Problems With R33 Gts-t

[Finny]

Hi all,

I am having a few issues with my R33.

When I plant my foot and rev it to about 5000rpm the car will pop flames like its running REALLY rich and as it continues to rev to 7000rpm the pops happen more and more.

so basicly you know when you back down a gear in a car with a big exhaust and it burbles and pops flames well mine does that but more vigourisly while I am driving it hard.

I leaned it out heaps in the high revs on my SAFC and that seemed to clear it up a little bit but the car started to ping due to being too lean so I had to richen it back up again.

I also notised that my SAFC was displaying 100% air flow at around 5500rpm and onwards... but I didn't think I would be maxing out my air flow meter with the small ammount of mods that I have, any one know what the stock air flow meter is good for?

I am assuming that what is happening is the AFM is reading 100% air flow and the ECU is going ohh crap dump fuel but I just don't understand how I could be maxing the AFM.. I have heard that they are good for atleast 250RWKW and my car is definatly not making that much power but I am running stock ECU with SAFCII.

Any ideas???

Edited September 10, 2007 by Finny

[Finny]

Also a friend of mine has an R34GTT and that made 172RWKW on dyno with very little mods and his SAFCII was displaying 98% air flow at the highest which he thought was a little worrying. When I first got my car with stock side mount ect. I could get it up to about 96% when pulling it hard up a hill in 3rd at around 12psi but now I have FMIC and a few other things the car is easilly hitting 100% AFM in 1st gear let alone 3rd.

I really thing the only way I can resulve this is with a PowerFC... which is anoying because its going to cost me heaps to get it tune up as I live in Tas.

Thing is I can't understand why I need a PowerFC when all I have is stock turbo, FMIC, free flowing 3" exhaust from turbo, pod and thats basiclly it I would assume that stock ECU would easily handle thoes mods.

Coil packs seem fine and spark plugs are iridiums gapped at 0.8mm.

[The Mafia]

Stock AFM maxes out at about 190rwkw - Did this with my Powerfc.

[Finny]

Ok so that means Z32 AFM for me but the problem is, I have an SAFC but not a PFC, I assume you can get a Z32 to work with a SAFC but wont that just translate the Z32 signal into a stock AFM signal then feed it to the ECU meaning the limit will still exist due to voltage range??? I don't really understand it that well.

But I assume I need a Z32 AFM and a PFC... so I am looking at about $3000 to fix this one problem :'(

I might as well add some more money to that and get an RB26DETT half cut and do away with the RB25DET :S

Edited September 11, 2007 by Finny

[BAMR33]

http://autospeed.com.au/cms/A_2424/article.html

This was in a recent thread. It's a really good idea rather replacing the afm you have a bypass around the afm and tune the safc proportional to the new volume of air flow entering the motor.

Edited September 11, 2007 by BAMR33

[The Mafia]

I'm pretty suer a SAFC accomodates the Z32 afm, and can translate the signal to the Factory ECU correctly. So I doubt you'll need a power fc.

But you're going to get a better result with the powerfc anyway. Maybe look into selling your safc and getting a PFC anyway?

[Aif]

FMIC, free flowing 3" exhaust from turbo, pod and thats basiclly it I would assume that stock ECU would easily handle thoes mods.

did u change ur plugs with ur FMIC? my r33 broad minded persontered like a bitch when i had the wronge plugs in after my FMIC install. and i though cars only shot flames when there's no cat in the exaust. may be wronge but its cheaper to check these b4 buy a PFC.

good luck

Aif

[sl33py]

Also make sure it's not just your coilpacks arcing. Take the plastic cover off the top of the engine, drive around hard at night until it's making the noises, then pull over and (carefully) look into the engine to try to see little sparks grounding themselves to the block. If it does it at stationary, it might be easier to recreate.

[joeyjoejoejuniorshabadoo]

I leaned it out heaps in the high revs on my SAFC

i probably wouldn't be doing that without a dyno

[Finny]

I'm pretty suer a SAFC accomodates the Z32 afm, and can translate the signal to the Factory ECU correctly. So I doubt you'll need a power fc.

But you're going to get a better result with the powerfc anyway. Maybe look into selling your safc and getting a PFC anyway?

I know this but what I want to know is say (I dont know the voltage ranges so this is an estimate) stock AFM goes from 0v-5v and 5v is say 500cfm of air now if a Z32 AFM was say 0-5v as well but 5v was 1000cfm then what would happen is if you have a Z32 with a SAFC then when you hit 500zfm the Z32 AFM may only read say 3v but the SAFC converts that to the old AFM singnal so it spits out 5v to the ECU so there for there would be absolutly no difference in cfm limit.

I am just wondering if I am correct in saying this.

ALSO...

AFM bypass, I have known about this for ages but this will also not fix my problem.....

ok I give my self a 50% AFM bypass so that 50% of air is going into the AFM and 50% is bypassing... I set my SAFC to add 50% to the AFM reading. AFM gets to 50% air flow SAFC blows it to 100% air flow and you hit max air flow, You may be able to remove the limit on the AFM but the ECU will still be seeing 100% Air Flow and I doubt that it will have maps for above what the AFM can read so uselss.

Only was I can make this work is by doing this, Getting for example 740cc injectors then doing a 50% AFM bypass and then I wouldn't even need to use my SAFC because the Injectors are pushing 50% more petrol but the AFM is reading 50% less air than its really gettings so that works out perfect. But I think this would screw up your timing etc.

I know some one who has done the AFM bypass as he has a Twin TB NA RB30DE and the AFM only reads on one TB, he also has neerly double sized injectors to match and some SAFC tuning to get it perfect and he only sees around 40% AirFlow even though he is making around 170RWKW.

[The Mafia]

I leaned it out heaps in the high revs on my SAFC and that seemed to clear it up a little bit but the car started to ping due to being too lean so I had to richen it back up again.

holy shit, I just read this - this is madness. Your engine will die!

You need a Wideband o2 sensor and also need to know what you are doing!

[EVL-R33]

Stock AFM maxes out at about 190rwkw - Did this with my Powerfc.

hmmm, i got a stock afm and im making 233rwkw with an SAFC II and HKS 2530kai turbo..