The RPM enabler is there to bypass the time delay conditions (of which there are a few), once the other enablers have been met (MAP, TPS). On a modified tune, this time delay is almost always removed, making the RPM condition useless.

 

HPT does not have time enablers. It has boost (2 bar+), MAP, RPM and TPS enablers.

 

Yep, they're not available, but they're still there in the tune. That is why it is essential to either set the tq enable to 0 or set the rpm bypass to 0.

 

How do you know its a stock part of the PCM and not an added feature of the actual EFI software?

 

Heres HPTs enabers:

http://img.photobucket.com/albums/v6...PEenablers.jpg

 

Because it exists in every factory LSx based PCM calibration. To get added features you have to upgrade to a custom OS (in EFILive and HPT both). EFILive and HPT both cherry pick the parameters they want to enable for their customers. There are hundreds, perhaps thousands more that are available in the PCM that we don't have, and, for the most part, don't need access to.

Examples. 2500HD 6.0L - 60 second delay, with the RPM bypass set to higher than the WOT shift point. Won't hit PE in a stock tune til a full minute of 90%+ Throttle has occured.

Stock Silverado SS - No time delay.

Stock 4.8L LR4 - 3 second delay.

98-00 5.7L OBS trucks, 2005+ trailblazers, 2005 LS2 OS, basically every stock tune that I have a copy of to check here all have a time delay parameter of some sort.

 

hummmm... I havent seen the files for those trucks. Ill se if I can DL one and see if it has a time delay. Ive never seen one on my truck or any F body. Maybe thats our "Enrichment rate".

A big time delay ike that seems pretty pointless...

 

It's an entirely different parameter not available (at least in the PE tab) in HPT. Enrichment rate is separate from the time delay. In addition, there is also a ramp in and ramp out rate which are the rates the PCM will transition from stoichiometry to the P.E. Mode Commanded Fuel.

The time delay is a CAFE (corporate average fuel economy) issue. Keeping the system in closed loop longer saves fuel, helping to raise the EPA estimated mileage to allowable levels.

 

Sound pretty stupid still though since when you go WOT, the fuel mixture needs to richen up right then and there to avoid the lean condition because of the serious rush of incoming air. Doesnt seem safe.

 

yeah but most factory stock vehicles have tons of torque management, low timing, ect ect to keep it safe anyway. It only becomes a nessecity to go rich quicker when you are modding like us.

If you look at our (HPT) enablers the RPM is even labeled as delay rpm.

The enrichment is just a "step" to get to desired afr. If you are at 14.68 and BAM command 12, and you have your enrichment set to 1 your pcm will command each afr increment of 1 until it reaches desire (or so tries depending on error).

Here's another...