Quick questions fellas; just want to verify something.

Is it a factual statement that a load of P20 on the PFC is equivalent to about 14.2 kg/cm2 of boost? If true, would that also mean that at about P10 the engine is transitioning between vacuum and boost. If none of the above is true then please elaborate on what the level of boost is at each load (e.g., p10-p20). Please note the units you are referring to.

Many thanks

Ramon

 

P rows are absolute pressure rows for determining
what row to use at what boost.

P20 = 24000 ABS.

Real world/relative/your boost gauge pressure is:

((24000 / 10000) * 14.22) - 14.7 = 19.428 PSI.

But the PFC has a conversion problem as it calculates this value from the map sensor voltage. Check past posts about this.

Also from my DATALOGIT testing, that pressure if it was accurate, would be the lowest point/begining for that row.

My logs all show the PFC using the row lower than the row matching the boost being run at that time. There is also a one row and column diff between what the log has and what the mapwatch has.

I had a 14psi run with overboost in the low revs to out 15.6 PSI based on AUTOMETER and BLITZ controller, but the PFC listed it as 96 which equates to 13.7 psi. It used row 17 from about 13 up to 15.6 psi. If you use that 2000 diff between the higher rows, resolution is lost compared to the lower rows which change by 1000. ALmost 3 psi for 2000 diff.

 

Thanks Chuck. You've always been a ton of help. Maybe I missed it, but I couldn't find in the manual where it is stated that ABS is 24000. In any case, your formula was real helpful. This is what I determined:

P-Load ABS PSI
1 1200 -13.0
2 2400 -11.3
3 3600 -9.6
4 4800 -7.9
5 6000 -6.2
6 7200 -4.5
7 8400 -2.8
8 9600 -1.0
9 10800 0.7
10 12000 2.4
11 13200 4.1
12 14400 5.8
13 15600 7.5
14 16800 9.2
15 18000 10.9
16 19200 12.6
17 20400 14.3
18 21600 16.0
19 22800 17.7
20 24000 19.4


I originally asked this question so I knew what timing I had in my maps at certain boost levels (so I could compare maps with some guys that have Haltechs).

thanks again.

 

Just be aware that the stock map sensor tops out about 22000 at a listed boost value of 115 which is equivalent to about 1.15 atm. Don't quote me on the units, the PFC is a bit querky on reported boost values, P row, and PIM ...

 

so regarding the "boost settings" screen of the PFC

what does pri/sec mean? primary/secondary turbo? where is the prespool adjustment?

also, what about the duty cycles, is that percent open or percent closed, and if i set mine to let's say 10psi, (.70), does it learn how to keep it at .70? does it change/update the duty cycles?

someone explain this to me in great detail