PFC Boost Controller

[GunMetalR33]

I am sorry if this has been covered before but i did a search and couldn't find this particular question.

Anyway,

There are 4 setting on the pfc boost controller: I assume from searching this forum that they are nothing more than 4 in individual settings that can be used. My question is what does the 255 mean on the right of the display. Others have said that it might be value of allowed over boost and that it cannot be changed unless you have the software.

Well 2 of my settings have changed to 200 instead of 255 and my tuner does not have the software. Does anybody know for sure what the 255 means? and does the pfc boost controller have any special features that I dont know about.

It seems that no body really knows much about this boost controller, or maybe there is nothing to know and it is a simple as it appears...

Any help would be great...

[JasonO]

APEXi describe the value your after as a 'Learning Value', and it's normal to see it change as the boost controller adjusts it's own parameters to fine tune the solenoid.

If the duty cycle is accurately set, then the learning value should change a litle over time, maybe to about 200. If the duty cycle is way off the mark, then the learning value will either be way low, say less than 50, or not reduce at all. In which case you could make some adjustment to the duty cycle to have better boost control.

[GunMetalR33]

Thanks JasonO, that make a lot of sence and makes me feel better

What about the 4 different setting that you can choose from?

[JasonO]

Set them up as you like, my personal preferance is to set 1&2, to my preferred low boost setting, and 3&4 high.

Then I set 1&3 with very conservative duty cycles and 2&4 with aggresive duty cycles.

This gives me plenty of choices.......

1 = Progressive (smooth) low boost, for poor weather, normal running.

2 = Agressive (On/Off) low boost, for good weather, normal running.

3 = Progressive high boost, for poor weather, spirited running.

4 = Agressive high boost, for good weather, spirited running.

The best way to determine the correct duty cycle is through experimentation.

Set the desired boost level, and a mid range duty cycle, then do a power run.

Check to see if you made the target boost.

If not add more duty cycle.

If yes remove duty cycle.

Do another power run to confirm.

When the duty cycle is about correct, you will make the desired boost level, with minimal over spiking.

When you have determined the minimal duty cycle for your desired boost level, this will be your Progressive setting.

Adjusting the duty cycle beyond this minimal point will bring boost on quicker, but with some spiking, a few percent more can make a big difference here and this is where the learning value comes into it's own. When boost spikes over the desired level, the learning value is adjusted, and after some time driving on this setting the ECU will learn to boost quickly with minmal spiking.

[GunMetalR33]

JasonO: Thanks mate, thats just what I needed...

[JasonO]

Oh, Just to ad some confusion.......

When I say add duty cycle, it may be that your particular setup needs to remove duty cycle.

You'll get the idea though, and you can work it out by inputing a maximum (90% ?) duty cycle, then a minimum (20% ?)duty cycle and doing the power run thing. One of them will over boost like mad, the other won't reach the target boost.

Sorry, but it is after 6am and I'm kinda tired