AEM Infinity 506 in a 3000GT

[mjannusch]

I ordered one up, so it is going to get done. Documentation will happen here. I'm hoping to make this essentially plug-and-play for people with a reasonably-priced adapter harness and all the necessary information to get it going.

Unfortunately, there's zero support for our crank/cam trigger system for second/third gen cars so currently you have to use a 1G combo CAS with a custom trigger wheel. I'm using a brand-new CAS with a 24 + 1 tooth trigger disc to replace the stock disc. DSM adapter cable works fine for converting the sensor plugs to the combo cas setup.

I ordered AEM's flying-lead harness to get a jump start by having the ECU-end of the harness mostly wired up, and have a female harness connector block for the car-end of the harness to plug into. I'll just have to figure out the connector mappings and wire that all up.

[ChargerX3]

So what are the perks to the 504? This should be fun seeing you build. Surprised there is t a way to make the later gen timing triggers work. Sounds like something Jeff or Greg would know more about.

[DCIV]

Yeah I’m not up to date on my aem versions. What’s so special?


Coop

[mjannusch]

https://www.aemelectronics.com/products ... y-series-5

The Infinity 506 is all airflow-based, and uses VE models and fluid dynamics to compute fuel instead of a static pulsewidth table and a crapload of little correction tables. Essentially it should be easier to get a solid tune because really the only thing you have to tune is the volumetric efficiency of the motor at the various points of the map. After you get that dialed in, then you just tell it what Air/Fuel ratios you want across the map and it should deliver it over varying conditions.

It also uses a lot of sensor inputs to get it tweaked, so for instance you can use fuel pressure as an input and have it correct on the fly for variances in fuel pressure against what's expected. So if your differential fuel pressure across the injector drops to 35 psi instead of 45 psi then it can increase the injector pulsewidth to compensate for that. There's a lot more to it than that, but that's the basic idea. It "understands" more of what the sensors are telling it versus just having static tables to pull info from.

It also integrates directly with the AEMnet on my X-Series widebands, so it gets a CANbus feed of the exact A/F data in digital form instead of going through a D/A conversion at the sensor controller and back through an A/D conversion at the input pin of the ECU - so that should be a lot more accurate - or at least eliminate some of the guessing that I was faced with, and wondering if the wideband readings were accurate or not.

It is also better with flex fuel than what the Series 2 can do. Timing resolution should be a lot better, with a faster processor handling engine events. Logging on it is basically insane, and you can write direct to an SD card for really high logging resolution over a long period of time. It is much smaller physically, so fits better under the dash if you happen to have other things stuffed under there (I do). The software also seems better than the old stuff for the Series 2 as far as tuning goes. Better graphs, gauges, etc.

There are also more choices for add-on gauges. AEM's AEMnet gauge is one that's reasonably flexible, but there are other options like GaugeArt, BTI, AEM's crazy digital dash, etc.

https://www.aemelectronics.com/products ... h-displays

[DCIV]

Sounds really cool! Sounds like a ton of set up for it to be easier to tune though.


Coop

[mjannusch]

Complicated for me to do it the first time through, then after it has been done it will be easier. Could probably convince AEM to make firmware for our crank/cam pattern if enough people are interested in doing it.

[vr4]

I'm kinda surprised you haven't just gone to motec by now

[Chris GTO TT]

[quote=""vr4""]I'm kinda surprised you haven't just gone to motec by now[/quote]

Motec System Exhaust?

[vr4]

[quote=""Chris GTO TT""]Motec System Exhaust? [/quote]

https://www.motec.com.au/gp-models/curr ... series-gp/

Overnight from Jap....errrr Australia

[Jeff V.]

I briefly considered throwing one in the truck just to play with it.

But then I realized that'd be completely stupid.

It should be pretty cool in your car. I'll be interested to see what you can do with it.

[mjannusch]

Had considered MoTec also... And ProEFI. And MegaSquirt MS3Pro or MS3X.

I went with the AEM Infinity just because of my familiarity with how they do things, and easy interfacing into my AEMnet devices.

[ChargerX3]

[quote=""mjannusch""] Could probably convince AEM to make firmware for our crank/cam pattern if enough people are interested in doing it.[/quote]

I think it would be worth reaching out. I dont own an EVO, but dont they run a similar setup minus being 4cyl?

[mjannusch]

Evo is like the DSM crank/cam pattern so it is two edges instead of 3 crank edges. Won't work for us, but obviously they could make it work if prodded in the right direction. The crank/cam pattern is burned into the firmware version, so you can't cook up your own patterns like you could on the Series 1 and Series 2 AEM boxes. :-(

[mjannusch]

My other thought was to make a 24-tooth crank trigger wheel to replace the stock 3-blade trigger. It would be easy, except for the stock part being pressed in the center so it sits offset from the mounting plane. Could certainly make a die to press it, but just isn't as easy as precision cutting a piece of steel. Also not sure how well the stock crank pickup would be able to discern that many teeth at high RPM. I guess I could also make a combo trigger with optos to mount on the rear exhaust cam like the stock cam trigger wheel that would have both the crank and cam teeth on it. Hmmm. Would certainly be easier than messing with the 2G crank trigger hardware, and perhaps accurate enough with the 24 edges instead of 3 (it'd actually be 48 edges on the cam wheel, but correspond to 24 crank edges). Dirt might be a problem there though, and you'd have to use full timing belt covers (and not clear) so the optos would work reliably.

Hmmmm.

[ChargerX3]

I like where you are going with this.

[Jeff V.]

Is there an option for a 32 tooth wheel? 6G75 uses that. The sensor is just a mag pickup. It bolts into the same place as a 6G72 hall effect sensor.

[alienviking]

Take careful!

[DCIV]

I do like where this is going.


Coop

[mjannusch]

We already talked about that crank trigger. Pretty sure that won't work as it has missing teeth in different locations (2 missing at 1/4 TDC, 1 at 2/5 TDC, 1 at 3/6 TDC) and Infinity just wants one pin missing at cylinder 1 TDC only (so has to be a single tooth cam trigger). If it was just 36 evenly-spaced teeth on that crank wheel, then we'd be good to go with just modding a stock cam trigger disc by removing the extraneous teeth.

I mapped out my conversion harness today. Think we're good there. Wish I had a couple more low-side outputs on the Infinity to play with, but not enough to pay another $1100 to get to the 708 with only 2 more.

Need to assemble the cable now, that should be fun.

[mjannusch]

I'm also designing/building something to replace all three center gauges with digital gauges. Three 2.8" TFT LCD displays run off a microcontroller. Should be fun... 3D printing a replacement mount for it all that should fit well and replace the whole stock assembly and mount right up, plug into the harness and AEM with AEMnet (Infinity and Series2). Touch controlled on each of the gauges, though not sure exactly how that interface would work yet.

I have a dash section and spare set of stock gauges and the mount to play with to mock it all up. Electronic components are on the way.

Hopefully get started on the Infinity to 3000GT cable shortly also.