Why aftermarket computers suck....

[ryan.hess]

-VSS throttle follower? - no

That's a BIG one for me. IMHO, all computers should have a VSS input. if it doesn't, I wouldn't get it.

the reason im going stand alone is cause its so much more simple to tune, and datalogging is so much nicer, and there are programs that you open your data into, it makes corrections for you. id much rather spend 10-15 minutes on my laptop between rounds instead of 30+ with a stock ecm and an emulator.

Simpler to tune? Yes. Nicer datalogging? No. There's also some people working on autotuning, which would be a huge leap forward...

-controll high amounts of boost - Yes... Do you NEED more than 30lbs of boost?
-controll nitrous - No, unless you want it to be RPM activated, then yes.
-2 step - No, it can't dance the 2 step
-soft touch rev limiters - No
-tractiong controll through retarding timing - Yes, I believe it's called "launch mode"
-run a shift light - Yes
-have the ability to data log anything (megasquirt gpio board will have inputs for anything you want to log, egt, 2nd o2, oil pressure, fuel pressure, ect) - Yes, I'm logging wideband data right now
-simple to tune - Not really, there's no "instruction manual"
-controll 2nd set of injectors - why?
-controll any injectors, high or low impediance. - Yes

You mentioned using the GPIO board to control emissions components. I really don't see that happening. Take the EGR for example. It's opened ONLY under low load conditions. I can see how you can write a program to do that, that's not the problem. The problem is, when the EGR is open, you have to change the VE table, and possibly change timing requirements. I don't think it can do that, but I could be wrong.

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[timg]

FYI- AEM, Autronic, Motec, Big Stuff 3, and many other GOOD aftermarket ECU's have all of those features and more. Most of the ECU's aimed at V8's (Holley, Accel, older FAST systems, older Haltech and older Electromotive) are very poor engine controllers and lack any sophistication whatsoever.

I have an AEM standalone on my S2000. It has everything you mentioned plus boost control, WBO2 support, 2 step rev limiters, traction control, soft-hard rev limiters, antilag, nitrous control, water injection control, and a HUGE variety of other standard features. It runs the car just as well as the stock computer and has added abilities. The only place it falters a bit is starting. It takes an extra crank or two to sync timing before firing up.

The AEM isn't even one of the best EMS's on the market- I would call it midgrade. It's head and shoulders above many other EMS's though (especially those aimed at domestic V8's).

Tim

[ryan.hess]

FYI- AEM, Autronic, Motec, Big Stuff 3, and many other GOOD aftermarket ECU's have all of those features and more. Most of the ECU's aimed at V8's (Holley, Accel, older FAST systems, older Haltech and older Electromotive) are very poor engine controllers and lack any sophistication whatsoever.

Thanks for the info. I guess it's unfair to group the "good" aftermarket ECMs with the "cheap" aftermarket ECMs. I'm guessing yours cost somewhere in the $2500 range?

[timg]

IIRC, it was under $1500 including WBO2. The AEM has a LOT of inputs, outputs, excellent software, and great features, but it can't control every automatic (it will do some) and it may not have as accurate ignition and fuel control hardware as Motec and Autronic have. For the price, it's still fantastic though. Chosing an aftermarket computer seems to be a crapshoot. There are some great ones out there and some that are less than stellar. Price usually won't let you know which is which. These companies have deliberately made it very hard to weed out the marketing from the facts (dyno manufacturers are the same way).

Tim

[Manitcor]

I completly agree, as someone who use to tune Allen Bradley PLCs for Turbine Generators at powerplants I can say without a doubt alot more goes into tuning than just a table of numbers. Theres multiple conditions that have to be checked for and acted upon based on inputs.

From what ive seen of most aftermarket systems thier support for artribary analog or digital inputs/outputs is weak at best and further you are stuck with writing alot of your own code and having a very deep understanding of the partcular engine you are working with.

When working with a stock PCM most of those conditions have already been coded in and the right inputs/outputs are handled and you are left to the "easy" which is adjusting the variables. Playing with logic is nto something a tuner should have todo and thanks to most ODBII tuning setups you rarly have too.