Rote8

Will anyone share their Injector size numbers for the Cobb?

I have:
P1 Yellows
P-2 Blue
P3/Aux Blue

I see the stock red is listed as 369 in the AP when on a P-1 position.

I see the stock yellow is listed as 476 in the AP when on a P-2 or Aux position.

I am guessing on 440 for the blue flow rate, but have not seen a 4 port auto map to get an AP number.


From the Cobb math, I see:

The reds flow 290 on P1 = 369 in the ATR software
The yellows flow 390 on P2/3 = 476 in the ATR software
What do the blues flow? (best guess is 440)

*******************from Cobb Help file************************
To calculate a starting value for a different injector size than stock, use the following formula:
New Size Value = (New Injector Size / Original Injector Size) * Original Size Value.

*******************from Cobb Help file************************

For example, let’s say you are replacing your factory RX-8 Bank 1 injector set (290cc) for after market (or other stock sizes) 390cc injectors.

The P-1 formula would look like:
New Size Value = (390cc / 290cc) * 369;
New Size Value = 496

In light of the stock yellows on a P2 or P-3/Aux using 476 for an AP inj size I wonder if I should go with the 476 like the stock P2 size when the yellow is on P-1.


For the blues in P2/3:
New Size Value = (New Injector Size / Original Injector Size) * Original Size Value.

New Size Value = (440 / 390) * 476
New Size Value = 537

So, go with these math derived AP INJ. values and scale the MAF to these injector sizes, or scale these injector sizes to eliminate most of my trims prior to scaling the MAF?


One last time (am I correct now?). the Cobb injector scaling number is not "tunable"; do the math, use that number, scale only the MAF calibration.

ShellDude

iTrader: (12)

you probably already know about this thread: https://www.rx8club.com/series-i-tec...r-info-150432/

one of my favorites

Rote8

I was looking for more of a real world injector size vs Cobb AP number.

So, blue = 480, not 440.


For the blues in P2/3:
New Size Value = (New Injector Size / Original Injector Size) * Original Size Value.

New Size Value = (480 / 380) * 476
New Size Value = 601.2

ShellDude

iTrader: (12)

Ah... I can help....

I still have Race installed from when I used the AP with my 04 4 port auto. Here are the blues in Race:

ShellDude

iTrader: (12)

And check out this post:

https://www.rx8club.com/series-i-eng...2/#post4340811

Rote8

Thank you, you confirmed my P2/3 latency settings.

626 is slightly leaner than my 601 MAF math.

I already started scaling the MAF for a 601 P2/3 injector size.

/Scaling the MAF to the math produced injector size has improved the idle over scaling the injectors.

9krpmrx8

iTrader: (46)

Rote8, the best way to figure it out is to get your injectors flow tested at 58-60psi.

ShellDude

iTrader: (12)

Would someone be willing to post the stock 6MT primary (P1) latency table from Race?

I need to interpolate them into WARI.

TIA!

slash128

TeamRX8

iTrader: (25)

Frickin noobs can't search ....

ShellDude

iTrader: (12)

Slash, what is up with your pressure values?

slash128

That's what it has on the stock tables

TeamRX8

iTrader: (25)

Depends on the unit type selected (US vs rest of world)

ShellDude

iTrader: (12)

ah... got it... simply UOM conversion. Thanks Team!