Road tuning your R33 with PFC. How do you work around a PFC?

[R33vit]

Your right there Matt. Iv adjusted the idle @ 14.7:1 and reset back to closed loop with fair results. I am how ever pinging at around 3600--up. Have chased it out all the way up to 5600 but is a real pr1ck to do on your own.. I'm due for the dyno this Saturday. Maybe easier than on the road.

[Steve]

I have had hunting and it has always been caused by lean mixtures. ie 16:1 being the center instead of 14.7:1.  

I dont know what my mixture are, but to smooth my idle out I just kept pulling fuel and adding timing - the richer I go, the more prone it is to hunt?

what map settings do you have for ign and inj in the first 5x5 cells? if you have time to check them:)

[Revhead]

Can you use the O2 sensor (or some other method) to read AFR's? If so, what voltage = what AFR?

I wouldn't mind doing some road tuning, but have no idea what my AFR's are (guessing

[TomR33]

You need to use a wideband 02 sensor, not the stock sensor that all Skylines have.

Have a look here for some more info: http://wbo2.com

Tom

[EnricoPalazzo]

Matt thanks for the info: WHY are u using a stock 33 ecu?

[BOOSTD]

Matt thanks for the info: WHY are u using a stock 33 ecu?

sold mine, moving up

[EnricoPalazzo]

ohhhhhh

[BOOSTD]

I dont know what my mixture are, but to smooth my idle out I just kept pulling fuel and adding timing - the richer I go, the more prone it is to hunt?

what map settings do you have for ign and inj in the first 5x5 cells?  if you have time to check them:)

The first five cells I try to keep very similar(Ign)( no more than 18degrees from 15). I found with my 264 cams the richer i go the more stable idle is. The car wants soo much more air to idle that the idle up screw is all the way out and I had to re-adjust my throttle stop screw aswell.

[Steve]

sh1t, I am running between 34 and 36 degrees:) and fuel is between 0.988 and 1.004. I have found any more fuel and she doesnt like it - still a bit rich though.

got the AAC valve all the way out too, but found by setting the TPS to 0.60V it was happy, didnt mess with the throttle stop.

[BOOSTD]

Jeeze- heaps of timing, I'll have to see what mine likes. I only started playing with my idle last night. I was refering to my standard cams in regards to hunting.I drove to work this morning and it sat on 2000rpm all the way... not cool lol. Love the sound at idle with the cams, it sounds so tuff. you can feel each individual explosion in your chest.

[Steve]

2000rpm? lots of fuel? you dont have a vacuum leak do you?

[jnr32r]

Anynoe know what the temperature correction actually does?

I was playing around wtih mine and it actually idled smoother once i turned up the correction for +80 to 1.15 instead of 1.00.

[Steve]

Temp correction AFAIK, corrects amount of fuel being delivered - similar to a choke function, so the car will idle on warm up.

If you find it idling better on 1.15, perhaps you need to adjust the maps? Raises an interesting point though, why does the power fc allow correction at full operating temp?

[BOOSTD]

2000rpm?  lots of fuel? you dont have a vacuum leak do you?

Nah I just adjusted the idle stop screw to much which made ALOT of difference on warm up. Is all sweet now =)

[R31 POWER]

First see if you are running closed loop or not, in ETC, under FUNCTION SELECT. It can be enabled and disabled in the same way knock warning is.

Is it best to leave it on or off for normal driving?

[GunMetalR33]

If you car is tuned at low rpm for cruzing and saving fuel the turn it off. If you have a normal tune then you should leave closed loop on so that the computer can make fuel corrections on the fly and save you fuel. If your oxygen sensor is old and dirty then closed loop will screw your fuel consumption...

[R31 POWER]

I should of asked this before to,Is it best to have it on or off if tuning it?

[R31 POWER]

I've read some people have probs with the PFC causing hunting at idle and mine is doing it.My AAC valve worked fine before all of the mods but now it sometimes hunts and stalls if i give it a rev or slowing down,Same if you have a atmo venting BOV.

Also if a back off sometimes it's like someones blipping the throttle WTF is with that?

[The Alchemist]

just a note to expand on Steves detailed post on tuning for economy......when doing the cruise set up at 50kpm, 80kpm & 100kpm at light throttle on a level piece of road the ignition can by set fairly high. I have my PFC at about 38 degrees at these points. This also enables you to run a nice lean mixture which further increases economy. Be careful to pull this timing out quickly though as load increases. The base maps will do this anyway but I'm just explaining why. The PFC pulls out 5degrees timing, hard coded, when you plant it anyway to help guard against detonation, this is non adjustable as for your own good anyway.

Also when the car is coming on to boost is when you start to aim for 12 to 11 :1 AFR on the wideband. To be more precise when your boost meter reads "0" (atmospheric), say on a medium hill holding a constant speed, you should aim for 13:1 ish. My GTR base map had 14.3:1 at this point and was a slug coming on to boost as a result!

Once boost is heading towards4 to 6 PSI aiming for 12.3 to 12.5 :1 is appropriate.

Once boost is up around 10 PSI you would want at least 12.2 to 12 :1 ....anything over 14 PSI 11.8 up to 11:1 is a must!

These are quidelines for the tune it yourself person, to get the best out your car a dyno tune is a must as differences of 0.2 of a AFR can make a big difference to torque and this can only be seen on a dyno graph. But as you can see the AFR increases gradually with boost until you reach the "best" figure for your car which could be anywhere from 12:1 (fairly lean at boost ) to 11:1 (fairly rich at boost but nice and safe)

hope this helps

Mike

[Steve]

R31 POWER, do you still have the mesh on your AFM? both sides? Also, check your fuel cut recovery rpm, and you could try adding a couple of points to the fuel around idle.