Umm yeah. I suck at excel and dont really know how to "plug the formula". Also, I dont really have many logs to use because I used to not log the AFRnumber.

The new EVOScan was suppose to be out this weekend.

 

cool

 

still no working??

 

huh?

 

thanks for the explanation guys! I'm still trying to fully understand what all goes into controlling boost on the car. So the WGA is pneumatic, and depending on the pressure differential across the diaphragm the WG will open or close. The pill in the hose leading from the WGA to the boost solenoid slowly bleeds the pressure from one side of the WGA diaphragm as long as the boost solenoid is open. So if the solenoid is closed, the pressure on both sides of the WGA diaphragm is the same and the WG is closed, but when the solenoid opens the pressure drops which opens the WG. Do I have this right so far?

I wonder why this chain of control is so long / complex ... why not just use a solenoid to directly move the WGA as the ECU commands?

 

Rob W it is the real load value that is being logged experimentally.

voidhawk, you'd need quite a posh stepper motor and good linkages to isolate it from the heat to control a wastegate directly. There is also some intrinsic feedback with a typical pneumatic setup that leaves quite an undemanding control task.

Bleeding off air through a solenoid or solenoids as the stock system does merely prevents the acutator diaphragm seeing as much of the boost pressure. This along with the spring in the wastegate actuator keep the wastegate closed. However, note that exhaust manifold pressure can overcome the wastegate spring and open the wastegate no matter what you do with the pneumatics at high RPM/high boost, this is why it tapers if you run a lot of midrange.

 

Just to jump off topic for a second: EvoScan 0.97 was released last night/this morning!

 

hm, I may have answered my own question (partly). Apparently the reason why you want boost control proportional to load rather than just a target boost pressure level is throttle control. Since load is proportional to throttle position, that's what controls the boost solenoid and thus the WGA.

Still leaves the question of why mitsu used a pneumatic WGA rather than a electromechanical actuator - I'm guessing cost had something to do with it ...

 

I replied with my thoughts on your last question.

 

 

Hi

Came up with a similar solution myself. I used a nipple from a mountain bike break cable as a restrictor, drilled it out and pused it in to the T piece. Using the target boost to control presure.

MB

 

OK, so we both had to use a different restrictor. I tried messing with the desired boost target with the stock pill and couldnt get the boost up. It seems like the desired maxes at 159. and max offset at 100.

Can you tell me more (everything) bout your way of control. When talkin bout the target boost, you mean desired boost load target??
Also, tell me what tables you changed and more about your way of boost control.

 

Whilst the load16 scaling for boost control load offset in ECUflash is limited to 100 in the load16 def, I don't see this limit in the code. It reads the whole word from the offset address and adds it to the boost target. Even if only the lower byte is used by some later trimming (which I also haven't seen) then the least it would appear to go to is 159.

 

So what are you saying is the limit for the offset??

 

Also, I tried raising boost using desired load and load offset on a stock IX (stock pills) and it didn't make a difference in peak boost. I change the desired load to all 159s and changes the load offset from 80 to 100 and then to 120, and I didnt get more boost.