MAF Flat at 48 lb/min on scaled tune

[HoP]

The vehicle has a AA supercharger kit with their redrilled LS2 injectors which are supposed to be 60 lbs at 43.5 psi. It runs 5 psi of boost. I've scaled the tune at .50%. The problem I have is the MAF is flatlined at 48.90 lb/min at @5800 rpm's. I was under the impression that by scaling the maf and the IFR by.50 would allow for more head room on the maf but this one is not having it at all. Any help on this would be greatly appreciated.

[5_Liter_Eater]

What diameter is the MAF pipe? Scaling will only address the airflow but you're maxing out the frequency at 12,200 hz. You need a bigger diameter MAF, 100mm/4", to gain more airflow for the frequency range.

[HoP]

What diameter is the MAF pipe? Scaling will only address the airflow but you're maxing out the frequency at 12,200 hz. You need a bigger diameter MAF, 100mm/4", to gain more airflow for the frequency range.

AA's kit uses the factory LS2 MAF. I'd like to run a different MAF but this is one of their CARB legal kits.

[eficalibrator]

AA's kit uses the factory LS2 MAF. I'd like to run a different MAF but this is one of their CARB legal kits.

Once you change the PCM's calibration file ("the tune"), it's no longer the same specification that was CARB certified. I would suggest getting a proper (larger capacity) MAF sensor to avoid pegging the frequency limit and work from there. The LPE unit should fit pretty easily, or you can switch over to an LS3/7 slot style element in the same tube size as your OE MAF. Just make sure that you correct the IAT transfer function if you're changing that as well as it is intergrated into the MAF on some applications.

[DSteck]

Use SD and end your worries.

[Ben Charles]

Yep looks like your slamming into the HZ limit.

On a side note, how much boost did you hit? My Boost PID shows .2???
I am using [PID.11.PSI]-14.7 and it shows correcty with negative pressures outside of boost.

[eficalibrator]

On a side note, how much boost did you hit? My Boost PID shows .2???
I am using [PID.11.PSI]-14.7 and it shows correcty with negative pressures outside of boost.

This works a lot better if you have a 2bar or greater MAP sensor. Most supercharger kits do not include an upgrade to the MAP sensor.

[5_Liter_Eater]

So you have options. In order of most ideal to least:

Get a 2, 2.5 or 5 bar MAP and run the 2 bar speed density OS.

Get the LS3 charge pipe from Andy, which should be 4" diameter and an LS3/7 MAF. Recalibrate the MAF table. The 4" pipe will give you enough range to stay under the Hz limit.

Since it's a centri it's pretty much going to peg the MAF at the same RPM every time. So rape the PE after the MAF maxes out which for you is 5500. Start commanding more and more fuel via the PE after 5500 RPM to account for the extra airflow that the MAF cannot meter. This is the least desirable because you're not metering the air past 5500. So tune it now in the summer and when winter comes, the car will be making more boost and cannot account for it.

[HoP]

Thanks for the input. I decided to use the LPE maf. Sucks that its an additional cost for the customer. You'd think the manufacturer would know about this condition already.

[5_Liter_Eater]

Pretty sure if you got a canned tune from Andy for an LS2 kit i would have the PE altered past 5500.

[HoP]

Pretty sure if you got a canned tune from Andy for an LS2 kit i would have the PE altered past 5500.

I bet your right

[5_Liter_Eater]

I bet your right

I'm not dogging it. The canned tune from ECS or Procharger or Whipple or anyone would have to be the same way on an LS2 car.

[IDRIVEAG8GT]

Yep looks like your slamming into the HZ limit.

On a side note, how much boost did you hit? My Boost PID shows .2???
I am using [PID.11.PSI]-14.7 and it shows correcty with negative pressures outside of boost.

ROFL ^ Boost fail