[WolfPlayer]

I installed the APS 70mm Intake and tuned it. I have attached the XLS of the MAF curve to this post. Make sure to look at the 'Data Table' tab in the XLS and read the 2 notes.

t

[RainMaker]

Im not sure what "Service Unavailable" means, but I got it... could be the fat angry proxy server that I have to visit with y'all through....

Thanks for the calibration/X-fer function though...

EDIT: I just got the lovely graph... thanks...

-Chris

[R4ND0M_AX3]

I like.



woa. I just looked at the difference as a percentage of change and plotted it. It is what it is. damn I wish this thing had a CARB number on it.

[WolfPlayer]

Yea ...

Down low the percentages can be a huge difference. I think this is because it is so darn free flowing that it is so easy to ingest air at those low MAF volts. As air starts pushing through then it begins to represent what you think it would (around 16% or so). I'm still going to tweak this a bit. I only have 2 days creating this calibration (but have revised it a few times based off of a few different 30 minute logs).

Again, please keep in mind that this is for my car. YMMV.

t

[Rootus]

Am I reading it right -- the APS intake is making the MAF read incorrectly 16%?

Dave

[cnstman]

good work, can you explain your method for tuning the intake calibration table? dyno? road tuning?

thanks.

also is this with the stock turbo inlet pipe?

[WolfPlayer]

Originally Posted by Rootus

Am I reading it right -- the APS intake is making the MAF read incorrectly 16%?

Dave

ROFL. Do a search on what a Big MAF is

t

[WolfPlayer]

Originally Posted by cnstman

good work, can you explain your method for tuningy the intake calibration table? dyno? road tuning?

thanks.

also is this with the stock turbo inlet pipe?

Christian from Cobb, Daemon, and Nhluhr all have very nice writeups on tuning the calibration. Definitely check those posts out if you haven't already. I'm lazy, so here is what I did.

1) Calculated the overall increase in area between the 65mm stock airbox and the big MAF. (PIr^2, etc.). 16% in this case (for those reading this post who have a stock sized 65mm MAF then ignore this step and the next one).
2) Multiply whole MAF table by 16%.
3) Start car and watch the air fuel corrections in ST.
4) Adjust the idle MAF cells to give near 0 correction.
5) Stab the gas a little, watch the corrections and AFR.
6) Go for a normal drive (no WOT, no heavy acceleration). Watch the AFR to ensure no extremely lean areas. Check low boost areas (5psi or so) to ensure no leanness. If so - stop. Adjust those areas and increase the g/s values for those MAF volts. Smooth the adjacent cells to ensure there is absolutely no spiking or harsh peaks.
7) Log data and drive for about 20 minutes or so trying to hit all types of driving but not exceeding 5psi (verified to NOT be lean through #6). While driving try to HOLD the throttle still at various loads. This will give the trims a moment to settle so that you get good readings for what needs to be corrected.
8) Go home, pull up the data in excel. Create a new column and add the short and long trims together.
9) Start a new excel spreadsheet and paste the current MAF table in there. Start making adjustments to particular MAF cells based on #8 using the new total column. Choose the areas where the accelerator pedal was steady and the car wasn't in decel enleanment. Example: If a 10% correction is needed for a particular MAF voltage then take the g/s for that MAF voltage and multiply it by 0.10 and then add it back to itself. Easy as pie. Do as many of these as possible. Ignore anything that is in open loop for now (0.39/0.39 short/long trims).
10) Graph the resultant values in 9. Interpolate between the points to create a nice smooth flow to the graph. This is the black magic - lol.
11) Repeat starting at #6.
12) Bring up the live data view and watch the AFRs. Do extremely short burts of more and more throttle verifying that you are getting plenty of fuel and the car is running rich. When you are sure, do very short bursts of WOT. Go higher and higher in the RPMs. Verify you are rich. Still NOT logging at this point.
13) Log a normal drive with some WOT in 3rd gear from 2000rpms to redline.
14) Check the AFRs for WOT and make sure they agree with what you had previously. If not, then modify the higher MAF voltage gram/sec values (the ones in the logs) such that you obtain the previous AFRs.
15) Do step 10 again but this time with the higher MAF voltages.
16) Repeat 6-15 again.

My way is labor intensive. I'm totally capable of some cool excel stuff but I really wanted to get down and dirty on this one. I wanted to page through the excel logs and view everything as I was putting stuff together.

t

[Rootus]

Originally Posted by WolfPlayer

ROFL. Do a search on what a Big MAF is

So this replaces the MAF with a larger housing. That was what I was trying to clarify . We've been doing it with Mustangs for years, there's nothing wrong with the idea. I was confused and thought it was just a CAI, and it was screwing up the flow into the MAF. Carry on...

Dave

[cnstman]

Originally Posted by Rootus

So this replaces the MAF with a larger housing. That was what I was trying to clarify . We've been doing it with Mustangs for years, there's nothing wrong with the idea. I was confused and thought it was just a CAI, and it was screwing up the flow into the MAF. Carry on...

Dave

APS has 2 CAI, one 65 mm (stock size) one 70 mm (5mm over stock) so yes it has a larger MAF housing.

[Rootus]

Any idea what kind of power level the 70mm MAF is good up to before it pegs?

[R4ND0M_AX3]

Originally Posted by Rootus

Any idea what kind of power level the 70mm MAF is good up to before it pegs?

Well, it's good for about 16% more grams per second of airflow. How you use that air will determine how much power you ultimately make.

[Rootus]

Where does the stock one typically peg?

[jays05]

I pegged the stock MAF with my GT35R around 20psi. (probably around 400whp).

At 25psi and maybe 450ish whp it looks like I would be very close to pegging the MAF in the APS 70mm CAI.

The APS 70mm CAI looks like a nice half-way point between the stock MAF and the Perrin BigMAF.

[R4ND0M_AX3]

Originally Posted by Rootus

Where does the stock one typically peg?

about 4.8volts or a little over 320 g/s.