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I'll be using a 951 throttle body and the 951 TPS instead of the S2 one so I know I'll have to rewire that portion of the DME harness.
The 951 harness has 5 wires for the TPS (in a 6 pos connector), while the S2 has only three. Pins 6 and 4 on the 951 harness are for the idle switch, which appears to not be necessary for microsquirt (someone please correct me if I'm wrong). This suggests you can reuse the 3 wires in the S2 harness without having to run any new wires. In theory if you’re careful you can extract the existing pins in the S2 connector and simply insert them into the right places in a new 6 position shell. kayjayco.com sells these for under $10.
Pin 3 in the 951 TPS connector connects to the pot wiper arm, which I think would connect to the TPS ‘sense’ input on the microsquirt (pin 27). The resistance between pins 3 and 1 decreases as the throttle opens, which means pin 1 on the connector would go to +5 Vref on microsquirt (pin 28), leaving pin 2 on the connector to be connected to signal ground (pin 20).
NOTE: I haven’t actually wired this up myself, but I think that’s how it would work.
AND, relying on tech support is not going to work, that's not their job. Your job is to fully understand the Mega-Manual, and work with how to adapt their system to your car. Take each subsytem separately works best. Route wires so that there is no interference between engine and body.
One of the unique issues with running the DIYPNP box is the Mega-Manual doesn't actually cover the DIYPNP kits. It's a 90% solution but not everything is a direct translation. Honestly, I was really surprised there weren't more folks with 16V cars running MS because it seems like it would be an easy transfer. If I weren't using sequential injection or COPs, I could probably have gotten everything wired in an afternoon.
Here are a couple of pictures of the VAG coils mounted on my spare motor. It's been discussed in other threads, but the VAG 1.8T coils are just a hair too short to fit perfectly. Others have used M4 stand-offs to extend the spark plug for a good connection. I can't confirm personally, but it seems the 1.8 FSI coils are about 8-10mm longer and don't have this problem. I picked up the 1.8T coils on Amazon for about $20/ea and they were genuine Audi parts. Surprisingly, the electrical connectors were more than the coils! I lucked out and bought four connectors for $30, but they're normally $30/ea!
One of the guys in Europe building a 16V engine brought up the VAG FSI coils and has posted pictures confirming the fit. Unfortunately, I found out after I ordered mine. I'm actually glad I went with the 1.8T coils because there are a few success stories of guys using them with MS setups. The wiring is straightforward enough that even I can wrap my head around it.
As far as the intake, it's an SFR intake, one of the 2nd Gen that isn't prone to internal collapse. I bought it from a fellow RL'er that had another custom intake made that he was happier with. Realistically, if I had any fabrication skills it wouldn't be exceptionally difficult to make my own.
One of the guys in Europe building a 16V engine brought up the VAG FSI coils and has posted pictures confirming the fit. Unfortunately, I found out after I ordered mine. I'm actually glad I went with the 1.8T coils because there are a few success stories of guys using them with MS setups. The wiring is straightforward enough that even I can wrap my head around it.
As far as the intake, it's an SFR intake, one of the 2nd Gen that isn't prone to internal collapse. I bought it from a fellow RL'er that had another custom intake made that he was happier with. Realistically, if I had any fabrication skills it wouldn't be exceptionally difficult to make my own.
Out of curiosity does that SFR intake have internal bellmouths?
Also, the 1.8 coils do fit with some tinkering. The LS1 coils are MUCH bulkier and since they are not meant to sit ontop of the spark plug, they are not nearly as clean an install at the audi coils and they mount a bit strangely in my car. I picked them for their robustness and for their incredibly high energy spark. I'm happy with them and have no plans on switching to the audi coils. They (the audi coils) are a nice, clean, stock looking set up though.
What do you guys think about Subaru ignition? It's one unit with built in igniter, and would mount cleanly somewhere off to the side with h/t leads to the plugs.
A friend of mine is getting a lot of parts from a wrecked Forester and I may get it for peanuts just so I can mess around with it. I think MS could control it fairly easily.
@Dougs951S; The intake doesn't have bellmouths, I don't know if anyone makes a 16V intake with them, possibly Michael Mount? And if I were building an 8V engine, I would definitely use the LS coils, they provide an incredibly strong spark.
@Sausagehacker: I'm not sure what Subaru ignition module that is but the Mega Manual describes multiple Subaru ignition options.
I tested my VAG coils' resistance this weekend and it appears they're the correct ones to play nice with MS, they're the low resistance ones. At ~$20/ea, definitely happy with my purchase.
What wiring problems/issues/successes have people had?
16v Turbo 9:1cr
MS3x with the MapDaddy upgrade
Staged Fuel Injection
Sequential Ignition on 2.0 tfsi coils.
Custom Traction Control utilizing the JbPerf MS ignition and injection board.
- Boost Controlled by Gear, TPS, and RPM
Complete Custom Harness with a 55 pin milspec on the firewall.
Needless to say, when this weather breaks I have a fair bit of wire to run.
I'd like to move this discussion over to the topic of wiring. Doug, I know you wired your MS through a scavenged DME case to jumper to the factory harness. What did you have to add to the factory harness to support your MS?
@Stage5; Is it a correct statement you haven't completed your wiring harness/don't have a running car at this time?
Question for the group at large: For COP, where would you grab the switched 12V feed for the coils? Looking at the MS, it doesn't appear there is an output for switched 12V to easily feed to the coils. Maybe someone else has a different perspective?
My 16v currently is still a work in progress, but is not the first 944/ Megasquirted car I have built/ played around with. And I do have to agree with Doug, this platform has been.... different. This 16v build, however, is far more involved then any other I have done!
As for the 12v switched, my favorite method is to use a Relayed fuse block with a inline breaker between it and the battery. The pic I have attached is a Painless Wiring Unit and worked flawlessly in ever application I have used it in; plus it provides you with a few extra accessory power outputs. I personally like to use a fuse tap to trigger the relay from a circuit that only powers on in the "ON" position instead of the "ACC" position (usually the Windshield wiper circuit.) Then just ground the 12v against the engine block or direct to chassis. Use the appropriate inline fuses and its done.
I'd like to move this discussion over to the topic of wiring. Doug, I know you wired your MS through a scavenged DME case to jumper to the factory harness. What did you have to add to the factory harness to support your MS?
@Stage5; Is it a correct statement you haven't completed your wiring harness/don't have a running car at this time?
Question for the group at large: For COP, where would you grab the switched 12V feed for the coils? Looking at the MS, it doesn't appear there is an output for switched 12V to easily feed to the coils. Maybe someone else has a different perspective?
The 12v for the COP comes from the stock coil +12v on my car, which gets it power from the ignition switch. The wire is plenty large enough to support the current draw of 4 coils. I had to add the high current ground for the coils, it goes directly to the battery. I also had to run wiring out from the MS into the engine bay to provide two channels of logic level 5v trigger signals to fire the two coil pairs, as well as a single low power "common" to return both 5v logic signals back to the MS. Its worth mentioning though that all my sensors use the same low power common to return the 5v signal to the MS. There is only 1 "common" wire and it returns signal for the all of the ignition coils, the IAT, and the MAP sensor.
As far as adding things, I reused as much of the factory DME harness as possible (since it was a pretty fresh, low miles harness out of a wrecked 89 TS) and gutted the KLR entirely. In addition to the low power common and the ignition coil wiring described above, I had to add a separate, "adjunct" harness I made up which contains the 6 wire runs for the MAP sensor, IAT sensor, and TPS sensor (since the TPS has its own low power ground to the MS, it has 3 wires while the other two sensors share the ignition coil common and only have 3 wires between them. two are for the map and one is for the IAT)
Because I reused the factory engine bay harness and fusebox, everything works like stock. The ONLY thing that doesnt work on my car is the factory boost gauge. There are two different workarounds for that issue as well if it truly bothers someone, but I have nice gauges in my car and until I started typing this response, I totally forgot our cars even had a factory boost gauge since its been so long since mine has worked.
In addition, I had some pretty serious noise injection issues at first, I had to solve it via some clever hardware filtering. There is more information concerning all of that HERE>> https://rennlist.com/forums/924-931-...-my-car-3.html
Later on if people are interested, I might talk a little more about my knock sensing setup which uses factory wiring and the factory knock sensor fed into the MS via a KnockSense unit purchased HERE>>>>http://www.viatrack.ca/ It is capable of real time progressive ignition retard and operates completely behind the scenes exactly like the factory KLR.
I will be installing my ms2 ecu in my 87 951 very soon, I had it in a N/A 83 with all the sensors working just needed to hook up injectors. Well that car is long gone so it is time to take the plunge and install it on my turbo.
Doug I will have some questions for you in the near future.
My plan is to take it slowly and for starters get the MS monitoring everything then get it to do fuel and then spark. I will have questions for you guys about the COP successes you have had because I am certain I will be going that route.
Jeff, could you expand on your previous 944 running MS? What Porsche/Bosch sensors did you keep and what sensors did you add? How did you wire everything together? What difficulties did you encounter?
02-26-2015, 02:55 AM
