Volumetric Efficency

[figgie]

Ok folks,

I know this will probably be over the majority of everyone head here so bare with me.

This might be easier done by the folks that have a MAFT-PRO.

Anyway I need a graph of the measured MAF/AFM value v.s the RPM through wot would be fine. In short I need to compare this to theoretical to come up with an estimated VE for each RPM point.

7m NA or Turbo. At this point it does not matter.

 

[CPT Furious]

Let me check some of my logs...

 

[isnms]

Doward started a really good write up on MKIIITECH, but I don't think it was completed.
He does mention VE in it
http://www.mkiiitech.com/forum/showthread.php?t=1001
hth

 

[Kckazdude]

Doward started a really good write up on MKIIITECH, but I don't think it was completed.
He does mention VE in it
http://www.mkiiitech.com/forum/showthread.php?t=1001
hth

YES!!!
I have been searching for that thread again. Thank you for posting it for me.

 

[CPT Furious]

I know this probably isn't the detail you need, but something along these lines?

 

[figgie]

CPT_Furious, that will work, anyway to dump that to a 3d txt grid (csv file)?

 

[CPT Furious]

I'm checking with some smarter guys than me, hold on...

 

[CPT Furious]

Here you go! I'm running speed density, so the grams/sec is pretty far on the right. This was from a session while drag racing, so you'll see the idle, burnout, idle again, then the run, followed by coast down. LMK if this works for ya!

 

[figgie]

Here you go! I'm running speed density, so the grams/sec is pretty far on the right. This was from a session while drag racing, so you'll see the idle, burnout, idle again, then the run, followed by coast down. LMK if this works for ya!

CPT

Thanks for that!

The SD_Mass_Airflow_Grams/S. How does it arrive at this value? What does it use to calculate it?

This will actually help alot to plot the ENTIRE VE curve for your motor which I can then I will need more than your motor to average them out.


any head work?
Cams?
Exhaust?
Intake?

 

[grimreaper]

CPT

Thanks for that!

The SD_Mass_Airflow_Grams/S. How does it arrive at this value? What does it use to calculate it?

This will actually help alot to plot the ENTIRE VE curve for your motor which I can then I will need more than your motor to average them out.


any head work?
Cams?
Exhaust?
Intake?

ill have mine setup in a week or two if you want another 7m log to compare to. LMK?

 

[CPT Furious]

Figgie,

I'm not sure, but turbobob is pretty much the man for the Pro. Dr Jonez might know, too, although I haven't seen him much lately. Gimme a little bit and I'll ask Bob.

I don't have any headwork and they are the stock 7M cams. The exhaust is the stock manifold as well with the BIC SP61GT specific DDP bolted up to the Tanabe Hyper Medallion exhaust. Intake is just a conical filter to the SP61GT which spews the air forth to the 24x12x3.5 intercooler. Piping is pretty much a constant 2.5". Stock manifold for now as well. Injectors are old HKS 550's. Boost controlled by the Pro as well as the fueling (I didn't have the boost control running on the run, hence why it stops at around 12~ish.

 

[turbobob]

The Pro calculates Airflow just like most true speed density controllers and ECU's.

Take (engine displacement/2) * RPM * VE * air density in the intake manifold

The Pro has 2 default VE tables built in, but can be easily user edited...

Analyzing a logfile and comparing MAF airflow to SD airflow is a good way to optimize the Pro's VE table.

Bob