FN320A & FN337

[DOHCTOR_32V]

Hello, will the perload entries in FN320A & FN337 from the T4M2 tune force closed loop at WOT, high load / RPM in an NA application, or is open loop being forced by FN513, or in some other way?

[decipha]

fn320a yes

you dont have tunerpro setup properly as per the getting started write up

[DOHCTOR_32V]

Thank You for your advice and patience Decipha. I now have TunerPro set up properly, and now my rows are easier to deal with!

So, is the T4M2 tune intended to stay in closed loop at WOT, high load & RPM, and will it foul up the T4M2 calibration if the FN320A and FN337 entries are brought down to something like 75 perload without modifying other related tables or parameters?

I'm trying to better understand your approach and intentions beyond my thought that the tune was set up to use either NA, or with boost. Also that it may be more beneficial to stay in closed loop at WOT with T4M2 and NA.

I have modified the "MINIMUM changes REQUIRED" as per your T4M2 write up.

[decipha]

No, why would you want to stay closed loop at WOT ?

75 perload is far too low for power enrichment not to mention the fuel table commands stoich at .75 perload anyways so it would be in open loop with no enrichment defeating the purpose. 88-95% perload for enrichment is typical if you want to lower fn320a otherwise the stock value is fine at 3.5 lbs of boost.

Keep in mind you also get open loop from throttle position when you exceed half throttle which should put you in the 90% perload range so long as you have FN035 the peak load at 0 vac and 0 boost function dialed in properly.

[DOHCTOR_32V]

I was asking about the FN320A and FN337 settings in T4M2 because my engine is NA and I didn't think I needed to be in closed loop at WOT, but I was under the impression the original settings in T4M2 would keep it in closed loop, and If so, you may have had a good reason to set it up that way.

I was trying to get clearer understanding of how the T4M2 tune as provided, would switch to open loop with the perload settings in FN320A and FN337 being above what my engine would reach. I believe FN513 and TP WOT breakpoint OL Threshold should be involved. Would you mind giving more details on this?

I have pretty accurate values in FN035 until I can log them again.

[decipha]

Yeah easy enough, if any open loop threshold gets exceeded she goes in to open loop.

[DOHCTOR_32V]

Thanks Decipha. I was hung up on the idea that one threshold could possibly keep it in CL. So basically for NA, I will enter .88 perload into FN320A only and it will override FN337, or I could enter .88 perload into both FN320A and FN337 and there will be no consequence as long as FN035 is set up correctly, as well as FN513 and THBP2 (TP WOT breakpoint OL Threshold) being set up correctly or left as provided in the T4M2 calibration. Correct?

[decipha]

You can leave all as-is as its already optimal for your setup.

[DOHCTOR_32V]

One last question on this please. Am I to take the understanding that FN320a perload being set to all 1.20 and FN337 at 2.00 is optimal or non consequential for NA, due to what you previously said about FN035, TP WOT Breakpoint and FN513 taking precedence, so FN320a and FN337 perload entries do not matter?

[decipha]

correct

FN320a will put you in to open loop at 3.5lbs of boost which you'll never reach since your n/a. You can lower this to .90 if you desire.
FN337 is disabled so it doesn't do anything regardless.
FN513 the wot ol threshold is set to 70% throttle position (550 tprel) to go in to ol.
THBP2 the ol threshold is set to 80% throttle position (625 tprel) to go in to ol.