An Xede or any other piggyback computer won't do anything to help your closed loop milage. The ECU is in total control of closed loop fuel delivery.

 

FWIW: Works is apparently going to start offering ECU upgrades with BOOST control as well, starting in a few weeks. I believe mid-October was the date I heard. You might hit their site and email them for more precise details of when it becomes available and pricing.

 

Correct. If you never go on boost, your EVO's mpg will not change with the XEDE. But since boost is a regular part of daily driving, your gas mileage will improve with the XEDE, all other things held equal.

Shiv

 

Is that so? What's their website?

 

Just because there is boost in the intake manifold doesn't mean that you will switch out of closed loop mode. The ECU will switch out of closed loop when the RPMs get to a certain threshold, the airflow crosses a certain threshold, or the throttle postition gets a large positive delta input. If you are just putting around town in 4th gear at a low RPM and get 5psi of boost, the ECU will probably keep the control loop closed.

The amount of time you spend in open loop mode is tiny compared to the amount of time spent in closed loop when you are daily driving. I've never once seen a tangible gas milage improvement from tweaking my open loop fuel settings. And if you are tweaking your open loop fuel settings PURELY to get better gas milage, you are going about things all wrong. Not that I think that you are doing this, Shiv, but it is a common misconception about leaning out your fuel maps.

 

The EVO switches to open loop very easily, unlike the WRX which has to wait for nearly 60% TPS under 4000rpm. Typically, anything over 4-5psi will send the EVO into open loop fuel control. This is one reason the EVO has been much easier to tune through piggy-backs than the WRX which requires a TPS input to modify just like MAF.

shiv

 

I thought open loop only happens at WOT?
(maybe only for BMWs... i'm no tuner.. )

 

On naturally aspirated cars, this often holds true. On turbo cars, which can see full (or close to full) load at partial throttle, the open/closed loop switchover point is much lower. Or in the case of the WRX, boost is limited to 6-7psi until TPS goes above 60%. This is not the case in the EVO which sees full boost at much lower throttle angles.

Cheers,
shiv

 

Here's a bit of a OT question (I'm hijacking my own thread here)...

shiv,

I know that XEDE also provides data logging capability... I'm
wondering is there a gauge system that could work by directly
into XEDE??

Also, has there been a "Vishnu Dyno Day" in socal yet?

Thanks,

 

http://www.worksrally.com/

 

damn I got 340 miles on a full tank of 93.all but 40 was highway.