I think the big issue with any standalone EMS is really only the fact that it won't pass an OBD-II inspection, which is something that is becoming more prevalant.. Its mainly because most cars that have an EMS,aren't easy to swap from an ECU to the EMS, and back, without major "PITA Issues" to get the car running well enough to make it through any sort of inspection.. I'm sure in time, there will be an EMS, or an addon module that offers OBD-II output for an EMS, this is the only reason that I haven't swapped over to some sort of standalone (aside from the amazing features of the UTEC itself)

I'm really curious about the PSI-FI piggyback since they only show it for the SRT-4 on their website, but I suspect its similar to most of the other piggybacks out there and therefore if they do the job that you need for your purpose, then its fine.

The one thing piggybacks traditionally have not been able to overcome are MAF cut / Boost cut/ RPM limiter issues, at least not without risky signal clamping. AFAIK the UTEC is the only unit that takes over for the ECU in open loop mode therefore eliminating any cut issue you'd get. the PSI-FI doesn't say whether or not it alters the sensor data for MAF and Crank, or it takes over for it.. But it does have some interesting features that warrant closer investigation.

The biggest problem with a standalone EMS isn't the unit, but the tuner.. The hardest thing to do with tuning a standalone isn't making peak numbers, but getting the car to be drivable and accomodate variations in weather, cold start, even running A/C, take time and are more difficult. You will spend quite a bit of time getting everything "right" if you want it to "Drive like stock". Its certainly possible, but definitely something left to someone pretty experienced in the unit since you'll spend quite a bit of time learning the unit, then adjusting it. Adjustability is what you get with an EMS, the tradeoff is compromises you make in the time it takes to get the car running "just right".

For myself, I'd definitely run an EMS if I had the time to tweak it every time I found a new quirk, or on a very cold day, can't get it to idle for sh*t because the settings are a bit off because its the first time I have experienced a day "That cold" or hot... Or the compensation needed to make because of the hot summer day where your stuck in traffic and the coolant temp and intake temp are higher than normal.. Most of this stuff a tuner can do, and if they've done enough maps, already has a base map that has all of this stuff set close, only the dyno tuning needs. This is regardless of speed density or using the stock MAF, which is another discussion in itself.

If you want the car to pass an inspection, and you cannot swap ECU's or find a way around the OBD-II check, then you really can't use standalone ECU..... Also, piggyback systems allow the factory ECU do the mundane things that take time to get working right, the exception is idle control, piggybacks do not yet have the capability to do a very good job of that, so your left with signal clamps and throttlebody tricks.

There is no perfect solution, you just have to seriously look at yourself and consider what compromises your willing to make, your time, and your intended purpose for the car really will have a huge impact on your ultimate decision.. That is until a product comes out that functions like a standalone, allows you to choose your sensor data and how it works, has OBD-II Compliant data port, and can run with a wideband and individual knock transducers for each cylinder (attached as the washer on a spark plug for instance) so the engine can run completely closed loop all the time...

What I'd like to see is how the DSMLink ECU has been adapted to the Evo (plug and play harness or jump harness) I'd certainly use that instead, because its the ONLY tunable product right now that has standalone features and OBD-II compliance. Or wait on an EVOLink ECU (which will likely never happen)

Whoever it was who did the DSMLink ECU in an evo, *PLEASE* contact me, I'm interested in how you did it. (I have an idea, but I'd be interested in trying it myself)

 

Well said

 

Can we get some more info on the SAFCII?

For those of us wanting to tune for intake and exhaust, would this be a good way to go?

 

Sadly, The S-AFC is one of those "Crutch" or Old-School type of mods, it works pretty well, but tuning is more than just putting on the S-AFC, so there is additional expense in dyno tuning, wideband O2 sensor, instrumentation, etc..

The best way to utilize an S-AFC is to use it in addition to a reflash, therefore you can tune for variations or new mods until it can be reflashed again for those mods, or you can utilize a more aggressive race gas tune. It can be used as your sole tuning device, but the money you save, will end up being spent elsewhere. If you require something that simple to work with, and if you don't intend to alter your settings once their done, consider a reflash.

I'm going to make a generalization about the S-AFC, It seems that the S-AFC is a mod that almost everyone replaces at some point in their upgrade path. In my case, there were no alternatives at the time when so I had no options. But most of you now have plenty of options, and before you spend money you'll likely never recoup, consider your other options and their prices, and see if your better off saving that money towards a more suitable engine management system.

Consider the S-AFC a supplimental system for a reflash, or a unit used for vehicles that don't have any alternatives, or any alternative is too complex or expensive.

FWIW, an S-AFC can be made to work very well, but you are still governed by the limitations of the factory ECU, just as many other piggybacks are. Tuning with an S-AFC, is however, one of the safer ways to experiment, but be aware that you can still do damage if you go gung-ho tune crazy and push it too far.

 

dave, will the aem pass inspection? if not, is there any easy way to make it pass?

 

AFAIK, any vehicle that originally possessed OBDII must retain OBDII to pass an inspection. The question is if the inspectors actually check this or not, the chances of which varies with locale.

 

If its part of the inspection process then it has to be checked for the "inspection computer" to pass the car. In NY State, our car would be OBD-II checked, and visual checked (safety and equipment I guess) but its not put on a dyno (AWD can't really be anyway) and not sniffer checked.. (Not sure if as the car gets older they begin to put it on the sniffer)

But what I was told is the OBD-II check must be done for it to pass, and if you have a CEL that goes on when the key is switched it will fail, it also has to pass the startup tests the ECU does (Catalyst check, EGR and something else)

I'm going from memory from a friend who does local inspections so I may be slightly off.. But this is somewhat what I recall.

 

I think with tuning and a cat you could get it to pass a tailpipe test. Problem is the OBD2 port, if they use that you will fail.

David Buschur
www.buschurracing.com