NefMoto

hello all, I've been spending some time lately on getting my boost under control. I did some logs with CWMDAPP = 8, plugged it into prj's spreadsheet, and output a fairly nice KFLDRL and DIMX according to my eyes. I massaged DRL and DIMX after doing some more logs, and have it down pretty good right now according to my logs.

Anyways, I've attached a log to this post as well as my DRL and DIMX maps. I'm not sure I understand DRL and DIMX thoroughly. I understand DIMX should be your WGDC to achieve the boost at steady state, and the WGDC output runs through DRL last(please correct me if I am wrong) before getting output. I'd like some input on if I'm heading in the right direction, and maybe a explanation of the DC axis in DRL.

car is WB 1.8t with a 60trim. brand new 01 a4 MAF, 4bar MAP(no 5120 yet)





As an aside, my load/MAF looks pretty low. I'm using MLHFM from a TT225 with the appropriate housing.

Sounds like you wrote the solution to your own problem yourself, only you didn't know it :D

You need to figure out your own MAF scaling when using a sensor not originally installed in your housing. Log it in a stock housing, record the g/s at various loads/rpm and scale MLHFM until the new housing reads the same as the old one.

When using a TT housing ,shouldnt you just copy the TT MLHFM map with the axis and you are done ?The sensor inside is the same  ???

If the sensor has the SAME part number then yes, you can use the TT MLHFM.

I am fairly certain the TT and A4 MAF sensors have the same part #, but I'll check.

No input on my DRL/DIMX maps and log?

You state the answer in your first post:


But your DIMX values in steady state make no sense.   Do you really want zero wastegate DC to maintain target boost pressure?

Edit Hint: Look at your boost PID results in your log.   After spool,  lditv_w (taken from DIMX) should be the wastegate dc that will maintain your target.   When mapped correctly ldrdtv will be zero, and ldptv will be very close to zero.   Keep in mind though that the sum of those outputs (ldtvr_w) will be run through DRL to produce ldtvm.           

Broke my hand when my axles needed replacing, but my car is back up and driving so I started to get back at this. I revised my DIMX table and flashed the car. Boost control is much better as in there is no oscillation, but it overshoots a lot at first. ldrtv is 0, and ldptv is very close, as pablo said they should be.

Should I massage these tables some more? Or should I adjust the Q2 to reel in the overshoot?

Attached to this post is my revised DIMX(WGDC NEF) and accompanying log, as well as what I believe should be my final DIMX table(WGDC NEF revised). Please take a look and tell me what you think.

What about when you tune for beyond the ori MAF's limit? This is where I am confused.

This is not quite correct.
According to FR http://www.nefariousmotorsports.com/wiki/index.php/LDR_PID_controller_(LDRPID) (http://www.nefariousmotorsports.com/wiki/index.php/LDR_PID_controller_(LDRPID)):
Integral component lditv = lditv(i-1) + KFLDRQ1 (or LDRQ1ST) * lde(i-1)
KFLDIMX just limits the integral part to not to overshoot too much

Any help? Anybody have a file with DIMX/DRL tuned for external wastegates so I can try and figure out whats what?

I think its the spring tension that counts in the wastegate servo, not if or not its an external or internal wastegate.
 

+diameter

Tial 38mm, 12psi spring.

Since its a 12psi spring, am I correct in assuming my DIMX table should be 0 until 12psi or ~820mbar? Is it kosher to redefine the axis to pressures more suitable to my BT application?

After some more thinking and tweaking, I've found a DIMX/DRL combo that works well. Overshoots ~5 psi but I'm riding the MAP limit so that will hopefully get better with the 5120 eventually.

Bosch S4 MAF is in and load is where it should be. Just have to massage KFKHFM now.