MembersPage/JanneMantyla (2007-01-16 22:59:31)

I'm Automotive Engineering student from Finland.

I were developing four-cylinder BMW M10 2.0 '77 turbo engine as my engineering/diploma work, but I have changed my work to Honda D16Z6 SOHC-VTEC All-Motor project. Reasons for this are too high costs for a student, and I definately need a new (and ofcourse better and more powerful) engine to my daily driver Civic.

Pure AlphaN, WBO2 etc now working excellently! Engine runs damn smooth in ~any conditions, EGO correction works etc.

That AlphaN is very easy and straightforward to tune.

I also tried AlphaN blending first, but that doesn't work for NA engine with ITBs, it's only meant for smoothing idle with aggressive cams. config13 bit 2 has to be enabled via keyboard or config.txt to get AlphaN working! MegaTune doesn't have an option for changing it! I had some serious problems trying to get engine working without it first (and blending enabled in MT; It just doesn't work at all). This MegaTune / AlphaN - config13 issue is fixed in newest releases, under Alpha-N/Speed-Density Blending setting, MAP(load) multiplication.


Check my MembersPage/JanneMantyla/PictureGallery ! WARNING! lots of high-quality pictures on same page! Same pics can be found under link below, see vems and d16z6 folders, I think I'll remove this.

A couple of project photos etc can be found here; http://rushi.kapsi.fi/pics/

VEMS-Related stuff (configs etc) http://rushi.kapsi.fi/vems/

Videos etc http://rushi.kapsi.fi/video/


D16Z6 Engine construction

D16Z6 sensors etc

Current firmware version; 1.0.38


Questions and answers

Q: I'm trying to drive VTEC-solenoid (it needs positive supply, and has R of 16ohms) from stepper driver IC, because it seems to be able to supply 1A. Somehow I'm not able to get it working; I use MiscOutput1 for it(S259 Q3 = stepper_A, right?). AFAIK when that is activated, output should go to +12V, but that doesn't seem to work.

  • what do you mean by "does not work" ?
  • Measure voltage
  • measure current if possible
  • try to activate with mdh.. command (disable the output during this experiment)
What should I do? I was looking for V3.2 schematics, and found S259 Q7 going for stepper enable, and added that into RPM actuator; It still doesn't work, what might be wrong? -Janne

I ment that activating S259 Q3 didn't give ~Vbatt or anything else into it's output pin. I was correct, that IC needs to be enabled separately (S259 Q7).

Now it works perfect on VEMS-side, I use RPM actuation for enabling(Q7) and MiscOut1 for VTEC control. This works now just like it should, gives good drive to solenoid. I still have some problems retated to solenoid(mechanical) or oil pressure.

Q: Is there any better way to enable stepper ic, than waste rpm-actuation for it? From software, hardwiring +5V to IC would be easy too.

A: Yes there are. Because MiscOutput doesn't have CLT variable (and would be nice to have) I figured I could use waterpump drive for chip enable.


Now I've got VTEC working properly. I was considering that maybe stepper driver IC is inadequate, and made a stronger driver circuit with TIP127 PNP-Darlington transistor. I use P259 Q7 (drive_11) to active darlington (thru 330R base resistor), and also connected my CEL-light into same P259 pin to use it as a VTEC light. VTEC drive output goes to EC36 pin22 (yes, I don't have extra GND5 on it).

I still had weird behavior, and then I figured out that it works with TPS 99% and lower, but not at 100%. Then I tried to use pure RPM-actuation and it works perfect now! Later I get confirmed that this old firmware (1.0.38) has bug related to MiscOut function, and it's been fixed in around .45-.48 versions!

Actually, I think I leave it to RPM-actuation, it seems to work so well in practice. Stepper driver seems to be adequate to drive 16ohm VTEC solenoid, if there's no other use for it.