PowerFC: Some DIY tuning comments please

[paulr33]

where are you getting the 43 from?

i only shifted the first 8x8 or so cells up 8 deg, i dont recall seeing a 43 deg value, ill check tonight

[Robo's]

RPM point 8 = 3200rpm loads 3,4,5, ive got 43 degrees

[justin911]

mines got 48 for those 3

[paulr33]

well ive done a retune again on road runs, in low light load areas. i saw a max ign value of 51 after running monitor ign values for a few minutes and driving around. ive looked at another powerfc tune and realised you can easily up the ign tables by using the airflow correction table, silly me was doing it the slow way of manually editing the ign table directly and doing some runs of ign test mode. anyway ive shifted the first 3 or 4 airflow voltage corrections up around 10% and its now hovering around 10 knock pretty much all the time, which appears great and the car responds really nicely

[benl1981]

Wanting to know off people that are in the know - Is there a point at which you can run too much advance and loose power/fuel economy? 51 deg is a lot of advance

[Robo's]

So you say running the A/F correction .64 volts upto 110%?

[paulr33]

no adjusting the a/f correction depends on your tune and whats been changed. increase it slightly and see if it knocks too much, pretty much the same as ign temp correction and the manually editing the ign cells. increase in small amounts and load simluate and check for knock. dont just go and increase it by like %15 and then hope for the best

[Robo's]

I think i prefer to load them manually through the ignition tables

[paulr33]

Wanting to know off people that are in the know - Is there a point at which you can run too much advance and loose power/fuel economy? 51 deg is a lot of advance

<{POST_SNAPBACK}>

I agree with ben's concerns. Can anyone else enlighten us/confirm/deny?

[Sydneykid]

I agree with ben's concerns. Can anyone else enlighten us/confirm/deny?

<{POST_SNAPBACK}>

Personally I have never seen an RB produce less power with more advance. The limit on how much advance is always pre-ignition not power drop off.

cheers

[benl1981]

So Sk - do you agree with the way Paul R33 is doing his light load ignition tuning. So you could have upwards of 50 deg BTDC at some light load conditions?

I know the knock sensors aren't that accurate but this light load condition tuning would take ages to get right on the dyno..

[Robo's]

Light load would make a difference to throttle response. im not sure about 50 degrees though. I might try a little more down low and see how she goes

[Dale FZ1]

ive looked at another powerfc tune and realised you can easily up the ign tables by using the airflow correction table, silly me was doing it the slow way of manually editing the ign table directly and doing some runs of ign test mode. anyway ive shifted the first 3 or 4 airflow voltage corrections up around 10% and its now hovering around 10 knock pretty much all the time, which appears great and the car responds really nicely

<{POST_SNAPBACK}>

So you adjust the ignition timing by altering AFM correction values upwards?

Does this affect fuelling too?

FWIW, I've found the light load AFM output voltages go up to about 2400mV. Tried adjusting the first 4 voltage ranges, starting at +6%, tapered down to +1.5%, with the rest staying at the 100% mark.

I need more than the short 15km run home to judge, but I think it felt more responsive with that change.

Is there any PFC literature in English that addresses the settings as applicable to piston engines? I've got the RX7 stuff, but there are obvious differences.

cheers

Dale

[paulr33]

yeah the rx7 has PIM voltage table which comes from the map sensor, so the main difference is PIM vs AIRFLOW and rx7 has leading and trailing IGN whereas RB (well piston) has only IGN

[paulr33]

yeah the rx7 has PIM voltage table which comes from the map sensor, so the main difference is PIM vs AIRFLOW and rx7 has leading and trailing IGN whereas RB (well piston) has only IGN

[paulr33]

yeah the rx7 has PIM voltage table which comes from the map sensor, so the main difference is PIM vs AIRFLOW and rx7 has leading and trailing IGN whereas RB (well piston) has only IGN

[paulr33]

oops

[The Mafia]

mmm.. I might have to try this...

[paulr33]

try upping via the airflow correction table? yeah go for it just do it in slow increments, its the same as manually editing the ign table directly just quicker

[Robo's]

Hmm i might try this when i get home. I remember with my last tune i was altering the first 2 voltages to read 85 + 90%. I done this as i had an eratic idle as this seemed the best fix

Edited October 19, 2005 by Robo's