AEM EMS vs. MSPNP2
 

My '95 drivetrain is mostly stock but I have a used AEM EMS(30-1710) ready to install along with a Begi-S(GT2554)+intercooler kit and 650cc EV14 injectors and an Innovate MTX-L wideband(already installed running on simulated narrowband for the OEM ECU at the moment).

A friend of mine has a very lightly used MSPNP2, but it is illegal in the autox class he wants to run in because he isn't allowed to add a MAP sensor to the car and he doesn't want to tune with the bandaid solutions available to make it work without a MAP sensor signal. My AEM EMS has the ability to run off the stock MAF sensor without a MAP sensor. He has offered to trade ECU's, and I am considering it. For arguments sake the original ECU price isn't an issue for this ECU comparison.

His '94 isn't boosted and he is going to pay to have his car load dyno tuned so ECU and software isn't as big a concern to him, the tuner can do both. I on the other hand am a cheap bastard am going to road tune my car, plus I want to learn the software so I can tweak it myself... then I'll come to my senses and have it load dyno tuned probably. :)

I have done a fair bit research on the AEM EMS and both AEMPro & AEMTuner software. I've read all the manuals and have read the books, I feel like I'm confident to teach myself how to tune the car with the AEM even though there is a much smaller knowledge base than the MSII and TunerStudio. But this being my first turbo install and my first time programing an ECU, would I be better off going with the MSPNP2 over the AEM EMS?

I don't know as much about the MSPNP2 and TunerStudio. Both ECU's are PNP and use the stock OEM sensors coming through the OEM harness. Both should be able to use the TSE 12-tooth crank wheel, MSPNP2 with a tooth removed I believe. Both can do COP's. Both can do EBC. Both should be able to be full sequential. Both can 2-step rev limit and flatshift. Both have a version of auto fuel mapping. I am going to be running under 15PSI boost and am a little concerned that the MSPNP2 internal MAP sensor would provide poor resolution compared to an external AEM 2-Bar MAP sensor that I was planning to feed the AEM EMS with.

AEM EMS advantages might be:
Slight higher resolution fuel and spark maps
TPS/RPM based EBC maps
Programable traction control
In box VVT control

MSPNP2 advantages might be:
Easier software to use with a higher user base and a lot more information available from end users
Internal MAP sensor(only an advantage because I don't have a MAP sensor yet and it's one less thing to buy)
Fuel/Spark map switching
Superior knock sensing solutions
Built in low impedance injector drivers

I am sure I am missing a lot of advantages/disadvantages but those are the ones I could see at first, let me know if I'm missing something obvious or made any mistakes in my assumptions. If anybody has direct experience with both AEM EMS(30-1710) and MSPNP2(or more likely DIYPNP MSII) please chime in on which ECU you prefer and why.

For the record, you can get the Gen 2 MSPNP working on a '94-'95 in alpha-N mode if you don't want to use the MAP sensor. We don't have a base map for this, but it's pretty straightforward to set up.

If you are using the TSE wheel for full sequential, you also have to modify the CAS to produce a single pulse per cam revolution. With this change, you do not need to remove a tooth.

Resolution with the 4 bar MAP sensor and the MS2's 10 bit analog to digital converter is less than 1/2 of a kPa. It's actually better than the MS1 on a 2.5 bar MAP sensor.

MSPNP Gen 2 has this too. You can specify either duty cycle or target boost based on TPS and RPM.

Thanks for the clarifications Matt, my buddy didn't want to use alpha-N mode or MAF signal to MAP signal converter boards some people have tried. I am leaning heavily towards the MSPNP2 primarily because it seems to have a more fleshed out knocksensing controls than the AEM. What I am essentially giving up would be a traction control and a bit of fuel/spark table resolution, and I could always get a VVTuner if i go the VVT head route. I also now see that if I change a jumper inside the MSPNP2 box I can attach an external 2-bar MAP sensor for even better resolution and not have to route a vacuum signal to the ECU.

im kind of in the same boat. I have a festiva with a b6t, i want to run COP's and start building for more HP. I originally had MS1 on my festiva but it always had a missfire, the builder gave up and suggested a new ECU. I decided i was either going to go ms3 or EMS. I found a good deal on here for a EMS so i picked it up. It may have been cheaper to go Ms3. I will be using a miata engine harness, due to i wont be using all the factory sensors it may have been easier building a harness from scratch for the ms3. Also i need to buy the sensors such as Map, TPS, IAT, CAS. The advantage to the EMS is i can take it to any of the local shops to dyno/trouble shoot. (it will cost a arm and a leg) the guy who built the MS1 for me is as well going to help me with the EMS but now after he has had 4 MS cars running he is really pushing for me to just buy a ms3 rather then learning the EMS software.

I have both Ems v2 and mspnp (AEM on a 440whp s2k and ms on my fe3 itb miata), from a straight user stand point the mspnp (and esp megalog vs aemlog) is way easier to use and get fimiliar with.

While the AEM is a nice unit, its just not as user friendly and you will have abit harder of a time tuning it if you are new to aftermarket ecu's.


-Dean

Personally I would suggest not going ms2, the firmware is at the end of life for any new features, only bug fixes are being done.
I would just reuse the AEM if you have one for now.


Sclippy96 tell your friend you can run the MSPNP2 on a maf sensor for fuel and spark and don't need a map sensor at all.

I love these stories. I remember a few years ago when I called around to find someone to tune my car and every other shop I talked to told me MS was archaic, dangerous, and whatever else they came up with and that I needed to buy whatever they were selling. "You need to spend $3000 on this computer and give me $1100 to tune and $700 to install this or your car will burst into flames. Yes, your $600 MSpnp just turned into a $5000 affair."

Regardless of its life-cycle, does it run engines and features we need on our cars and do it well? I have MS1 on the turbo car and don't get me wrong, I'm excited about going to MS3...but it still runs wonderfully and there is no real reason to change it.

AEM has much better, more flexible, and faster datalogging than MS2.
The boost control is more flexible (but it is PI and not PID, I added a circuit to do the D)
The way I run it is I use:
- boost target vs RPM and TPS
- duty cycle vs. target curve
- duty cycle vs. boost error curve
- duty cycle Integral vs. error
- duty cycle vs. RPM and MAP


It has per-cylinder trim for spark and fuel. Tuners who have tried it have said that when running pump gas close to a motor's knock limit it helps a ton.
(In my case I reached the limit of my turbo (2560) before getting real close to the knock limit.)

The UI of the tuning software, is better AFAICT. Very customizable display.

The tuning software of AEM is much more flexible - this is where people say "it's difficult" - but it has templates for say, idle, revlimit, advanced fueling, etc. Then it's no more difficult than others.

If you have experience tuning, you will really appreciate the AEM's flexibilities.

As to logging, you can choose whatever variables you want to log, including internal variables. You can choose the update rate of said variables. The AEMlog software is free and pretty flexible. It can do XY plots, and you can run equations on the fly (e.g. (Fuel_pulse-dead_time)*AFR/MAP) in order to derive V.E., or "smooth3(derivative(RPM)" vs. RPM to derive Torque.

Knock sensing is a wash between the two. Where did you get the impression MS2's was better?

Thanks for the input guys, I ended up swapping the AEM for the MSPNP2. I was getting familiar with the AEM software, and it's does seem a bit more powerful than the TunerStudioMS, but this being my first time programming an ECU and installing a turbo I think the simplicity of the MS software might work in my advantage, less stuff to screw up.

I can now see the knocksensing is fairly equal between the two choices. The more I read about the knock control I see that it comes down to proper sensor selection and signal damping/filtering to feed the ECU a nice filtered knock signal to read.

I'm up and running on the MSPNP2 now, I gotta tweak the VE tables pretty heavily tho, I'm idling down a few hundred rpm at 10:1 and light throttle will give me 20:1 AFR. Anything more than 25% throttle looks pretty stable around 14.7:1 tho. The MSPNP2 base VE fuel table numbers looks fairly low in low in the low kpa cells compared to many VE tables Ive seen posted, I am guessing this is why I'm seeing such lean numbers on light throttle. I'm incrementally un-newbing myself, but it's a slow and steady process.

I will admit that I'd probably have an AEM in one of my cars if they weren't double the price of MS. Then again, we also have a team of people here at Miataturbo who will educate you. Everything I know, which isn't much, I learned from the "open-source" nature and or MS and the community the educates functional retards like myself.

P.S. AEM series 1 datalog rate into a laptop is at 20 Hz, internally is 200 Hz max.

hmm what injectors are you running sclippy?

Stock 254cc injectors at the moment. Once I have the software figured out I have 650cc Ev14 injectors to install:
Attachment 185971

Thanks for pointing this out, something I totally missed in my first comparison. I should try and figure out what the datalog rate is for the MSPNP2 to see what I'll be missing now.

The individual cylinder trimming is also a very good catch, I knew that the AEM did it and assumed that the MSPNP2 did it too, I was mistaken.

The MSPNP2 is marketed as having an upgraded knocksensing capability over the MSPNP in their advertising for it, i.e " knocksensing" headphone jack, that is why I initially thought it had better knock sensing than the AEM, seems the headphone jack isn't as crucial as it's made out to be... but to a noob it sounds good. :)

datalogging rate varies on ms2~, bit all over the place also you can't datalog internally so you can't get high resolution logs like that at 200hz.
MS2 can do fuel trims pre cylinder but not spark trims.

MSPNP Gen 2 has individual cylinder fuel trim but not spark.