I'm brand new to tuning and I'm getting ready to tune my Procharged Ws6. Should make 600-650 with 14psi or so.
I was originally going to do an speed density tune but now I'm seeing a lot of talk about using an LS7 mass air flow sensor.

Can someone give me the pros and cons to both?
Especially someone new to tuning.

thanks

 

Maf table is quicker to tune than a multibar VE table and accounts for weather better than most SD tunes that most tuners do. Downside is when you hit a limit in the PCM for either airflow or maf frequency you have to scale the tune and go with a larger maf housing.

Multibar SD tune requires a custom operating system for boost. SD can be a benefit on NA cars by removing an intake restriction. SD also cleans up pipe routing and a sensor that can fail.

Alot of people for a long time said you absolutely HAD to go SD if you went boosted but there's been a comeback in using large MAFs like the LS7 for big NA and boost setups.

 

Now that larger MAFs are available that don't max out too early, I would still dial in a proper multi bar tune, but also re-enable and tune the MAF. That would give full factory style functionality and redundancy. I have previously done this on lower power boost setups. Having a MAF with a maxed out 1 bar MAP can lead to poor throttle transient response. You can tune around it, but I prefer the crisp throttle response of a spot-on sd tune. I also understand the benefits of keeping a MAF, although if a motor was going to make enough to max it, I always tossed them out.

 

Sometimes it is not the maf that maxes out it is the Ecu. Especially on a boosted car and the gen 3 controllers. 512 g/sec is it.

 

Yep, then it's time to scale.

 

I tried tuning a card style MAF with a 4 inch tube on a boosted LQ4 with a Gen 3 ECU. Still maxed the ECU. Was going to scale it BUT I decided to tune it in SD. Cold starts and drivability are fine.

 

What % did you scale the tune?

 

I didnt scale it. I hate the loss of resolution when you scale. Now I recently scaled an E67 because the injectors were larger than the ECM could handle. But if I can avoid it, I will. The P01 and P59 pretty much should be SD if boosted.

 

The loss of resolution really is negligible when it comes to the impact on drivability if done right. But everybody has a different way of getting it done.

 

I scaled one by 50%. It drove ok but I personally didnt like how it LOOKED in the scanner. It ran fine fine tho. Maybe im just a little off. LOL

 

Its possible. I usually go 50% and the ipw and load is all the same. The only thing different is airflow and g/sec. Doing 50% scale means you just need to double the value for the real value.

 

With my mild supercharger setup, would I be Okay using a 85mm maf?

 

If you're tuning it yourself you may as well try it. Pretty easy to make a couple pulls and dial in the mag curve. If you max it then decide if you want to go SD or move to a bigger maf.