Wastegate Duty Cycle % - Perth-WRX.com

waxdass · #1 15-12-2008, 09:16 PM

the VF34/p20 is running with a AVO 1 Bar actuator.
I havnt been able to test the car on boost until today(run in) - I have been giving it a bit of a flogging and noticed that my turbo seems slower/laggier to come onto boost than last time.

I did some logging with ecuexplorer - and I noticed that upon building boost - wastegate duty % goes to a maximum of 85%.
Subsequently - It does not go over 1 bar of boost, ever.

Shouldn't I read 100% (fully shut)???

(or is it the other way around?)

Is this a management problem or Do I need to wind the wastegate tighter?

jEstEr? · #2 15-12-2008, 09:34 PM

is it currently on a run in tune or is this a final power tune?

Rossco · #3 15-12-2008, 09:38 PM

100 % duty cycle on the wastegate solenoid (fixed open) = actuator pressure ( as your avo is 1 bar that's all you'll see)

my old Rs would see 7 psi at 100% (stock 7 psi actuator) and using a profec B controller ramping bewtween 0 - 60% 16 psi from 3200 to redline.

Sounds like the tuner has taken the midrange punch out (fast boost ramp up) to be safe before final tuning.

HTH

waxdass · #4 15-12-2008, 09:49 PM

its running stock ecu atm. was running in with mineral oil for a 1000kms..

Autronic aint going in till mid/late Jan

jEstEr? · #5 15-12-2008, 09:53 PM

if its still on run in tune... just leave it?

waxdass · #6 15-12-2008, 09:55 PM

its not a run in tune.
its a stock 04 STi ecu - I have been advised to run the engine in for a 1000kms, and not go over 3k.

today i got fluids flushed and I put it on boost.

Rossco · #7 15-12-2008, 09:56 PM

Stock ECU is trying to build boost like a stock turbo does (their fixed rpm/load/ duty cycle maps from memory)......Duty mapping will be way out for your setup.

Suprised the ecu hasn't thrown a CEL yet, obvously the ecu hasn't worked out that it can't reighn in the turbo yet lol....

Do you have the restrictor (boost pill) in the air bleed back to the inlet pre turbo ?

Logic tells me that the bleed would need to be less restrictive with a stronger acutator (ie my00 sti .9 mm V my00 P1 1.5mm).

waxdass · #8 15-12-2008, 10:05 PM

Actually funny u say that, it has thrown a CEL. I thought it was because I thrashed it a bit too much.

I checked ecuexplorer - and it didnt register the CEL.

So it looks like its pureley a management problem - and not a loose gate?

Rossco · #9 15-12-2008, 10:21 PM

adjustable gate....Hmm! forgot about that..... firmly sealed with the engine off and spring pressure holding it firmly closed ??

Slow boost build-up could be through a small amount of wastegate creep (i.e enough to relieve a small of exhaust pressure).

give it one turn tighter and drive it again (sanely) and see if it improves or not.

You'll be trying to find the happy medium between w/g creep (too loose) and boost spike (too tight).

I did a T04E onto a 13b turbo in an early Rx-7 ages ago...took me a couple of hours of trial and error to get the actuator rod to the best length / best w/g preload.

The old Rs' Lib would blink the CEL on overboost (16.5 psi) if you hit over that twice the third time you'd hit the wall (boost cut), the CEL would stay lit and lower the boost cut to 7 psi until the engine was shut off and restarted.........no fun on a cold winters night

waxdass · #10 16-12-2008, 08:36 AM

OK still have this phantom CEL light on, brings up no Pxxxx error code.

I preloaded the actuator as per AVO instructions, I even had to fit a compressor to the line to open it up so I could slide the pin onto the wastegate hole.