I own and am pretty familiary with the UTEC, although I've still got a long way to go. I was just curious about the XEDE, so this is the result of my quick read.

Statements in blue taken from the Vishnu website:

Additionally, XEDE users can define not only their own Load and RPM breakpoints for each map, they can also determine which Load variable to use (TPS, MAP or MAF) in order to best achieve their specific tuning goals. Simply put, no other form of engine management offers this degree of tuning flexibility

What does that mean? Ok, I know that for my fuel tuning, it's part TPS load and the rest MAP load. I don't even fully understand what that means, let alone being able to choose which one I want to use. What's so great about using MAP vs. TPS? Is it because MAP is affected by the surrounding weather conditions? How are MAP and MAF different as far as tuning? From what I understand, MAF is pretty inconsistent. TXS has even stated that they are trying to move away from using MAF as a factor.

As it stands, for fuel and timing the UTEC uses TPS for load 0% and MAP for 10%-100% load. It uses TPS throughout for boost. Seems pretty straightforward and easy to me.

One of the most innovative features of the XEDE is the ability to influence closed/open loop fuel control transitions. This is elegantly accomplished by mapping a revised throttle position signal (TPS) with respect to actual TPS and engine speed (RPM). Using this approach, it is possible to induce open-loop fuel control switchover under the conditions you see fit.

I don't feel any transitions between open and closed? Open being pretty much anywhere between 0-1000rpm and 0-60% boost (0-10 lbs). When my ECU is controlling, it's open-loop. When I'm in my map, I'm in CLB.

Compared to the Unichip, the XEDE is capable of vastly superior CAS replication. This ability greatly improves active knock correction performance, general drivability and invisibility to the factory diagnostic system. Perfect CAS replication insures that there is absolutely no misunderstandings between the factory ECU and the XEDE.

Huh? What's Crank Angle Sensor replication? Is this addressing the problem that the EMI was designed to fix. Again, I don't know if I have this problem, but as far as I know, I don't.

When I shift aggressively, when my friend Sean did, and I guess my friend Richard and many others over at wrxhackers do; a few knock indications show up. Best opinion that's been kicked around is that it's the additional noise from driving hard.

Unlike the Unichip which is capable of modifying only Ignition Timing and MAF signals with fixed load (MAP) and RPM) breakpoints (every 500RPM, the XEDE is capable of modifying Ignition Timing, MAF, TPS, MAP and Knock sensor signals with respect to RPM (up to 20 user-definable breakpoints) and any one of three Load variables (MAP, TPS or MAF).

So does the UTEC, I think.

It has Internal storage space for up to 12 tuning maps but only 'Map Select' input to change between one of two unique tuning maps

The UTEC has 5 plus 1 (valet) and can swap between any on the fly (easier with the remote switch). No big difference, here, though because I for one mainly use one, and if I switch, it's usually to only one other map.

The XEDE doesn't have knock correction. Shiv says that the OEM knock correction is the best that he's ever seen.

XEDE = $795 plus software for $100. UTEC = ~$990.

The UTEC has a built in programmable solenoid controller. It can control nitrous, water injection, intercooler water spray or any other solenoid device. I didn't see where the XEDE could do that.

I don't think that the XEDE can datalog.

My biggest gripe with the UTEC is the lack of a tuning 'handbook'. The Instructions are great; I've read them no less than 5 times and read within them countless times. I must be a rock. I know how to tune my car to be 'safe' without a dyno, but I have no earthly idea how to tune aggressively to get at that 273.8 whp @ 6047 rpm @ 17.0 psi.

Please educate or correct me as necessary.

If Nathan or anyone from TXS reads this, be advised I'm very happy with my UTEC. I just wish there was a tuning manual and everything would be fine in the world.

Pat

 

Nathan,

Thanks for the response.

Any compunction towards vacationing in Oahu? If you could pack a dyno in your luggage, that'd be great.

Pat