ok i am gonna do a KLZE swap and i understand that alot of you guys use the K* ECU on a ZE, but it runs rich. I understand y cause the injectors are not calibrated to that ECU.
So my question is If i put the stock K8 injectors in with the ZE and use the K8 ECU, would that solve everything...or will this not work?? I just don't wanna try to run the car if its dumping lots of fuel in the cylinders.
I am trying to find A KL-31 ECU, but this is just something i would do to get the car running decent with the K8 setup.
Thanks
-Devin
K8 ECU Tuning
-
masterklze
- Junior Member
- Posts: 14
- Joined: June 17th, 2005, 1:52 am
The K8 injectors will not flow quite enough fuel for a KL-ZE. Their normal operating range according to the factory service manual is from 128 - 160 cc/minute, which would only be good for between 144 hp at 80% duty cycle and 180 hp or so maximum. I am presuming here that the lower of the two figures given by the manual is the 80% duty cycle flow rate and the higher figure is the maximum flow rate for two reasons.
First, because 128 cc/min is 80% of 160 cc/min, which seems just a little too coincidental, and second, if the 160 cc/min figure is the 80% duty cycle flow rate, then the stock injectors would support up to 225 hp - I find it hard to believe that Mazda would over-spec the stock injectors by 100 hp!! For those who may not know, 80% duty cycle means that the injector is active 80% of the time - this is the generally accepted maximum duty cycle you would want to run on a daily-driven vehicle.
The stock KL injectors apparently range from approximately 180 to 220 cc/min (maximum), which would mean an 80% duty cycle rating of about 162 - 198 hp, which is the range of hp one finds on stock KL motors.
If you run a K8 ECU and VAF with KL injectors, it will run rich because the ECU will operate the injectors presuming their output is 160 cc/min, when in fact they are 12.5 - 37.5% larger. The O2 sensors will then detect a rich condition and instruct the ECU to pull back fuel at part-throttle, though the range will not be large enough to entirely compensate for the difference in injectors, meaning that at part throttle you will run a bit rich. At full throttle, the feedback from the O2 sensors is largely ignored by the ECU, and the injectors will be dumping fuel at a rate 12.5 - 37.5% higher than expected.
If you use an adjustable fuel pressure regulator to lower the fuel pressure, the injectors may not operate properly. If they are able to operate at these lower than normal pressures, you would need to drop the fuel pressure down to 37 psi for the 180 cc/min injectors, or 31 psi for the 220 cc/min injectors. Again, though, I do not believe that they will operate properly at such low fuel pressures.
A better option would be to use a KL-DE ECU, VAF and injectors. The VRIS activation points will not be correct for a KL-ZE, but then again neither would those on a K8 ECU, and at least the KL-DE ECU and VAF are calibrated to work properly with the larger injectors.
If you do manage to get a hold of a ZE ECU, you apparently should use the K8's VAF, as it is the same as the KL-ZE's. You would need to use the ZE's injectors though...
First, because 128 cc/min is 80% of 160 cc/min, which seems just a little too coincidental, and second, if the 160 cc/min figure is the 80% duty cycle flow rate, then the stock injectors would support up to 225 hp - I find it hard to believe that Mazda would over-spec the stock injectors by 100 hp!! For those who may not know, 80% duty cycle means that the injector is active 80% of the time - this is the generally accepted maximum duty cycle you would want to run on a daily-driven vehicle.
The stock KL injectors apparently range from approximately 180 to 220 cc/min (maximum), which would mean an 80% duty cycle rating of about 162 - 198 hp, which is the range of hp one finds on stock KL motors.
If you run a K8 ECU and VAF with KL injectors, it will run rich because the ECU will operate the injectors presuming their output is 160 cc/min, when in fact they are 12.5 - 37.5% larger. The O2 sensors will then detect a rich condition and instruct the ECU to pull back fuel at part-throttle, though the range will not be large enough to entirely compensate for the difference in injectors, meaning that at part throttle you will run a bit rich. At full throttle, the feedback from the O2 sensors is largely ignored by the ECU, and the injectors will be dumping fuel at a rate 12.5 - 37.5% higher than expected.
If you use an adjustable fuel pressure regulator to lower the fuel pressure, the injectors may not operate properly. If they are able to operate at these lower than normal pressures, you would need to drop the fuel pressure down to 37 psi for the 180 cc/min injectors, or 31 psi for the 220 cc/min injectors. Again, though, I do not believe that they will operate properly at such low fuel pressures.
A better option would be to use a KL-DE ECU, VAF and injectors. The VRIS activation points will not be correct for a KL-ZE, but then again neither would those on a K8 ECU, and at least the KL-DE ECU and VAF are calibrated to work properly with the larger injectors.
If you do manage to get a hold of a ZE ECU, you apparently should use the K8's VAF, as it is the same as the KL-ZE's. You would need to use the ZE's injectors though...
-
jschrauwen
- Forum Moderator
- Posts: 6052
- Joined: September 27th, 2003, 2:01 am
- Location: Frankford, Ontario, Canada
- Contact:
