The EMS actually does have a lot of safety features. It also has a faster reaction to the knock sensor than even the stock ECU does. I've spent the last few months playing around with the EMS and it's pretty amazing how many safety features can be used at the same time if you enable them.

My friend recently had problems with his MBC and spiked to 35 psi and generated a 4 volt knock readout and it pulled a lot of timing immediately, saving his engine. The EMS also uses boost comp that adjust fuel according to the amount of boost present and keeps the EMS as efficient as you want it.

I'm not discounting the stock ECU at all...its actually pretty amazing itself. The EMS in my opinion is every hardcore tuners dream, that's all.

As a side note though, I find it hard to beleive that the Xede posts comparable numbers to the EMS with a similar tune...most users remove the MAF when using the EMS, converting to speed density. On a car i recently worked on, removing the MAF yielded almost 30 whp.

 

That's the difference. It reacts. It doesn't anticipate like the factory ECU/XEDE combo. It's far better to prevent detonation in the first place than to react to it after it already starts.

Shiv

 

How can you anticipate detonation? I'm just wondering. Does the ECU figure that if you run x amount of fuel with x amount of air at a certain inlet temp its gonna knock? I didnt know that was possible.

 

It anticipates knock by constantly updating a short term ignition advance multiplier (for lack of a better term). It looks at historic knock activity and "slides" between the two ignition tables and two fuel tables. This is the factory's approach to designing a single ECU that will safely adapt to the octane, temp, etc,. altitude variations that the car will see during its lifespan. Such adaptability has yet to be seen on any consumer aftermarket EFI system, AFAIK.

shiv on nick's computer

 

That gain wasn't from removing the MAF. The effective ID of that MAF is more than capable of supporting over 500hp worth of airflow. Don't believe me, plumb a vacuum gauge in the stock plastic intake. You can use the little nipple used for the boost control signal return line. Measure max vacuum with and without the MAF installed. What you are measuring is inlet restriction which you are claiming is significant with the MAF in place. You will be hard pressed to find measurable difference in either set-up.

Shiv

 

Shiv and I in total agreement !!!!!!

I have seen many people with stand alone systems with serious probelms getting them to run as expected.

Most people don't realize the tuning time needed to properly configure a stand alone system and the inherant trade offs that come along with running a stand alone.

Its like watching some guy with a 4 x 4 jacked up 10 feet higher than stock - sure it goes over logs and cars with ease - but now your handling is shot and you have mega tire noise and a rough ride - its part of the trade off.

The stock ecu is very hard to beat. Not only does it provide very good driveability and driving manners - its super consistant and reliable. 95% of the blown engines I hear of are running some form of end user tunable ecu system.

 

Shiv, you forgot the most important part of my quote regarding the EMS. Yes, I blew my engine, and no it wasn't because of the EMS.

Now, if your tuner is incompetent and/or doesn't spend enough time (or you don't spend enough money) your drivability and safety margin could be lacking.

The idea is to tune the car - no matter what the platform your tuning it with - that it should never have knock (minus race gas drag racers). If you tell the tuner what your going to do with the car, they should be competent enough to tune it so it will do whatever you ask it to do without blowing up. And the knock control feature is much more robust on the AEM.

Honestly, I wouldn't buy the EMS unless you plan on getting the last 10th out of your stock turbo or using an aftermarket turbo. It's just not worth the expense. But to argue that it's not a better platform is just non-sense.

 

I usually adjust my AEM on each and every pass down the track.

Or course you can always de-tune the stand alone to provide a huge margin of saftey, but that kind of defeats the purpose

I have found that a properly tuned and configured AEM set up with a good margin of saftey will make similar power to a reflashed ecu.

From my experience most of the gains on stand alones that I have seen are the reult of running a/f and ign timing settings which are both too agressive for a street driven pump gas vehilce and also which the stock ecu would not allow (though knock protection)

 

Al good Analogy, but it's so true. You have these guys that buy an AEM right away and then end up selling it FAST and loose ALOT of money in the process.

 

Sure it is...

 

Except with a reflashed ECU, due to scaling restrictions, you cannot map for more than 24psi without compromising the mapping at lower boost pressures. I think that is a big issue when almost all of the people buying the EMS are running, or are planning to run, big turbo set-ups. Reflashes alone aren't adequate for such high hp applications, IMHO.

Shiv

 

I agree 100% - properly tuned and set with conservative rational timing and a/f numbers my customers with AEM will never see any knock action beyond normal engine back ground noise unless they happen to get a particularly bad load of gas

The problem it seems to me is that many of these AEM systems are set up on inertia dynos like Dyno Jet during rushed sesions tuning in one gear. IMHO proper ecu tuning requires extensive data logging and testing under a wide range of vehicle operating conditions and loading to verify that knock is absent

Finally - I STILL can not believe it when I come accross AEM ecu's with the knock control turned off

 

Nick: www.aempower.com log on the forum and download the software. (Although it helps if your tuner turns it on )

 

This is Shiv, not Nick. And perhaps you'd like to read the rest of the thread regarding reactive and pro-active knock control.

Shiv

 

99.99% of users operating reflahes are maintaining boost levels under 24 psi - particularly those who are mapped for pump gas.

Also - with the big turbos - we have had no problems tuning to 521 whp with our flash technology. Through a lot of experince and trial and error we have found new functions within the ecu which enable us to achieve excelent results on larger turbos - For example member evodave who drives his 3037 equipped Dyno Flash car every day and went 11.5 on a pump gas custom Dyno Flash