quite a plug and play, though; you'll be wiring the thing yourself. Go here for a feature comparison between the megasquirt and the FAST - both offer things the other doesn't, but are very similar in most features.
Inputs needed for the megasquirt box:
Crank trigger input (5v power, common ground to box, and signal out)
Cam sensor input (5v power, common ground to box, and signal out)
Throttle position sensor (5v power, common ground to box, and signal out)
Coolant temp input (common ground to box and signal out)
Intake air temp input (common ground to box and signal out)
Wideband O2 sensor (O2 sensor to it's own box, then common ground to box and signal out)
Outputs for my install:
Logic level spark (12v fused feed and box controlled ground, through coil drivers, to fire coils) (more on this later)
Injectors (12v fused feed and box controlled ground to fire injectors)
Idle air control (not installed by me- there is no idle air control on a hilborn) (should be 12v fused feed and box controlled ground to operate)
Fuel pump relay control (via ground- turns pumps off if car not running after 3 seconds in key on position)
Tach signal (single signal wire to run to tach input)
Additional Hemi specific notes:
-For the box to be able to read the Hemi crank sensor, a special pull up needs to be installed in the box. DIY auto tune did that for me for $12 before sending me the box.
-The Cam and Crank sensors are 3 wire - ground, signal, and 5v power. There is only one 5v source on the megasquirt box, and that is the Throttle Position Sensor VREF wire (pin 26 on main MS3 connector). That feed is shared between the TPS, the crank sensor, and the cam sensor.
-The spark output for the megasquirt is logic level - that doesn't work with the hemi coils. So, you need to use coil drivers; you can use either the diyautotune BIP373 version, make your own Bosch BIP373 box, or get the bosch 211 factory part. I am using the bosch 211 version - the most difficult part of using these is finding the connectors, which I outline in the parts list below (and give a source - $27 shipped for everything). Here is a link to info on the Bosch 211 including all applications they were used on.
-buy the IAT and Coolant temp sensors from DIY Autotune; the megasquirt is already calibrated for (you can re-calibrate the settings for other sensors if you want).
Parts list:
Megasquirt 3x box assembled with $12 pull-up: $657
MS3 wiring harness (8 ft): $67
MS3x wiring harness (8 ft): $72
Innovate O2 sensor (MTX-L): $199
Bosch 211 (I bought Meyle): $140 ($70x2)
Bosch 211 connectors: $27 (outlined below)
Factory connectors for injectors, coil packs, cam sensor and crank sensor (and alternator):$100-$200 for factory harness from junkyard
TPS Sensor & plug: $40-$150 (specific to your throttle body)
Idle Air Control Valve & plug: ??
GM Intake Air Temp - open Sensor & Plug: $20
GM Coolant temp sensor and plug: $16.25
Cable driven throttle body: $100-$400
Throttle body adapter (if running GM cable driven throttle body): $60
3 relays: $24 ($8x3, including wiring)
A bunch of extra wire: $60
Buy Tunerstudio & MegaLogViewer software: $60
