Fuel Economy

[h20-50]

Read post #22, it explains why it cannot stay in V4 mode for over 7 min.

 

I would re-read that post again. No where did it say that was the reason or emplied it.

 

But say for instance that is the case and you can only drive 7 minutes max in V4 mode. Who has ever drove longer than a minute in V4 mode before it switches to V8????? I know I haven't, prob lucky if I've ever hit 30 secs! My point was that while the truck is in V4 that you can program for a better AFR and possibly spark delivery etc to increase V4 power which enables it to stay longer. It can still switch at 7 minutes and switch back, but you effectively extended the operating range of V4.

[Range Technology]

A couple comments. GM does exactly what you're talking about. In v4 the spark map and fuel map are adjusted for that mode. The seven minute statement (which isn't a hard and fast number by the way. Different stock strategies vary that number quite a bit over the years) is to allow for thermal equalization across the cylinders and to help prevent oil aeration. The aberration was a bigger problem in the first generation AFM and there was actually a TSB I believe for adding oil shields in the valve covers.

 

Our module will keep it in v4 a lot longer than stock does without overriding any safety timeouts and while in v4 the AFR and spark are optimized.

[h20-50]

A couple comments. GM does exactly what you're talking about. In v4 the spark map and fuel map are adjusted for that mode. The seven minute statement (which isn't a hard and fast number by the way. Different stock strategies vary that number quite a bit over the years) is to allow for thermal equalization across the cylinders and to help prevent oil aeration. The aberration was a bigger problem in the first generation AFM and there was actually a TSB I believe for adding oil shields in the valve covers.

 

Our module will keep it in v4 a lot longer than stock does without overriding any safety timeouts and while in v4 the AFR and spark are optimized.

 

Ok I'm pretty sure I see how you extended the operating range. Do you know the resolution of these sensors for the AFM by any chance??

 

 

[Range Technology]

Not sure I understand the question ... which sensors?

 

The stock ECU uses the standard sensors (MAP, TPS, O2 sensor, knock sensors, MAF, cat temp, speed, RPM, etc.) to input to the strategy calculations to come up with things like spark advance, load, fuel mass/cyl (and air mass/cyl), AFR (based on O2 periodicity), calc crank acceleration, and a HOST of other stuff to optimize fuel and spark delivery. There's really nothing unique to the stock AFM sensor-wise other than an indication of "ON/OFF" of the individual cylinder lifters/coil/injector. Those all have some diagnostic input so you can see if a solenoid failed (and in what manner it is "failed"). All the magic is in the ECU engine model in the strategy/OS.

 

This occurs dynamically regardless which mode the engine is in, although when it does switch mode there's also a change in strategy to optimize for the cylinders turning on and off. It's really cool to see it all work together ... some pretty awesome real-time physics! Our module does a strategy in a similar manner to interact with the AFM to alter the behavior .. it does NOT alter any sensor inputs.

[h20-50]

Not sure I understand the question ... which sensors?

 

The stock ECU uses the standard sensors (MAP, TPS, O2 sensor, knock sensors, MAF, cat temp, speed, RPM, etc.) to input to the strategy calculations to come up with things like spark advance, load, fuel mass/cyl (and air mass/cyl), AFR (based on O2 periodicity), calc crank acceleration, and a HOST of other stuff to optimize fuel and spark delivery. There's really nothing unique to the stock AFM sensor-wise other than an indication of "ON/OFF" of the individual cylinder lifters/coil/injector. Those all have some diagnostic input so you can see if a solenoid failed (and in what manner it is "failed"). All the magic is in the ECU engine model in the strategy/OS.

 

This occurs dynamically regardless which mode the engine is in, although when it does switch mode there's also a change in strategy to optimize for the cylinders turning on and off. It's really cool to see it all work together ... some pretty awesome real-time physics! Our module does a strategy in a similar manner to interact with the AFM to alter the behavior .. it does NOT alter any sensor inputs.

 

I understand all of that, I was wondering if you knew the resoltion of the TPS and MAF sensors in particular. Resolution in bits specifically.

[Zane]

Project Sierra now has a Range installed.. here's our initial thoughts. More updates to come.