Hello,
I am using 440cc injectors and going to replace to 750cc injectors. My current 440cc are simply to small (I get 100% duty cycle and i would also like to increase the boost)
my reqfuel is 6.2ms and this is my current ve map (currently the engine max load is 180 - with current boost):
(http://img848.imageshack.us/img848/2654/vemap.png)
Should i just remove the reqfuel to compensate or alter all the ve map. The refuel is the easier way but i understand that the resolution of changes is bigger, when changing only the req fuel.
what do you think?
BTW - currently, engine load is 160-190kpa - depends on my boost controller settings. I intend to go up to 230. Rev limiter at 7000rpm. Full boost is around 3500-3600rpm.
Thanks,
If the car is tuned well already, I would just rescale the reqfuel. 440cc/750cc = .58, 6.2ms * .58 = 3.6ms new reqfuel. You may have to "tune" the new injector open time, ramp-up, voltage compensations, etc. to get them to act perfectly linear. From the looks of your map, you didn't do that with the 440's. It's not necessarily a problem, but with proper injector calibration, the map is nearly flat. I have a feeling your in-boost fueling is very rich.
Hi,
Thanks for the reply!
The car is not tuned well. You are right about the in-boost fueling. it is now set on 10.6:1.
But even with 11:7:1, of course, the DC is at 95%. It is not healthy and therefore my rev limiter is at 6K RPM instead of 7K. Until I deal with this.
You were also right about the injectors open time. Originally the map was built for 215CC Bosch injectors. After adding the force induction, i replaced them with new Ford sport 440CC.
I would very much like to learn how to "tune" the injectors. Can you provide a link to relevant documentation?
Thanks
Hi again,
I've replaced the 440cc with 750cc. I indeed used 3.6 reqfuel, but since i also changed to fuel pressure regulator from 3.5bar to 3 bar (to get better idle), i increased the reqfuel to 4.1 and the transition was very (and surprisingly) smooth.
PW in idle is around 1.2/1.3ms (RC injectors) and idle is ok at 950 rpm.
So if i understand you correctly, the values in the VE tables should stay ~identical if i go up in the rpm band, and only change when i move across the engine load axis - if the injectors are tuned?
I removed a lot of fuel and still i get around 0.74 lambda in boost (i am aiming for 0.79 or 0.77) - maybe its because i thought i should increase fuel in rpm axis.
Here is a snapshot of my fuel and timing. I am not sure the timing is right (i think i retarded it too much in boost - just to be safe)
(http://img11.imageshack.us/img11/7435/42062012ve.png)
(http://img137.imageshack.us/img137/3663/42062012ign.png)
I also have some logs of runs, but i guess that if my map is not good enough, there is no point of uploading them, yet.
Thanks.
Make sure your injector dead time is configured right, if it is then no changes should be needed, but that usually isn´t the case. So you will almost always need to make some VE table changes
I am using 1.1.63 - is there a dead time feature there?
current setting are:
opentime 13.2v - 0
rampup 960
rampup voltage compensation - 4080
voltage compensation - 256
There are a lot of fluctuations at light load 2100-3500rpm. You can see it in the ve table :(
I am working on it all the time, taking logs and updating the tables accordingly. At least until i set a dyno day