Speed Density

[Th3Franz]

So I wanted to post my plans to run Speed Density on the stock ECU using NSFW's patch.

 

I have an Omni 4 BAR MAP sensor on the way along with a "fast responding" IAT sensor that I will wire into the MAF harness. I will make it plug and play so that if I want to run the stock IAT sensor I can just switch the plugs. I have an aluminum bung that will be tig welded onto the FMIC charge pipe to place the new IAT just before the throttle body.

Is anyone else now running the speed density patch for Open Source (or Cobb for that matter)? I know some STI folks have been. I have been reading up on the subject a fair amount and will be testing out the new sensors with the MAF setup as I read more about the theory and application of speed density.

 

I'm hoping to eventually learn how to apply my own patches to my ROM. For example, I would really like to integrate an accurate oil pressure sensor to tie directly into a spare input on the ECU (my TGV's are gone for example) to drop the IAM and flash the CEL if the pressure drops too low. Maybe that's getting too far into standalone territory though.

[Windy Road]

I was pondering running SD since I'm FMIC'd. Any info on NSFW's patch?

 

Also in for answers lol

[NSFW]

For example, I would really like to integrate an accurate oil pressure sensor to tie directly into a spare input on the ECU (my TGV's are gone for example) to drop the IAT and flash the CEL if the pressure drops too low. Maybe that's getting too far into standalone territory though.

 

Dropping IAM = easy.

Flashing CEL = hard for me, but Merp figured it out and I think he'll explain it at some point.

 

But if oil pressure drops, I think fuel cut would be the best response, and that would be pretty easy.

 

I was pondering running SD since I'm FMIC'd. Any info on NSFW's patch?

 

This is where the patch is, and there's some info about it:

http://www.romraider.com/forum/viewtopic.php?f=37&t=7818

 

Basically, I revised the ECU code so that in addition to calculating the MAF value from the MAF sensor signal and MAF scaling table, it also calculates the MAF value based on manifold pressure, intake temperature, RPM, and a VE table.

 

There's a switch in the ROM that determines which MAF value actually gets used (SD or regular), so you can get the VE table tuned by logging the SD MAF and regular MAF values, and then switch to SD when you're satisfied with the table.

 

I got the idea from Freon, who did essentially the same thing for his 04 STI. His thread has some more information about how it works and how to tune it:

 

http://www.romraider.com/forum/viewtopic.php?f=37&t=2947

 

My car has been running this patch for months, BUT it has been running in "MAF mode" the whole time. Shortly after I finished the patch, I had to deal with some difficult events (totally unrelated to cars) and I haven't gotten back to tuning yet. Somewhere along the way, my logger started cutting out a lot, which makes tuning a real pain.

[bnguyenbb6]

NSFW, try the Tactrix obd2 extension. Mine started cutting out and I had a feeling it was the connectors. Bought an extension and everything works fine now. If the connectors wear down, its just another $15 extension.

[NSFW]

Thanks for the suggestion. As luck would have it, I actually have one already, I just haven't tried it in my car. I'll give it a shot.

[Th3Franz]

I've thought about upgrading to a Tactrix 2.0 to see if my logger interruptions go away. I would like the memory card logging capability too.

Installing my new MAP sensor and IAT sensor this weekend.

Thanks to td-d I have the memory addresses to disable learning D and already disabled AF correction #3 and my car runs at stoich much more frequently in closed loop now (rear O2 sensor completely removed, catless car).

 

Thanks for your help so far with the patches, NSFW. I know you have had a lot of other stuff going on, but I'm looking forward to what more you come up with on the tuning front.

[Th3Franz]

IAT sensor installed. I found a calibration for the GM/Delco sensor. I believe the resistor is different on the LGT, so I used a spreadsheet by ryanr from the romraider forums that uses the stock table + the GM cal to get the new cal for the car. It seems really close. I'm reading 1-2 degrees warmer than ambient when cruising around on the highway. FMIC + heat wrap and ceramic coating ftw.

 

Omnipower 4 BAR sensor also installed. I might need to tweak the scaling for it, but I used one that was posted on nasioc. The Toyota Supra one is in fact plug and play for the Legacy which is awesome.

 

After I verify the IAT sensor is quick enough to respond, I'll finish dialing my MAF and give speed density a try.

[seabass07]

Thanks for the suggestion. As luck would have it, I actually have one already, I just haven't tried it in my car. I'll give it a shot.

 

Anything?

[Th3Franz]

I am planning to patch my ROM this weekend and do some VE logging while on MAF to get a good starting point for my VE table once I switch to SD.

[McDowell Performance Tunin]

I've thought about upgrading to a Tactrix 2.0 to see if my logger interruptions go away. I would like the memory card logging capability too.

Installing my new MAP sensor and IAT sensor this weekend.

Thanks to td-d I have the memory addresses to disable learning D and already disabled AF correction #3 and my car runs at stoich much more frequently in closed loop now (rear O2 sensor completely removed, catless car).

 

Thanks for your help so far with the patches, NSFW. I know you have had a lot of other stuff going on, but I'm looking forward to what more you come up with on the tuning front.

 

Going from a 1.3 Vag-Com cable to the 2.0 Tactrix cable makes a big difference in the rate at which it reads data. Not only did it fix the interruptions, but it gives better readings because of the fast data transfer rate, yielding more accurate data.