Afr Down To 10:1...

[Rekin]

Hey all,

Couple of months ago, i had my car dyno'd and got around 157.3kw atw, with afr around the 11-12 mark.

Mods;

- batmbl front/dump

- xforce hiflow cat

- apexi catback

- ARC 110mm SMIC

- Standard boost - leaking to about 12.5psi~

- Splitfire coilpacks

(here is a dyno scan of 150.3kw, dont have a copy of the 157.3kw run which included a new dump/front + cat)

Had another dyno run today at Swinburn Tafe and confused about the results..

*note; when the car was on the rollers, it was vibrating real badly too, he suggested it may have not been tied down properly or something..

The differences between last dyno and this one;

- New O2 sensor

- Installed a socket into my ecu for future remapping. (Standard chip in ecu, just installed a socket and plugged standard chip back into ecu)

For the past 2 years all my dyno runs have had an AFR reading of 11-12..

Why has it dropped all the way down to 10 resulting in a large loss of power

Thanks

Patrick

[KURAUN]

i think because you have an EMO r32

yes, yes thats it

[Adriano]

If the ecu detected knkock, then it would have reverted to the low octane map, which i richer. Have you tried resetting the scu?

[Rekin]

i think because you have an EMO r32

yes, yes thats it

lol sif, just needs some little assistance

[Rekin]

If the ecu detected knkock, then it would have reverted to the low octane map, which i richer. Have you tried resetting the scu?

hmm you could be onto something.

It could be a result to the problem with my car.

http://www.skylinesaustralia.com/forums/Lu...90#entry4195890

As the car was left to idle before it got onto the dyno it was starting to miss, guess it might have been on safe map as it was run on the dyno?

[VB-]

yeh if the vibration on the dyno was bad it could have been messing with your knock sensor, retarding timing, although i dont think knock detection changes your fuel map?

[R31Nismoid]

Does it blow a nice big cloud of smoke @ idle once warm if you give it 5-10 big quick revs? (depends if your running a cat sorta hehe)

[schtein]

Probaly your o2 sensor that needs replacing. Check with datascan/consult for fluctuations in o2 readings. When o2's stop working properly the ecu reverts to a safety map and dumps more fuel.

'

[Rekin]

Probaly your o2 sensor that needs replacing. Check with datascan/consult for fluctuations in o2 readings. When o2's stop working properly the ecu reverts to a safety map and dumps more fuel.

'

yeah im thinking its my o2 sensor.

When i rev in neutral the o2 voltage doesnt fluctuate. It just stays at a constant voltage.

Although ive heard that o2 sensor doesnt affect the car on full throttle so wouldnt make it run rich?

I'll get the o2 sensor replaced anyways, cause its the only thing which has been changed since last dyno...

[VB-]

o2 sensor shouldnt change ur A:F ratio at full throttle, only light load and low revs