52 replies to this topic

[james4563]

Is it normal that maximum pressure the actuator sees from the OEM boost controller is only about 12psi? This would mean that the wastegate would only open a few mm because my static break is 10psi. Based on putting 12psi to the actuator with a pump, it's hardly opened at that point, no where near fully, probably not even half open. Is it normal for it to open so little for CS stage 4 map? Any idea Steve?

[siztenboots]

As you can see from the pipework , the output of the compressor wheel feeds in to the 3 port solenoid , and this is pulsed to either give pressure to the actuator , or return to the input side of the compressor. Fail safe you should see all pressure go to the actuator and open the wastegate. The control of actuator movement, or duty cycle is determined by a lot of functions by the ecu.

[james4563]

Looking back at the Dyno graph that you posted a few pages back, I'm not surprised I'm getting lots of stalling. In 4th gear by 3000rpm I am making 23psi, compared to your Dyno at 3000rpm is just making 11 or 12psi. Unless the scale on the right isn't boost psi??

Edited by james4563, 06 December 2017 - 06:44 PM.

[james4563]

So I had the car data logged with a tech2 today on the Dyno. The ECU is asking for 255kpa basically as soon as you open the throttle up. Which as I understand is the max boost the ECU can ask for on a OEM map sensor. The turbo is then delivering that boost, so there is no apparent mechanical fault it's just the map. Fueling and boost control look good, it's simply the map asking for maximum boost so early. 1.5bar at 2500rpm which makes it even stranger why Courtney would tell me that's not possible. They did map it after all. Going to call them tomorrow and discuss.

[Nev]

1.5bar at 2500rpm which makes it even stranger why Courtney would tell me that's not possible. They did map it after all. Going to call them tomorrow and discuss.

 

 

Yep, the OEM MAP sensor sends a 0 to 5 volt signal based on 0 to 1.5 Bar of boost, so your info concurs with the sensor's range.

 

What "stage" is your car meant to be mapped to and what mods does it have (eg does it have a CC?).  

Edited by Nev, 21 December 2017 - 07:20 AM.

[james4563]

It's a stage4 so by nature its very aggressive. But none of the CS stage4 cars I've seen make 1.6 bar at 2400 rpm, they normally make peak boost at about 3500rpm.

[Nev]

Sounds fishy to me, if it's making that much boost so early in the RPM range probably means the engine can't consume the charge for some strange reason...

 

If the OEM could get the turbo to spool completely by 2400 RPM then they'd do it (as it would lead to better economy (ie the onset of earlier torque)), so if they can't I find it hard to understand how your car is managing it.

Edited by Nev, 22 December 2017 - 01:11 AM.

[james4563]

I can't remember if I posted this before but here are some of my dyno graphs.

 

https://drive.google...2k4VF8xZm1rNF9B

https://drive.google...TZSZ1M1M2VkV0o4

 

Peak overboost at ~2400rpm. Compared to the graph a few pages back which makes peak boost at like 3.5k RPM. Courtney said to me it depends of course on when you put your foot down, but the graph on the previous page runs from even lower RPM than mine does anyway.

 

After all the stuff I've now replaced I guess it must be the map. Regal did a bit of diagnostics and said that the ECU is asking for maximum boost (255?) as soon as you put your foot down, which I guess suggests that it is the map. It's only got a 2.5bar MAP sensor as well, which means that the ECU can only fuel for 1.5bar off boost. So seems a bit strange why it would be mapped to allow such high overboost.

 

I have emailed siztenboots regrading a remap to see if that changes anything.

 

I've not seen any CS stage 4 dynos that look like mine does. Even from the astra forums.

 

 

 

 

[Nev]

You could consider binning the OEM ECU and buying a 3rd party one and get it mapped - would give you far smoother delivery and the ability to tweak the map yourself to suit conditions. would cost a bit though.

[siztenboots]

email replied to

[siztenboots]

not sure if it was you calling , but just cut you off getting the phone out my pocket

 

/edit , no sorry it was another customer , lol

[james4563]

Does anyone know what peak boost psi I should see with actuator just set at 10psi and BCS disconnected?? Steve came over on Saturday and we put the 260 map on the car and I'm still getting about 20psi peak over boost. Should have been seeing about 16psi peak, that is with actuator set as weak as it can go to hold the wastegate shut on turbo smart 10psi actuator, e.g no preload. I was going to try running with BCS disconnected and see what peak over boost is then, I assume more than 10psi though??

[Nev]

1. Have you put a camera in the engine bay, focused it on the wastegate/actuator yet and taken it for a drive, so you can see if the wastegate is opening in the video?

 

2. Have you tried manually moving the actuator (by hand) to see if it is free to move?

 

Edited by Nev, 27 February 2018 - 05:08 PM.