Tuned With Wrong Afm Help?

[1000AWHP]

This is the story, I recently got my car tuned. I took it home and the car was running weird. I call my tuner right away and he said it was becuase of my coilpacks and said there is nothing else he can do. So I played around with my Power FC and I found out tuner, tuned it with rb25 AFM's causing it to heavily misfire at high RPM's. My car has Z32 AFM's so when I swtiched it on my Power FC. The misfire's went away and the car runs great. I would like to know if my car is possibly running LEAN or RICH and is it safe to be running the car with a tune meant for RB25 AFM's. The car made 302KW on the dyno on 1.1bar, (with MISFIRE). Lastly should I ask tuner to re-tune my car without charging me?

Any input would be appreciated. Thank in advance.

Edited December 3, 2010 by jdm538

[DVS JEZ]

really 302kw on 14psi, what mods?

i dont think i would trust that tuner if he tunes with incorrectly set AFM's.

[1000AWHP]

really 302kw on 14psi, what mods?

i dont think i would trust that tuner if he tunes with incorrectly set AFM's.

1.1bar = 16psi

This is my build thread with parts list.

http://www.skylinesaustralia.com/forums/Gt...ri-t340007.html

I just worried if I am running lean on high boost.

Edited December 3, 2010 by jdm538

[DVS JEZ]

my Bad, sorry, i mis read the boost.

just read the build you went all out, well done, so are the turboes definately -5's? you will need atleast 20 psi to see some big numbers,

What compression did you build the motor too?

[1000AWHP]

my Bad, sorry, i mis read the boost.

just read the build you went all out, well done, so are the turboes definately -5's? you will need atleast 20 psi to see some big numbers,

What compression did you build the motor too?

stock compression, yes they are -5. I was hoping to hit atleast 20psi but he said not to boost over 19psi.

Thanks

Edited December 3, 2010 by jdm538

[DVS JEZ]

did he not want to hit over 19psi due to the miss? do you have a copy of the dyno sheet with AFRs and power curve boost curve etc?

[STATUS]

will need retune, don't boost it much just to be sure.

[paulr33]

fyi if he has datalogit or power excel you can edit the "AFMs" in the powerfc and you can rescale them to your hearts content. ie you can could make the stock BNR32s perform the same as Z32s by copying the ramp values.

its likely this hasn't occured in your case as he would have said that, and the idle wouldnt change when choosing different AFM ramp, but technically with datalogit it is possible to tune with the wrong AFM and edit the ramps. why you would do this, no idea, but it can be done

[1000AWHP]

he used a computer based program I am not sure which one. The car idled perfectly at 1k and everything ran well up until 4k, then the misfire would cause hicups. When he unlocked the Powerfc and switched it to Z32 AFM no more hicups. I asked him if the car is ok with the tune. He keeps telling me air/fuel is good and should be fine if I do not boost over 19psi. I dont know if I should believe him.

I'll post up dyno sheet with afr asap.

Edited December 3, 2010 by jdm538

[STATUS]

fyi if he has datalogit or power excel you can edit the "AFMs" in the powerfc and you can rescale them to your hearts content. ie you can could make the stock BNR32s perform the same as Z32s by copying the ramp values.

its likely this hasn't occured in your case as he would have said that, and the idle wouldnt change when choosing different AFM ramp, but technically with datalogit it is possible to tune with the wrong AFM and edit the ramps. why you would do this, no idea, but it can be done

yup like what i have for nismo afms... cut and paste and hey presto.

like your saying you could cut and paste the z32 voltage table into the std afm table and it should be fine.

in fact you can run any afm provided you have the volt scale, used a few lightning afms in the past on bigger setups.

[1000AWHP]

in your opinions do you think the car would be on the rich or lean side?

Edited December 3, 2010 by jdm538

[paulr33]

too hard to tell, only way is to check on the dyno

if it was tuned on RB25, leave it on that, dont change it then trash it around

your just asking to kill something

leave it how it was, plonk it on a dyno and check the AFR/s etc

[DVS JEZ]

my old tuner set my stock AFMs like above on my old GTR and it made 419KW

if my AFM's max out on my current GTR im gonna try this, much cheaper,

why doesnt everyone do this instead of buying Z32's? i understand the sizing difference of the body but surely the sizing of the stock AFM's could handle pretty big power.

[paulr33]

ah it doesnt quiet work like that, when you hit 5v on the AFM, you hit 5v and it cant physically measure any more air

there is a difference between running out of load cells and maxing the AFM (5v).

when you hit the 5v limit you have two options

a) replace with higher flowing unit

b) pan out the cells as best you can run be stuck with a 1d tune (map sensor style) when you peak the AFM - your only load increase axis is RPM

you can't edit the powerfc settings to make an AFM that hits 5v, magically only reach 4v to "overclock it" or "rescale". recale only affects load rating

[1000AWHP]

I am talking with my tuner tomorrow I hope he retunes my car on the dyno without charging me. He just kept telling me my fuel and timing is fine and I shouldnt worry. After hearing your opinions I think I will have another talk with him about my tune.

thanks everyone

[DVS JEZ]

Also try sone new plugs gapped at .8mm if u havent already. Hopefully that will fix the misfire

[1000AWHP]

I will be retuning the car this week. Is there anything I should ask or tell the tuner?