|
I had another play with the fuel pump PWM output of the e38 today.
As it was putting out 128hz and my fans were also set at 128Hz I gave it a long shot that perhaps changing the fan frequency may also change the fuel pump frequency.
There was no change though. No frequency I entered into the fan pwm frequency had an affect on the fuel pump pwm frequency. So it looks like the fuel pump pwm runs at a fixed 128 Hz.
I wonder if HPTuners has any ability to add a function to change the fuel pump pwm frequency? Fan frequency is available, so what would be so impossible to expect that fuel frequency could also be adjustable hiding somewhere in the e38?
On another note in my playing with the fan frequency I again tried my large frequencies and still hit a 9.33Khz ceiling. Interesting was the fact that at this frequency I noticed the square wave didn't seem to look as clean as the square wave coming out at 128 Hz. I didn't try a bunch of different frequencies to test my theory though.
If I end up using a fan controller that passes through the input frequency to the fans, well then I guess I'll have more work to do on that part because ultimately I would rather be running both the fans and the pump at high frequencies, less audible, hopefully more efficient etc etc...
At this stage I am expecting the Crown Vic clone fan controller I am going to try will not pass the frequency through and simply dump a DC level to the output. As for the fuel pump controller, I bought a Dorman 902-310 to have a play with that and see what I could do. I believe that will pass the pwm frequency through, but won't know for sure until I get my hands on it. If I can't get that to a useable solution then I think I will try a Cytron MD25HV as it uses a fixed 16Khz output and accepts a wide range of pwm input frequencies.
|