Q45 Afm, Pfc Tuned To Stock Afm

[The Mafia]

Time for me to ask a few questions instead of answering a few..

On the weekend, I am taking off my stock turbo and bolting on a Garrett GT30 with a VG30 ass end.

Through all of this process, I am going to change the stock AFM to a Q45 afm. The ECU I am running is a power FC, and its fully tuned for the stock AFM at 210rwkw..

anyway.. If I plug the q45 in, and set the AFM menu in the powerfc to Q45, fair enough things MIGHT work..

but will it change any over all settings or maps etc?

Will it lean the car out or make it run rich? of course, running rich would be a lot better..

The reason is because my fabricator friend and I are going to make everything up for the car (custom) and want to be able to drive the car 30kms to a tuner to do the full tune.. We won't be able to plug in the stock afm in temporarily because its much smaller to fit on the piping.

hope I have made my question clear enough..

thanks in advance guys

[Sydneykid]

Time for me to ask a few questions instead of answering a few..

On the weekend, I am taking off my stock turbo and bolting on a Garrett GT30 with a VG30 ass end.

Through all of this process, I am going to change the stock AFM to a Q45 afm. The ECU I am running is a power FC, and its fully tuned for the stock AFM at 210rwkw..

anyway.. If I plug the q45 in, and set the AFM menu in the powerfc to Q45, fair enough things MIGHT work..

but will it change any over all settings or maps etc?

Will it lean the car out or make it run rich? of course, running rich would be a lot better..

The reason is because my fabricator friend and I are going to make everything up for the car (custom) and want to be able to drive the car 30kms to a tuner to do the full tune.. We won't be able to plug in the stock afm in temporarily because its much smaller to fit on the piping.

hope I have made my question clear enough..

thanks in advance guys

<{POST_SNAPBACK}>

Not an easy question to answer, but I will have a go.

Selecting Q45 on the menu simply loads the Q45 AFM voltage ramp table. This means the Power FC will have some idea of how much air is flowing through the Q45 AFM by its voltage output. It doesn't change anything else, the fuel and ignition maps are still the same as they were.

This usually enables me to start the engine and let it warm up. Then I see what the exhaust looks like with a few quick free revs.

1. If it is belching black smoke I know it is super rich, so I adjust the fuel trim on the PFC until it just blows a little black smoke. Rememer that the fuel trim resets once you turn the engine off. I then know I can safely drive it to the dyno at low rpms using zero boost.

2. If it is clean exhaust (no black smoke) then I know it might be lean. Again I adjust the fuel trim until I can just see some black smoke out the exhaust. Remember that the fuel trim resets once you turn the engine off. I then know I can safely drive it to the dyno at low rpms using zero boost.

Hope that was of some help

cheers

Edited September 28, 2005 by Sydneykid

[BHDave]

Then you've got the same thing on the ignition side though dont you?

As the q45afm is giving a lower voltage for a certain air flow wont it be looking up a point in the map with more ignition timing than is safe?

[The Mafia]

ahhh I think I just worked it out based of your explainations

if the stock afm is passing through x (normal) amount of air at 1 volt

the ecu puts in y amount of fuel..

if the Q45 is passing z (more) amount of air through at 1 volt then the ecu still puts through y amount of fuel

in the second equation - more air, same fuel = lean

ouch, I better be careful.

Maybe i could adjust the voltages on the q45 afm setting? Have you noticed when you select q45 on the pfc menu, and hit next again, it has options to change voltages etc..

THis is a little confusing. Hopefully I can get to a tuner asap after the modification

Edited September 29, 2005 by The Mafia

[The Mafia]

well, I was just thinking, as even easier way to drive the car around all day every day with this kind of setup, is simply run low boost (5psi or something)

or - no boost at all. Car should be perfectly drivable this way.

[RedRocket]

Maybe i could adjust the voltages on the q45 afm setting? Have you noticed when you select q45 on the pfc menu, and hit next again, it has options to change voltages etc..

THis is a little confusing. Hopefully I can get to a tuner asap after the modification

<{POST_SNAPBACK}>

Yeah, just picked up my hand controller and tried to change mine over to the setting for RB25 AFM's and you hit next and it goes to the voltage screen. I was hoping you could select the actual AFM and be done with it.

Either way, I've driven mine for hundreds of kays with different AFM's and no problems so far.

[hungry6]

It'll drive ok, even with little boost, drove mine like that for 2 weeks before tunes, but it's a different car after tune.

If you"re really worry, get a tow truck, it's $50.00 or about there.

I drove mine around, cause I have nothing better to do.

[Col-GTSX]

My thought are the same as sydney kid....

Its just changes the base voltage maps....

I just check it.... Now i have reset my ecu i thought i may as well play with it.... LOL

[The Mafia]

I installed it but the car runs like puss. You have got to remember that since the AFM is bigger in size, the air flow is now slower.

Hence doing all sorts of weird things to the cars stability.

Need to give it a lot more fuel correction to get it to run stable.

The tuner is going to have fun..