Open Loop Maf Tuning

[mtcrusan]

Are you using the "multiply by % half" function whan adjusting your MAF table?

Yes I am. I get a spike during the transient stage. I want to make it close, but now it seems to overshoot either way most times. I appreciate the help.

[LNorton]

Russ,

I would like to get the MAF dialed in on the race car. How do I go about doing this since I cannot take the car out and log any street miles. I am limited to my driveway and the little bit of driving time around the pits.

I may be able to get into our local track a few hours early and have free reign to cruise the return road for a few hours, but I also dont see this as being enough time.

So. How can I dial the MAF in this situation?

[98gtp]

Russ,

I would like to get the MAF dialed in on the race car. How do I go about doing this since I cannot take the car out and log any street miles. I am limited to my driveway and the little bit of driving time around the pits.

I may be able to get into our local track a few hours early and have free reign to cruise the return road for a few hours, but I also dont see this as being enough time.

So. How can I dial the MAF in this situation?

dyno.

[LNorton]

Dyno is out of the equation on this one. Dont have the time to get to a dyno during the week with the right resources, and we race pretty much every weekend.

[MMGT1]

If you can get your runs in and still have a good day, use a couple of runs without "hammering" it. (Use the 1/4 to street tune it) What you are saying about getting a bit of track time I think you can get it pretty dam close!

[louvered97gtp]

Get to the track early a few times. I think you can incrementally tune it if you log a count of at least 100 hits on each cell in your MAF. Set your histogram to display cell count hits. Just slowly oscillate your rpm watching to make sure you hit all the cells, and that should be descent to get you started on a tune, reflash and do over. Slow process with only 100 hits per scan, but at moment your limited as you said. I'm limited in traffic at times as well and have used this method.

[mtcrusan]

I put some 100 octane in my car and my knock went away. I will order a larger pulley and re gap the plugs to 0.040 and see. I will post logs soon.

[Lastyear4gt]

OK, so as far as I can see once this process has been completed, the LTFT's and STFT's should be pretty close to zero?

I always thought that you were supposed to get your fuel trims in order before you can complete a VE tune?

I'll have to disable the open loop through the VCM editor because I have the WB wired for NB as well.

Oh, and I am having a hard time finding the Maf AFR histogram too.

[eclipse5302]

Russ - first of all great guide.

Second of all I was wondering if you could quickly walk us through a drive cycle? What things are you doing and what are you trying to achieve? I'm wondering how you hit all the cells in such a short time...

Lastly, I'm having trouble getting good results. I've read and followed the directions as close as possible, but here's what I'm getting. On the first run, I'll get like average -47 across the board, and when I do a paste special / Multiply % and rescan, the numbers are now 47-50 across the board. It seems like I end up over-correcting back and forth with every scan.

I've set the CL enable temp set to 230 degrees since my WB is in the stock location and doing simulation of the NB for the PCM (and I don't want to cut wires).

Am I missing something?

[eclipse5302]

Edit on last post - my WB was WAYYYY out of calibration. After calibrating it, I was able to perform the procedure and it works like a charm! Silly LC1

[BEEDEEBEE]

So just to clarify. We put the wideband in place of the stock 02 and run the wideband into the HPtuner?

If I've already got a bung welded in I should just unplug the sensor and use that right?

[Russ K]

So just to clarify. We put the wideband in place of the stock 02 and run the wideband into the HPtuner?

If I've already got a bung welded in I should just unplug the sensor and use that right?

Yes, you can unplug the stock O2 sensor, and install the wideband into the weld bung.

I always install the wideband in place of the stock O2 sensor when I tune a vehicle, no need to weld in a bung.

Russ Kemp

[MMGT1]

Thanks to Russ, I still have the bung that my WB came with. One less hole to rust out as far as I'm concerned! Good tip bud

Paul

[00GTP]

I put some 100 octane in my car and my knock went away. I will order a larger pulley and re gap the plugs to 0.040 and see. I will post logs soon.

Mitchell, what size pulley are you running now with the kr? The mods you have should support the 3.4

[OldskoolGTP]

My scanner configuration doesn't have the MAF AFR histogram or the MAF % error histogram Russ talks about. How do I create those (i.e. what sensors, table parameters)?

[CSC04]

My scanner configuration doesn't have the MAF AFR histogram or the MAF % error histogram Russ talks about. How do I create those (i.e. what sensors, table parameters)?

Here's a link that helped me a ton.

http://gtpworldforum.yuku.com/topic/...s.html?page=-1

[GTPNoga]

This is too funny… I made that post around the time the guys on my local hangout were starting to move from the DHP Tuner to the HPT.. They wanted to see what the interface looks like. I have nothing but good things to say about the HPT MPVI. I need to update that post some it some. There are way better guides out there…
I also did a write up on installing the NGK AFX via the EGR....

[Russ K]

My scanner configuration doesn't have the MAF AFR histogram or the MAF % error histogram Russ talks about. How do I create those (i.e. what sensors, table parameters)?

Just insert your brand of wideband in place of my FJO in the table display.

Russ Kemp

[OldskoolGTP]

Thanks! This config is working, but my commanded AFR is jumping around. When I have the engine off with key on, it says it's commanding 14.00, but I have the Base AFR for PE set to 14.7. Then when I'm driving around it jumps around between 14.2 and 13.8. Could the AE modifiers be messing with my commanded AFR?

[GTPNoga]

Mine has been doing that too... 13.60 sometimes. Don't know where its coming from.