Start of Injection Delay

[GTS]

Quote:
Originally Posted by 907dave
Way off topic but what would be the point of increasing the MFD map to over 100 at WOT? To me, it appears to be an easy way to indirectly increase the injector pulse width above and beyond what is commanded in the multiplier map. For instance, if your max MFD is 100 and it gets you a certain PW at a certain RPM/ICP, then increasing the MFD to 110 or higher will allow the PCM to calculate (using RPM/ICP) what the new, higher pulse width should be. It's a way to get the popping and stuttering that you hear in a lot of sled pulling videos too.

What do these numbers actually represent? The MFD map represents mg/stroke per injection event. It's a direct quantity.




OK so this brings up a question or two. So you say the MFD map represents actual MG/Stroke. We all know that that can vary hugely depending on the injector and nozzle. I always assumed being it seems like this is a 0-100 scale that it was more of a percentage scale 100 being max MFD. So what is the max MFD that is recognized? I noticed when running AE on my current tunes I was only hitting a max of about 80 MFD. I was going to start by modifying the MFD to come in to 100 at the max TPP voltage that I’m seeing. But if the scale goes above 100 how far could or should a guy go with it? Or does it really continue to ask for more fuel past 100?

[cleatus12r]

Originally Posted by GTS

OK so this brings up a question or two. So you say the MFD map represents actual MG/Stroke. We all know that that can vary hugely depending on the injector and nozzle. I always assumed being it seems like this is a 0-100 scale that it was more of a percentage scale 100 being max MFD. So what is the max MFD that is recognized? I noticed when running AE on my current tunes I was only hitting a max of about 80 MFD. I was going to start by modifying the MFD to come in to 100 at the max TPP voltage that I’m seeing. But if the scale goes above 100 how far could or should a guy go with it? Or does it really continue to ask for more fuel past 100?

Concerning your part in bold and red:

Look at your low boost fuel map (it may have been renamed something like "fuel limit for boost" in your definition). That map is an actual MFD limiter.

[GTS]

Low boost fuel map is maxed out at 100 across the entire map as well is the same map for altitude. I guess if this map is a "limiter" then that would kind of answer my other questions about 100 being the top of the MFD scale. So that being said It would appear that increasing the MFD on the other maps as mentioned above would not do anything as it's being limited to 100 on this map unless you raised it higher on this map as well. I guess the question still stands though that if you incrase MFD above 100 does the PCM recognize that and will it actually ask for more fuel?

[cleatus12r]

This was before I looked at the type of truck you were driving.....there are parameters that dictate maximum MFD as well.

[GTS]

OK so my MFD in the parameters is set to 100. This brings up another question. If you have something set in the parameters such as the MFD, will that show up on the maps? So if you have MFD set at 80 will the maps limit at 80? Or will the maps go to what ever value you set them at and stay there but the parameter will just override it once the program is in the truck?