Those with electronic boost controllers: warning!

[adamk]

Hummm,  Im probaly wrong because I dont know what im on about but....
 
Cold air is more dence so you can squeeze more fuel/oxygen into a set volume of air making for a better burn. Remember there is a lot of moisture in the air as well this time of year!
Is this the reason for the increased boost? as the car is running more efficently the exhaust pressures increase causing a knock on effect to boost ? and lack of fuel to cope with this = pinking
I know with water injection is added (the same same effect) you need to increase fueling or pinking/knocking will take place! or like you say retard the ignition.
(Are there no pinking/knock sensory or the RX7?)
It effectively makes the air more dence and cool therfore more fuel is required to match. Or pop.:eek
I can sort of understand about the fuel, But I have never noticed an increase in boost pressures due to adding water injection or driving on a cold moist day? however you will always find any car will drive lovely in these conditions due to the increased burn efficiency.
 
Rah rah rah
Any ideas  :Hammer :Hammer

[adamk]

Does the ECU anticipate and adjust fueling very very quickly using the AFR to prevent knock?
 
I dont know? Its the only way I can think how!

[BlitzBoy]

Hummm,  Im probaly wrong because I dont know what im on about but....
 
I know with water injection is added (the same same effect) you need to increase fueling or pinking/knocking will take place! or like you say retard the ignition.

Rah rah rah
Any ideas  :Hammer :Hammer

Not true you do NOT add more fuel if you have Water injection.
When you add WI it lowers combustion temps hence lowers knock.
I actually found that AFRs got richer when WI is activated.

The fact of the matter is stock and Apexi ECUs have a temp correction map so compensates for lower temps and adds more fuel.

The only reason for boost spiking in the original post is the boost controller has not self learned or the gain control needs adjusting therefore to control the wastegate accurately to prevent spikes.

A stock Twinturbo FD on stock ECU will not overboost if working correctly.
The only cars that will overboost are ones with aftermarket controllers if the gain is not set correctly therefore spiking will occur, the engine will only go pop is the higher range of boost cells of the Apexi ECU have not been mapped correctly therefore the temp correction table will have no chance in adding all the extra fuel required if the normal fuel map is not mapped accordingly(if the fuel system is up to the job in supplying extra fuel)

how it makes sense guys

[nikp]

Cheers Mark, much appreciated for the reply. So i need to turn my gain down, right?

[BlitzBoy]

yep try 5% at first Nik

[shaunwil]

Which boost controller do you own ?

Shaun

[adamk]

Told you I didnt know what I was on about!!!!:rollin
 
Clears things up mate thanks.

[nikp]

Greddy Profec B Type 2 or whatever it\'s called!

[shaunwil]

You probably have the set too high. It needs to start at a lower level so it doesn\'t jump past the level you want. What are you running turbo wise ?

Shaun

[BlitzBoy]

You probably have the set too high. It needs to start at a lower level so it doesn\'t jump past the level you want. What are you running turbo wise ?

Shaun

exactly Shaun
I have the same controller when setting the controller I started with 0 percent then slowly adjusted it higher. The gain controls how fast the wastegate closes and opens. If it stays shut for too long spool time of the turbo is quicker but there is a big chance it will spike above target boost before the wastegate starts to open and vent to reach target boost

[Smifta]

As has already been alluded to: The both ECU\'s (stock and PFC) do AIT and coolant temp correction, so should not underfuel in cooler weather.

The stock ECU does also retard ignition if it detects knock, but the knock sensor itself is notoriously crap, so rely on that at your peril!