Speed density 2.5 MAP OS for LS2

The 2.5 BAR OS states that it is "Speed Density Mode *ONLY*". Does this mean the MAF is totally ignored by installing this OS with no other changes? The "Application Procedure (LS2 E40 ECM)" does not methion anything about disabling the MAF when installing the 2.5 BAR OS.

I ask because many threads mention changing MAF fail high/low to zero to disable the MAF...mostly for tuning the VE table without the MAF altering the fuel calc. So I'm confused as to whether or not the MAF is utilized if I don't set the fail parameters to zero.

I realize that if I want to remove the MAF from the car, I need to modify the MIL light settings for the MAF. But for the time being, the MAF is still on the car.

This is an E40 ECU in a 2006 GTO.

Thanks,
-Mike

it should still work with the MAF, the reason it says SD only is because we didn't design it for MAF and hence never tested it that way. However, people have had success.

Thank you Chris!

So if I wanted to still run MAF for fueling, yet have all the cool things like boost PE, fan settings, etc.. All I would have to do is not fail the MAF?

correct, leave the MAF fitted and enabled. The VE is still used but not exclusively, the dynamic airflow calculations blend the MAF & VE. It is only exclusively used when the MAF fails.

Suppose I had dyn airflow disabled - and in the boost regions of the VE table I had 0s or just incorrect data.. Would transient fueling (or anything else that might reference VE) get screwed and cause problems? I'd like to initially use the extra features and use the 2bar map setup as a boost gauge.

So, Chris, what are the steps to tuning the VE table by disabling the MAF?
I would like to do this, but I'm not sure how to do it.

I have a '06 GTO with the E40 as well.

Thanks in advance!

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Originally Posted by Blades

Suppose I had dyn airflow disabled - and in the boost regions of the VE table I had 0s or just incorrect data.. Would transient fueling (or anything else that might reference VE) get screwed and cause problems? I'd like to initially use the extra features and use the 2bar map setup as a boost gauge.

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personally i would make an effort to get reasonable numbers in the VE table even if you have dyn air disabled - just in case.

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Originally Posted by Gregory

So, Chris, what are the steps to tuning the VE table by disabling the MAF?
I would like to do this, but I'm not sure how to do it.

I have a '06 GTO with the E40 as well.

Thanks in advance!

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check out the speed density tutorials. basically, you need a wideband and need to load in the AFR % Error histograms in the scanner. Then you use the AFR % error to correct the VE.

The idea is to get the measured wideband AFR to match the commanded AFR (from your PE table or Boost Enrich).

Chris...

4 years later...I can confirm MAF works in the SD OS. You can even run MAF only...I've done it. :)

Interestingly enough, I have been contemplating 2+bar with MAF.

I run 2.5 bar as MAF only right now. I've just been too lazy to do the VE because the car drives great as is.

The other benefit of having the MAF is if the boost spikes by accident, the ECM will see the extra air and add fuel accordingly. Unlike OL SD.

Open loop has nothing to do with compensating for boost spikes.

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Originally Posted by DSteck

I run 2.5 bar as MAF only right now. I've just been too lazy to do the VE because the car drives great as is.

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DSteck,

What kind of MAF are you running? I'm still using the stock LS2 MAF on the E40 and it's maxing out at 7.5 PSI. I want to try MAF only like you're doing, but I can't until I get a bigger MAF. I also want to up the boost to 10 or 12 PSI...this will obviously be way too much for this LS2 MAF to read.

I haven't thoroughly researched a replacement yet, but have thought about using a ZR1 MAF. I'm not even sure it will work electrically with an E40. I know it has a higher freq output than the E40 can recognize, I'm hoping it won't exceed 12200 with my combo. I guess that will depend on what kind of housing I choose to use.

Until I get a bigger MAF, I've had to switch back to SD only. I did run SD only for more than 2 years with no problems, but I'm ready to try something new. And like you, I'm feeling kind of lazy about tuning the VE tables.

I've scaled my tune by 50% for the FIC1000's, so instead of 512 g/sec, I'm good to 1024 g/sec. (Currently, the stock MAF is calibrated to 271 g/sec at 12200 hz. I'm already surpassing 512 g/sec)

Check out how horribly erratic the MAF gets at ~7.5 PSI (frame 3140-ish)

I use my stock LS7 MAF.

I meant OL SD. Fixed above post. But Im sure you know what I meant. The MAF can see the extra air that the VE table cant compensate for.

Uh, the VE table can register it. It just hits a higher cell on pressure.

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Originally Posted by DSteck

I use my stock LS7 MAF.

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Nice! It appears I can use one of these if I move some wires around and get a housing for it.

Thanks!