My PFC is tuned for injector maps and other stuff, but I don't understand how to tune the boost. I want around 13 psi on my car, and my car is running sequential stock twin. I know the second coloumn is the boost amount in bars (I'm setting it .9 in primary, and .85 in the secondary), but what is the third column. What doesn't those number in percentage mean? How should I tune them to give the best response and power?

 

And how come it seems there are 2 setting on it. I meant I'm only touching the first 2 lines, what do the 3rd and 4th lines do?

 

The % number represents the duty cycle setting of the wastegate solenoid. Basically that is the primary method of changing the boost. The other number is the target boost value the ecu shoots for. It is kg/cm^2 not BAR. 1 kg/cm^2 =14.22psi and 1 bar=14.8psi.
Some people say the target value has no effect on the boost curve, but Eric in Apexi's tech department said that is not true.

In any event the ECU will cut fuel if boost exceeds the target number by a certain amount. Going from memory I believe it is .25kg/cm^2. This is not the best thing for the motor, so if you change your duty cycle settings you should also change the target boost value as well.

 

You can configure it to run two different levels of boost and toggle between them by simply highlighting 1. or 2.

 

im bumping this back up.... i have a question... Since there are two settings... You can put one setting with low boost(as low as you can go with the settings) and the other setting with high boost. If you change the boost... will it also calibrate the rest of the FC to comply with that boost setting? because i mean... same fuel injector duty cycle with high boost... then switching to low boost for daily driver... rich as hell?

 

The boost setting won't affect your fuel ratios, PER SAY. Inside the PFC there are 20x20 maps, corresponding to boost and RPM. As you increase boost, you move to a different cell on the map, thus adding fuel for the extra boost. HOWEVER, I'm not saying you can just set the boost to be anything you want. There's other implications to increasing boost so it's always good to make sure the fuel ratios are ok using a wideband.

 

Actually, I just thought of something you might have meant. Normally, true tuning is done on a cell-by-cell basis. If you're talking about tuning by making broad injector percentage changes, you might mess up all the rest of your maps if you change them based on a high boost setting AFR. My recommendation is to read up on the subject before screwing with your fuel of boost. Tons of tuning info is in this forum. No sense in learning the hard way...

 

no no thats not what i meant... I was just asking a question... since you CAN change your boost, WOULDNT it MESS your car up snice the afr's will be the same. But you kinda answered my question i guess... So you're saying that as we change the boost and the percentage of the wastegate soleniod in the boost setting... ALLL the other settings... will comply and configure to the boost you run? MY main question was... If i run the lowest setting on the PFC for daily driver with setting 1, will it be safe to switch it to setting 2 being higher boost 14 or 15 psi?

 

OK, I see what you're saying. Unfortunately there's not a good answer. If you turn up the boost, the PFC _will_ add more fuel for you, based on the fuel maps loaded in it. However, I can't say it would be "safe" for you to do that, since a lot of other things come into play, such as whether those maps are appropriate for your car, whether your injectors/fuel pump are big enough to handle the extra fuel demands, whether the turbos have enough life in them to handle it, etc. General rule of thumb is that the PFC is rich under high boost, but of course turning up the boost has to be done at your own risk... To be absolutely safe, you'll want to do it while connected to a wideband so that you can verify that you're not going lean anywhere. And don't do it if you can't afford to fix what breaks.

 

haha i know what you mean when you say to be able to afford what breaks. Well i have a Walbro pump and kit sitting on my workbench just waiting to be installed. I might get a FPR soon too. Well i'll lay off the boost raising till i get DP, MP and cutout. Cause thats when i'll go get tuned and ill raise the boost and add my pump also. Well then im just gonna run low boost... and then leave the other setting at pri. .80 and sec. .90.

But since were on the subject... how do you know what percentage to put for the wastegate solenoid cycle if you change boost?

 

bump

 

If i have a boost controller, Do i have to mess with that Boost Section? Isn't that just like a boost controller that will controll boost if you still have stock Wastegate and Pre-control sollenoids? I have a Profec B and was just wandering about this.

Amel

 

Anyone?

 

if you use that boost controller youll have to configure the wastegate cycle settings on the PFC. I believe thats what you have to do. Also if you exceed a certain boost level your exhaust temp. light will come on letting you know that your exceeded monitering levels of the PFC.

 

But Profec already has that that **** that conifgures wastegate, weather to come on too mild or sharp. Isn't that setting on a pfc just like a built in boost controller?

Amel

 

If you're using an external boost controller like a Profec B (that's what i have), then you won't use the boost section of the PFC. You'll just want to make sure the values are turned up high enough that you don't get fuel cut from it sensing overboost.

Also, the exhaust light will never light up with the PFC. That was an intended feature that just didn't work out for some reason.

 

Thats what i meant.... but i have never experience an exhaust light coming on so i cant agree or disagree with it never lighting up. So what happens if a problem occurs? Normal CEL comes on?

 

Bumping this.. If the CEL comes on and you're using the pfc doesn't that mean you are detonating? I thought i read that somewhere.

 

It's supposed to mean that according to the PFC book, but that function doesn't work on the RX7 for whatever reason...

 

yyyeeaaahhhh