G
Guest
·I may be talking rubbish here, but would like to understand something so bear with me and point me in the right direction if I'm wrong please.
After reading loads of posts on the subject of fuel cuts i have read quotes such as...
On fitting an APEX induction kit I have suffered fuel cut recently ......and
My friend has fitted both an after market exhaust system and HKS induction system and has started noticing what seems like fuel cuts under heavy acceleration at 5000 -6000 rpm!.....
I also noticed this interesting post:
You can adjust the calibration on the airflow meter yourself. There is a little screw on the bottom that is covered by silicone.Dig out the silicone and back it out some and the air flow meter registers less air and therefore you postpone fuel cut (you allow more air to bypass the part of the air flow meter that counts the air). The adverse effect is that you also lean out the a/f ratio. Shouldn't be a problem because Evos run rich antway, but it would be a good idea to monitor your EGTs to make sure. This is no less dangerous than the fuel cut defencer and costs you nothing.
It seems that 90% of fuel cuts occur after an induction kit is fitted. The induction kits allow more air to pass thru the Air flow meter housing and the info sent to the ECU is therefore scaled up due to the higher vol of air.
In a naturally aspirated engine, more air into the airflow meter may encourage the ECU to increase the amount of mixture. However, it seems that in a forced induction engine such as our 4G63 turbo units, it seems that the extra air passing thru the airflow meter serves to increase the likelyhood of fuel cuts more than anything. The main increase in air flow comes from the turbo charger as it rams air into the engine.
So why bother with an induction kit ?
If the ECU parameters are not adjusted to acknowledge the extra air flow then all we are doing is unbalancing the system ?
It seems that an after market exhaust makes a nicer tone and reduces back pressure. An induction kit allows more air into the air flow meter but do we really want more air and less back pressure ?
When I replaced the CAT on my car after 1 year of driving without it, I noticed that the low down torque was improved.
I guess that this was due to an increase in back pressure. The reduction in back pressure when the CAT was removed seemed to give a little more pwr up the rev range but less at the bottom end. The addition of the Air induction kit made the car sound better but I experienced fuel cuts. when i remove the rear silencer baffle in my 5ZIGEN exhaust, I experience a shift in pwr to further up the rev range.
Are we not just going round in circles here ?
I drove a friends stock E4 and found that it was much quicker than my modified E4. This E4 may have had the grommet removed in the boost control solenoid and i will be checking to see what the situation is here. But the point is that i have a boost controller|PLS| Exhaust system |PLS| Apex induction kit and run on Super UL. If I pull 1.22 bar I get a stumbling fuel cut during full throttle acceleration, whereas the standard car just pulls and pulls and all on STANDARD Unleaded !!! I am rather confused to say the least.
Mitsubishi has designed an ECU to run our engines at 280bhp approx. They designed the exhaust system and incorporated a CAT. They have mapped the fuel,pwr and torque curves based on a pre-determined airflow reading and carefully calculated the actual exhaust backpressure found in the standard system. The ECU expects all the values to be within a certain predetermined tolerance and then we go and change the balance in a search for more pwr !
Are we improving the car or just buggering things up ?
Comments please !
Jonathan
After reading loads of posts on the subject of fuel cuts i have read quotes such as...
On fitting an APEX induction kit I have suffered fuel cut recently ......and
My friend has fitted both an after market exhaust system and HKS induction system and has started noticing what seems like fuel cuts under heavy acceleration at 5000 -6000 rpm!.....
I also noticed this interesting post:
You can adjust the calibration on the airflow meter yourself. There is a little screw on the bottom that is covered by silicone.Dig out the silicone and back it out some and the air flow meter registers less air and therefore you postpone fuel cut (you allow more air to bypass the part of the air flow meter that counts the air). The adverse effect is that you also lean out the a/f ratio. Shouldn't be a problem because Evos run rich antway, but it would be a good idea to monitor your EGTs to make sure. This is no less dangerous than the fuel cut defencer and costs you nothing.
It seems that 90% of fuel cuts occur after an induction kit is fitted. The induction kits allow more air to pass thru the Air flow meter housing and the info sent to the ECU is therefore scaled up due to the higher vol of air.
In a naturally aspirated engine, more air into the airflow meter may encourage the ECU to increase the amount of mixture. However, it seems that in a forced induction engine such as our 4G63 turbo units, it seems that the extra air passing thru the airflow meter serves to increase the likelyhood of fuel cuts more than anything. The main increase in air flow comes from the turbo charger as it rams air into the engine.
So why bother with an induction kit ?
If the ECU parameters are not adjusted to acknowledge the extra air flow then all we are doing is unbalancing the system ?
It seems that an after market exhaust makes a nicer tone and reduces back pressure. An induction kit allows more air into the air flow meter but do we really want more air and less back pressure ?
When I replaced the CAT on my car after 1 year of driving without it, I noticed that the low down torque was improved.
I guess that this was due to an increase in back pressure. The reduction in back pressure when the CAT was removed seemed to give a little more pwr up the rev range but less at the bottom end. The addition of the Air induction kit made the car sound better but I experienced fuel cuts. when i remove the rear silencer baffle in my 5ZIGEN exhaust, I experience a shift in pwr to further up the rev range.
Are we not just going round in circles here ?
I drove a friends stock E4 and found that it was much quicker than my modified E4. This E4 may have had the grommet removed in the boost control solenoid and i will be checking to see what the situation is here. But the point is that i have a boost controller|PLS| Exhaust system |PLS| Apex induction kit and run on Super UL. If I pull 1.22 bar I get a stumbling fuel cut during full throttle acceleration, whereas the standard car just pulls and pulls and all on STANDARD Unleaded !!! I am rather confused to say the least.
Mitsubishi has designed an ECU to run our engines at 280bhp approx. They designed the exhaust system and incorporated a CAT. They have mapped the fuel,pwr and torque curves based on a pre-determined airflow reading and carefully calculated the actual exhaust backpressure found in the standard system. The ECU expects all the values to be within a certain predetermined tolerance and then we go and change the balance in a search for more pwr !
Are we improving the car or just buggering things up ?
Comments please !
Jonathan