Airflow & fuel cut

[dsm81]

I've searched, but could not find any definitive answers.

Does anyone know what kind of airflow readings trigger fuel cut on a 2G? I've heard anywhere in the 26 to 28 lbs/min range, but on the other hand I've also read that it comes in only after 30 lbs/min. Currently the most I've logged was 26.3 lbs/min. The car was running very good and I haven't hit fuel cut yet. Any ideas? Thanks a bunch!

 

[13secGST]

I honestly don't know...I never had a logger when I was getting fuel cut...cause I went straight to DSMLink...and that got rid of my fuel cut for me.

 

[pickens]

i run about 27lb/min and now I think I'm fuel cutting

 

[dsm81]

Since I've first posted, the most I've logged was 28.7 lbs/min at the top of both 2nd and 3rd gear on a 13.8 sec pass with no fuel cut. Boost was 17 psi to 7K with intake air temps of 77F. Anybody else with 2Gs have any more numbers of airflow for when fuel cut is engaged (without fooling the ecu)?

 

[kpt4321]

No matter what you do to the ECU, the fuel cut will always happen at the same INDICATED airflow.

I bet you're getting very close to it.

 

[pickens]

I have logged a little over 30 lbs/min. My airflow peaks at around 5700RPM and stays almost constant to redline. This is at 19psi. I tried 20 psi, and bam! At 5500 RPM fuel cut hit hard. I have been trying to diagnose my log, and it seems fuel cut is not just a maximum airflow event, but rather its based on RPM as well.

 

[Jaraxle]

Anyone log injector duty cycle at the same time ? I am wondering if 30lbs/min = 100% injector duty cycle on the stock 450's ?
Also, anyone have a dyno chart to go with this information... anyone ? Everything I read says that the 450's are only good for 275hp at 80% or so injector duty cycle. It would be good to know if the stock ECU doesn't fuel cut until it sees the maximum amount of air the 450's can satisfy...

 

[Defiant]

http://members.shaw.ca/costall/ECUprimer/ECU_ch7.html

 

[kpt4321]

That link does not provide any more information that what we already knew.

I agree that it may be based on RPM was well. As such, perhaps the limit is not in lb/min, but rather in airflow per rev. That might explain the inconsistient numbers people (you included) are seeing.


...Kyle T.

 

[Violater101]

I know this doesn't answer the problem, but for me, Fuel cut was around the 270'ish HP range on stock injectors with a Big28 with basic bolt on's w a FMIC. I dyno'd 240@15psi minus the FMIC and a downpipe. After adding those 2 pieces, I experiened fuel cut for the 1st time ..all I had to say to myself is WOW...brickwall!