OSE 12P Wastegate Control

[kojab]

I really wanted to see if I could get the flex tables in 12P to control the wastegate in my turbo charged 3SGTE powered AW11 MR2.
I found this very challenging as it was more difficult than I thought it would be.

This is the type of solenoid I am using: http://www.ebay.com.au/itm/ACDelco-GM-3 ... 0685311806 Same as found on L67 supercharged engine.

Would have displayed these images with TP but my Logger2 is away with VL400.

Please note that the Label "Vol_EFF" is the duty cycle% output of the 12P flex table at A4
Please note that the Label "Batt_VOLT" is the PWM voltage across the 3 port Solenoid monitored by B2 (0-25v)



First attempt using kPa and RPM as inputs for Flex table "A" . Yes it worked but I did not like the oscillating boost result.

1M30WG-15.png (8.19 KiB) Viewed 6626 times

Second attempt using TPS and RPM as inputs for Flex table "A". Was very happy to see this result.

2M30TWG21.png (7.78 KiB) Viewed 6626 times

The beauty of using the 3D flex table is now I can control my boost output with my throttle. Like boost on throttle command.

[festy]

This is interesting, I'm planning on having 12P control my wastegate (when I get around to finishing my turbo setup)...

Doesn't RPM vs TPS then mean you don't have a pressure input variable to the wastegate control?
Would chaining the flex tables help here, or make it worse? i.e. flex A = RPM x TPS, flex B = flex A x MAP or something like that?

[kojab]

Yes like you I thought it would be necessary to combine flex tables to introduce some form of kPA (boost) feedback control but so far this has worked very well just using a single flex table, using RPM and TPS inputs only.

In the next few days I will up the boost to 20 psi to see if it holds the same trend. I suspect under quick heavy acceleration there will be a slight over shoot of a few psi, this will not concern me providing the boost level falls to a controlled consistent boost level.

[VL400]

Looks good kojab, seems to be working well now. You got similar results to what I have found, with no proper feedback control loop it will oscillate when trying to use MAP kPa as one axis. It can be dampened with careful table setup but couldnt ever get rid of it entirely.

Festy: Its open loop boost control but it does work well once you know what sort of duty cycle is needed for a particular boost. Overboost protection is handy to keep some safety in there. One day closed loop control will be added to 11/12P!

[VX L67 Getrag]

Nice work!

That's pretty exciting with the additions to 11p/12p too!

[vlad01]

Nice work!

That's pretty exciting with the additions to 11p/12p too!

oh yeah! can't wait.

[Holden202T]

very good I have been talking with VL400 looking to do something similar in my Gemini to get more of a launch control sort of thing to stop too much boost hazing the tyres off the line, but I have yet to do much more than think about it

I assume that solenoid has 3 ports so boost reference, then one to either side of a wastegate ? looks like a good price for what I need!

[krusty]

very good I have been talking with VL400 looking to do something similar in my Gemini to get more of a launch control sort of thing to stop too much boost hazing the tyres off the line, but I have yet to do much more than think about it

I assume that solenoid has 3 ports so boost reference, then one to either side of a wastegate ? looks like a good price for what I need!

I have about 40 of these in a tub. Cover post and I'll send you some if you like mate

[Holden202T]

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