Open Road

   

I think Stirling was documenting his use of the Link system on RL and he figured out the various wires to match up with the 928. However, a while back he deleted his files. I'm pi$$ed that I didn't keep a paper copy. He did all the homework.

   

Dave K9 was using the “vampire” ECU system, but I believe just as an independent knock monitor and not as a true ECU.

Maybe Stirling can jump in here (928Bigfoot).

Link is the way I would go, no question. Helps that a fellow 928 owner is a dealer here in N. Texas and has the dyno to tune it.

   

I'm wiring up my link thunder right now. ton of options, and features. I built a spreadsheet and a bunch of other docs on it. You can go simple or you can go full tilt. I'm doing coil on plug, sequential injection, also tying into the ABS for traction control, also using alcohol content sensor so I can run e85 or a blend, as well as datalogging oil temp & pressure, fuel temp and pressure, as well as trans temp. Since I'm using a T56 trans I'm running the speedometer sensor feed through the ecu as well and letting it do the math conversion for the factory 928 dash. The ecu can also activate the reverse lockout solenoid below a certain RPM (mine will be 3mph) The link is also capable of a simulated injector pulse output for the later digital dashes so you can calculate fuel economy and miles to empty. looping the starter signal through the ecu also gives you the MB start (where you just bump the key and the starter cranks until the engine starts) you also get some cool features like gauge sweep on startup so you can see gauge problems as they develop. (Water temp, speedo & tach)

Link thunder can also run and monitor dual knock and dual oxygen sensor as well. Some of the cheaper ecu's have most of the features, but the thunder has the most inputs and can drive 8 coils and 8 injectors sequentually. when you add that to dual knock, dual oxygen sensor as well as the digital inputs that you can tie into abs I wouldn't really recommend any other model. The thunder can also support e throttles, as well as has a built in pwm controller for cooling fans. (I will get to that later)

Also the link uses AMP super seal connectors and those are awesome for pining and depinning.

Also link has fantastic support forums and they are really helpful.

There are 2 of us that are wiring up our links now, and one was installed in a stroker from Kansas for a while.

PM me your email address and I can send you what I have. I removed it from RL because I don't support IB's business model.

   

Thank you.

PM sent

   

Shifted wrote: ↑Thu Sep 24, 2020 11:33 am Did you receive my PM?

I did not.

   

   

The Link Thunder has all the stuff you mention and more. I think Hans is using the MAX ECU. I just really liked the Link support forums. Support after the sale is just as important as the features you want. I couldn't find any comparisons between MAXXECU and LInk. I did find a ton of Link comparisons to MoTeC which is the gold standard.

It is your choice, so make sure you are 100% sure before you pull the trigger. The MAXX is a little cheaper than the Link, Also look at the wiring options. The LInk uses AMP superseal connectors so if you munch up a connector housing they are cheap and easy to find. they are also very easy to pin and de-pin. When you are doing an ECU it is almost impossible (especially on your 1st one to plan for everything, so you will be depinning and re-pinning the connectors.

they other thing to keep in mind. do you know a tuner locally that knows or likes a specific ECU? It's best to couple what you want, with who is going to tune it. If you don't have any tuners that know or endorse or sell the MAXXECU that that will be a tough project.

   

I went with dual LSU 4.9 for mine, dual knock as well. I think the link support in the forums is fantastic. I had tons of questions as a guest user, before I even purchased an ECU and they were patient and helpful along the way. I even posted questions about wiring and they helped as well. They are super helpful with people that have tuning issues. Someone posts a description of the problem and uploads their log file, and they get an answer, & I see people go away happy. I have no benefit from anyone else buying a Link ECU. I just think it's a better solution. For me access to local tuners and support were the biggest deciding factors. I've dealt with motec support which sucks and they are the most expensive solution and they push everyone to pay the dealers and they only support the dealers. I've also talked to other link customers that had problems and like support does not tell you, that is a 5 year old ecu we won't help you. People show up in the forums all the time with really old stuff and they support it. I sold my motec because while it was supposed to be "supported by the dealers" no one would touch it.

While wiring up an ecu isn't rocket science, but it does get pretty complex. I have 48 wires just for COP and injectors, start adding dual knock sensors (8 wires), Cam and crank sensors (another 5 wires) dual Oxygen (another 12 wires) Combo oil Temp and pressure (another 5 wires) Alcohol content combo fuel temp sensor (3 wires) Fuel pressure (2 wires) Speedometer input (1 wire), AC request (1 wire), and add a few more (trans temp, 2 more wires) then adding the relays and you get pretty complex really fast. Oh, I forgot reverse lockout and fuel pump outputs. 2 more wires and 2 more relays.

This is my second ecu and harness in a 928, and while I'm not a pro or a shop most DIY folks mess it up and end up at a shop or end up with a rats nest of crappy crimps and just a general mess. I've also seen ECU's installed by shops that looked like crap as well.

I am using the MaxxECU Race for my supercharger builds. Its a very good choice when considering cost. It far and away the value champion.

The runner up would be the EMU Black, and if you are doing a plug-and-play system, likely what I would recommend.

Of course, I am looking at cost from a dealer/jobber perspective, so the pricing is different than standard retail.

When considering an ECU for an 87+ car, you have several considerations/requirements if reusing the stock harness: dual distributor control (not supported by all ECUs), dual knock sensors, batch injection on single or and ganged output for current capacity. Bonus would be integrated WBO2 controller to avoid extra wiring.

This cuts the list down considerably.

The only units out there designed for an end-user programming (there are truly programmable computers that don't even have fuel models or USB/Ethernet interfaces and require CAN or LIN style converters) that fit the bill for the S4 with integrated WBO2 and under $2k retail in order of cost (lowest to highet):

VEMS
EMU Black
MaxxECU Race
AEM 508
Link Thunder

Hope that helps,
Hans

   

The EMU Black really doesn't have a downside in a plug-and-play application, apart from the somewhat clunky software interface. It probably makes the most amount of sense for plugin, as the documentation and support is very good (VEMS is almost impossible to just jump in with, as there is no user manual and limited support).

When looking at a complete wire-in solution, the EMU was natively designed as a 6-cylinder control system, and while it works in an 8cyl application, you have to run wasted spark and there are other small caveats. Again, none of these are an issue for plugin, as you only use two ignition outputs, and one injection output in that application.

Hans

   

The Maxx has internal logging, so you dont need an external device. The EMU does if you add the EDL-1 unit. However, once you start adding all the external modules, the cost advantage really starts to go away.

I think it really depends on wire-in vs plug-in. If you are doing plug-in, then you are kind of using a bit of blunt tool (batch injection, limited sensor inputs and data collection) so it kind of makes CAN logging a bit silly. If you are going wire-in, and dedicating all that time and effort to replacing everything and going full sequential, monitoring pressures and temperatures at every point, then its silly not to collect and analyze that data.

Regarding the LSU sensors, almost everyone I have talked to says there is not much of a difference from a usage standpoint (when looking at the standard sensors), but the older 4.2 may be a bit more robust a sensor from a lifecycle standpoint. The 4.9 is not leaps and bounds a better sensor or anything. It is more important that the sensor is implemented properly in the hardware than which it uses. The EMU does not use the Bosch driver IC inside the Black, it instead uses a proprietary discrete input (unlike their Lambda-to-CAN module which is considerably more expensive as it adheres to Bosch design). In any case, I would take any ECU with internal WBO2 controller over an external CAN any day, as all the latency, coms problems... etc are avoided.

   

   

I thought the exact same thing about that 8mb of storage.

I even asked them about it.

They have some crazy data writing algorithm that does de-duplication somehow, and they can get a pretty sizable log in there. I think they said something like logging all channels for a 24hour endurance race.

If you are going for dual sensors, then you are looking at either external controllers, or big boy ECUs, which are well beyond the plug and play scope. There are some Motec units, the new Haltech Nexus, the old Link Thunder, the AEM 708, or the Emtron KV8. Outside of those, you step up into the more flexible, but essentially clean-sheet design ECU where you need to create your own fuel model and timing patterns, like the OBR or Engine Lab... or something in between like the Life Racing/Syvecs.

If you are going to spend that kind of cash, the Emtron is probably the best all around package, but you are looking at $2500 for the ECU, plugs and pins.

   

I am in NO way offering any ECU product. Just sharing what I have found in case its of help.

I am only ever going to offer control systems for my supercharger builds. I have zero desire to support or educate people on control systems, fuel modeling, ignition timing.... etc. I personally an not offering anything, and using the term "plug and play" in reference to reusing the stock harness, and ignition output system.

There is no true way of offering a plug-and-play system for the 928 unless you want to maintain a MAF based system. Any other configuration will require removing the MAF and making an adapter harness to reuse those pins to send back AIT and MAP. The factory TPS wiring can be reused, but the sensor also needs to replaced with a variable instead of trinary switch.

I did make adapter boards several years ago when I was looking at doing that, but ultimately I decided to make complete replacement harnesses, as it is very difficult to troubleshoot harness shorts remotely over the phone. and most of these original harnesses are deteriorating.

It will be interesting to see what you come up with. AEM does make a good computer. I was looking at using the 508, but ultimately decided on the Maxx as it has more flexibility for some advanced control strategy and I can use arbitrary math channels to do things like backfeed the digital dash correct fuel consumption data. The AEM is solid hardware, and the software and documentation is pretty decent too. The 708 is kind of in a strange pricing area though, and I would lean towards a KV8 over a 708. The 508 on the other hand is competitively priced and worth looking at if you don't need to program any unusual functions.

   

Here is what I did to interface the factory harness. If your plan is to reuse the stock wiring, you honestly dont need two wideband controllers, as you only have one usable injector output, so it has to average all cylinders anyway. Keep us posted on your progress, but I would suggest you not go crazy on the computer if you cant use the functions yet pin-wise. There will be a whole new wave of controllers out in mid-late 2021. People are holding back the releases on everything because SEMA and PRI were cancelled this year.

Get something that makes sense for the limited capability of the stock harness, and buy an expanded unit when you decide to replace your harness.

Nice piece Hans!