Hi David,

Sorry for the delayed response everyone. Trying to keep up with the world. Ha ha, what a challenge.

anyway, I agree with some of your statements, in regards to being able to run consistent back to back runs that can be done with almost any system except the EcuTeK. In the time I have been around (man I just made myself feel old, ha ha) I have been able to get multiple back to back runs on UTEC, E-Manage, Link Plus, WRXLink, XEDE, AEM, AFC-II, etc... what does that data really show? I would say that shows the car is good for that dyno in those particular conditions. Now as time moves on and the car has been running for a few weeks, I have noticed with all these systems, that the tune is not as good as the first day. When tested again all the cars will either make less power, less torque, or not drive as well as the first day they were tuned. My usual response to that is reset the ECU (for UTEC, Xede, E-Manage, AFC-II, piggyback systems). I would say on most of those tunes resetting the ECU usually fixes the problems they are having. Why would that be the case?

Well like you said the Xede can intercept (I think passthrough processing means the same thing, can you clear that up for me) the signal and adjusts it accordingly. Now does the Xede only delay the timing signal so that timing can be reduced? Or does the Xede also advance the timing? If so how does that work, I have not tuned enough to know yet? I know the E-Manage system was designed to only delay the signal to the ECU, so this works decently with NA cars with Turbo's but for OEM Turbo cars this is not the greatest system. Now as for the Xede, UTEC, E-Manage, AFC-II, all these systems still rely on the stock ECU, in other words a piggyback system. In turn the stock ECU is waiting for a signal back from the engine sensors. It sent out a value and returns a value, simple computer programming. If the value is within spec (but off target) the ECU will make minor adjustments to meet the values defined in the maps. This type of tuning on the car will result in a car that can tune itself from day to day, daily driver, to weekend racer, to full blown racer.

Now since all these systems intercept signals, adjust signals, etc... The ECU is still looking for a return value, and the farther it is off the more the ECU tries to adjust back to the required range (spec, if the signal is far out of spec) or the defined value within the ECU (less far out of spec). The UTEC intercepts outgoing and incoming signals, like the Xede (David or Shiv could you help me out with that part, how does the Xede treat signals from the sensors, does it adjust them back to the ECU or not), and adjusts them to closers specs for the stock ECU. Though these signals are still off the target they are close. So the tunes are held for a longer period of time, though if you look at this over a long period of time the piggyback systems will eventually fail, as the signal processing (manipulation of signals) can only be so good to accomodate the stock ECU. The piggyback and ECU will slowly grow apart from each other, eventually leading to hesitations, possible detonation, etc… Though if you knew exactly how the stock ECU works, every little detail (which I probably know like 10% of, very complicated), then you could create an amazing piggyback system to intercept signals and send the exact signal to the ECU that the OEM ECU is looking for. Though if you are doing that why are you using a piggyback system, shouldn't you just use the stock ECU and reflash it?

Now I never mentioned the EcuTeK and the consistency of the unit. Well I will say it is not consistent at all. In fact it is probably the least consistent of all, though this is what makes the unit so amazing. The reason this is amazing is the fact that the unit can adjust on its own if tuned correctly. Whether the car is driven hard for track use, or just daily driven the ECU adjusts those certain regions based on your driving style, techniques, etc… Though tuning these areas becomes an art in itself. A simple DeltaDash datalog will only show the top level tier of tuning, though there is so much more below the surface that needs to be tuned for performance on the track and off.

Cheers,
Bill Knose
Lead Tuner
I-Speed USA

 

Bill,

so by resetting the ECU (when used w/ a piggyback system), you close the gap that is naturally occuring between the piggy-back and the ecu?

So, if I ran a utec, can I just get in the habit of disconnecting my battery every couple of months and that will prevent the "inevitable" decay of the original tune?

side note: Bill I sent you a couple of emails. I know you're busy, but let me know if you didn't get them...this is dan w/ the VF35 bTW.

 

What isthe priceces for an Ecutek, may I ask? And how much do these tunes
generally cost?

I'm looking for a tuner as well.

Oleg

 

ECUtek with I-speed with 2 hours of tuning is $650

 

Bill,
we met at LIC. I've got the Black STi waiting to put in my SR/50. I was wondering, when will you have STi ECuTek? Also thanks for all the useful info , i learned a lot from your post.

Richard

 

I think the STi ECUTEK has already been released. And yes, I'd take it to Bill for tuning if I were you.

 

Hi guys,

In an effort to clear up a few misconceptions, here's some info on the XEDE:

The XEDE is a interceptor based engine control system (read: piggyback) that intercepts and regenerates the MAF signal (for fuel) and CAS/Crank Angle Sensor signal (for ignition timing). The MAF signal (simple 0-5 voltage) can be attenuated or augmented (for more or less fuel delivery). The CAS (not so simple +/- pulse voltage generated by an asymetric crank-mounted toothed wheel read by a magnetic pick-up) can be phase delayed as well as advanced (using some pretty trick predictive logic) for more or less spark advance. One of the neat things about the XEDE is that it, AFAIK, is the only truly transparent piggy-back system that doesn't interfer with any of the factory diagnostic systems. It is also the only, AFAIK of course, system that offers greater mapping resolution than the stock ECU.

In addition to intercepting MAF and CAS, the XEDE also intercepts and replicates TPS (throttle position signal), Boost signal (PWM % cycle) and MAP signal. More importantly, all the tweakable variables (MAF, MAP, CAS, BOOST and TPS) can be mapped with respect to user-definable load variables (you can chose between MAP, TPS, MAF) and user-definable RPM breakpoints (put 'em... up to 20 of them... wherever you need them).

The XEDE was initially designed for the WRX which, arguably, has the fussiest ECU to keep happy. As a result, much time has been put into retain EVERY SINGLE one of its unique features, right down to it's closed loop boost control. Every single advantage provided by the Subaru ECU (adaptability, knock control, etc,.) is retained. This is why the XEDE has proven to work so well with either stock or reprogrammed ECUs.

If anyone has any specific questions, fire away... I'll be happy to answer as well as I can.

Cheers,
Shiv
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Waterbongs

 

Shiv,

Thanks for the information, what you said makes sense to why the Xede holds a better tune for a longer period of time and a simple reset will fix any hesitation problems. Now, I am not sure how much Chip-Torque will divulge thier secrets, though it can't hurt to ask.

Would you be able to explain any more about the predictive logic, as this is the only piggyback system currently using predictive logic. I know on the E-Manage it does not allow for this, only retards timing, the UTEC takes full control of timing, though still could use a better implementation. Though advancing the timing based on a signal from the ECU that is not even known yet is quite interesting.

Does the predictive logic advance the timing based on a prior CAS signal, current load, MAF and TPS values, which create a timing value to be used for the next spark, before the signal is even read from the CAS?

Cheers,
Bill Knose
Lead Tuner
I-Speed USA

 

Hi Bill,
I'm not quite sure what you mean about fixing hesitations with simple resets. There should be no hesitations with the XEDE. At least no more than there are with a properly tuned factory ECU (stock or reflashed). When I tune XEDEs, the only time resetting comes into play is before tuning to erase whatever long term knock learning the car has done prior to coming to me. After this, I do what I do with our reflashes... I induce an IAM of 16 and start tuning. The rest of the tuning process is essentially identical to tuning through reflashing the ECU. I still watch and log knock corrections. The only difference is that I do it through delta dash, instead of flash2002 (although I have been known to log with it for its pretty color coordinated tables). The only reason to ever do an ECU reset is if the spark timing or fuel tables were mis-mapped too aggressively. The hesitiations, 5 out of 10 times, is the AIM dropping in leaps and bounds through the course of hard driving. 3 out of 10 times, the hesitation is caused by not having a good handle on short term fuel corrections (ie, transitioning between two load points with a -25% on one side and a +25% on the other). 2 out of 10 times, a hesitation is caused by running too much boost when the car is still in closed loop fuel control conditions. This is easily solved with the XEDE (at least in MY2002-2003 applications) by accelerating TSP input using the XEDE's 3d TPS table. Needless to say, any of these hesitation situations are mapping related and not inherent in the tuning system/hardware.

As for predictive ignition logic, I can't go too much into it for obvioius reasons but the XEDE has always had it. The function of the logic is to always know (or have a very good idea of) where the crankshaft position is at any given time. With the Suby, it's quite easy considering how many teeth it has on its trigger wheel. With the EVO, however, things got difficult since there are only 4 teeth to read off of. It's really quite funny seeing the factory computer trying to do all its ignition duties and misfire detection diagnostics with so little info. The Chiptorque boys and I spent the last 2 weeks on our dyno refining the XEDE's predicitive logic based upon what we saw with the factory EVO ECU. It's really quite impressive. That's about all I can say without giving away too much info

Cheers,
Shiv
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