Bowtie70SS

iTrader: (10)

I have been looking at MAF options and it seems to me that the LS7 MAP sensor would make the most sense. Also I have a brand new one already. I have been searching for a informative thread with install tips and experiences. I have access to a machine shop (and a guy who can use it lol) so making a housing wont be a problem. Other than a adapter to split off the IAT and MAF and making sure to orient it in the proper direction what else is there? I mean other than proper tuning.

vmapper

iTrader: (8)

In the past I used the Hitatchi slot Sensor, the IAT is built into it.
The IAT sensor curve required adjusting.

This is the same sensor used in the PowrMAF 103mm... and is an LS7 sensor i do believe.
id have to check my notes to make sure.

Bowtie70SS

iTrader: (10)

I am a novice tuner but I need to know the exact diameter of the MAF housing I build to get in the ball park when I am calibrating, correct?

FuzzyLog1c

iTrader: (4)

Why not buy the PowrMAF and call it a day? They've got tables premade for you. Vmapper, do you have any experience with it? Don Kinder @ Slowhawk mocks that part because it's a LS3 MAF, but he won't elaborate.

Bowtie70SS

iTrader: (10)

That is a good point. I get in the habit of having to make stuff for the old cars I work on and some times can't see the forest for the trees. I thought, however, that the MAF for the LS7 is the same one? I have a GMPP LS7 retro kit (wiring and sensors) and was going to snag it from there. I guess for $199 though you cant argue. I hate that I am going to have to figure out something for the Volant intake that I have. I love the way is looks and that it is a true cold air intake and not open to engine heat. Oh well, next hurdle I will figure it out.

vmapper

iTrader: (8)

I checked, the Hitachi GM pn 15865791 same as LS7.
You can either buy the 103mm MAF
or buy the slot sensor, a bung, and install in your own intake pipe (or charge pipe).

You dont need to know the diameter at all, it doest work that way.

(you can buy the PowrMAF, use the table provided) but in the end, Im going to doubt you are stock, you will have mods, so a re-calibration of the MAF table (curve) is necessary anyways.
With that being said:
You can choose the diameter, and then recalibrate the MAF.

Due to MAF Hz limits, going with a larger diameter would slow air velocity keeping you under a tunable curve, giving you a 32% more headroom (the next limit would be the 511g/sec ECM limit).

e.g. 3" diameter pipe MAF, maxes out the Hz, you just slow air velocity by increasing the pipe size to 4", re-calibrate the MAF curve... problem solved..


Ive used the PowrMaf 103mm in the past on N/A setups. I will point out, being FI, it was useless. the plastic housing would buckle when tightening down with good clamps. (bought a slot maf bung and migrated to a pipe)

The IAT re-calibration is recommended, just follow what i posted. (There are some threads on HPTuners buried somewhere im sure.)

I also used a mesh screen to straighten flow.
this MAF is somewhat tedious to tune at idle and low rpm, just because the airflow is so slow when using +4" pipe.
again, i could go into this with scan logs, but there is no need. the MAF reading is smoothed substantially.

The aluminum 5:1 honeycomb 103mm (you can request this size) or purchase the 100mm comes from www.saxonpc.com/100mm-cells-for-100.html
Is it necessary? no, but it its noticeable and easier to tune, rather than having a jumpy measurement.
Note, this is if you decide to run MAF only, which I have done in the past. (you can run the standard preferred blend method) MAF/SD up to xxxx rpm, then MAF only. This reduces these anomalies.


I have since went to what I always prefer, S.D. (speed density), so now this fancy Slot sensor is only used for IAT.

vmapper

iTrader: (8)

I do recall having to rewire.... using the PowrMaf...

Bowtie70SS

iTrader: (10)

I didn't really consider a speed density tune. Are there any real disadvantages? I am going to be NA so I wouldnt even need a different map sensor would I? And I will have someone helping on the tune.

vmapper

iTrader: (8)

I prefer S.D.


SD is math calculations while MAF is measuring the air density.
Though one would think the MAF is more accurate, the drawbacks are the tip in and throttle off, and air turbulence (but the honeycomb does help)
When you mash on it, the air already past the MAF (already measured) is ingested (hesitation / Lean) and let off, rich) - like a wet sponge...
MAF is one nice curve to tune... pretty easy.
While SD calculates and fuels instantly. Throttle response Ive always found is crisper.

SD does require accurate IAT however, heat soak will drift your IPW. No good.


If your n/a, you can use the MAP sensor you already have.

Just a note, another advantage to SD for FI is the ability to actually see the boost (MAF does not see boost) and you can leverage off the BE (boost enrichment) tables.

Bowtie70SS

iTrader: (10)

I didn't really consider a speed density tune. Are there any real disadvantages? I am going to be NA so I wouldnt even need a different map sensor would I? And I will have someone helping on the tune.