evovette

iTrader: (3)

I have been playing with getting my fuel trims in check. From the logging I have done I noticed that my LTFT low and LTFT mid in mitsulogger are +10%. I have used ECUPlus to add 10% fuel in all my low throttle driving and at idle. With this change my fuel trims are now LTFT low 0% and LTFT mid at 1%. So on to my question.........In order to have the ECU do this internally (ie with a flash) I planned on reducing the injector size by 10%, my thinking is this would lengthen the IPW resulting in a bump in fuel ( I realize this would richen the rest of my map) Now is this the way it works or do I have it backwards? Also part 2 of this question is, will this cause my injector duty cycle to increase during WOT? Im at 89% now but this is 89% of 513cc so If I scale them down 10% I must also increase the IDC as well right? Im having trouble rapping my head around this simply because the injectors are still the same or is it the fact that the ECU only has a certain range it can use ( in other words 0-?? milliseconds ) therefore it would cause 110 % duty cycles ( or some such higher number)

MalibuJack

iTrader: (5)

Yes, lowering the injector scale, will "Richen" the overall fuel curve (lengthen the IPW)

Keep in mind this will likely need to retune your maps too..

Also, the Injector Voltage Latency value can be used to increase/decrease the IPW slightly (Since it compensates for dead time at different levels of voltage) keep in mind that this setting will have a greater impact at higher RPM than it does at idle.. So it takes trial and error, but you will be able to get it the way you want.

evovette

iTrader: (3)

I dont mind retuning the overall map, Im trying to get my driveability back. I have a vendor flash and it rocks at WOT, it is lacking in the 90% area where I do all my driving. I have been tweaking the map for a couple of days with ECUplus in low loads only and have got the car to drive like stock again at low throttle ranges over the course of about 300 miles. and 2 hours of idle time. So I think I have gathered the right amountof data. In order to be on the safe side I have flashed the car back to stock so I could start from a "safe" point. It amazes me how much cams and an intake throw off airflow at low RPM.

MalibuJack

iTrader: (5)

Yeah I find that I'm bouncing between injector scaling, and adjustment on my MAF (blowthrough MAF electronics) to try to get the MAF frequency at 21psi with my 35r to a level that I would expect.. Only there is very little data from others about what this value should be since most people just give up on the ECU and run a standalone with speed density which is not an option for me..

My car has amazing drivability right now, but the MAF frequency I'm seeing under boost is around 2700hz at 21psi at 5000rpm, and that seems a bit high...

l2r99gst

iTrader: (2)

Jack,

If I can find some time, I should be able to grab some logs from the DSMLink boards with that data. At the very least, it will have the Hz of the 2G Maf, but the DSMLink guys have the calibration numbers for a 2G to Evo Maf conversion, so the 2g numbers should be good data, too. That is, if people logged the frequency...since DSMLink logs mass airflow, that's what 99% of people log.

Although, I remember a post in here, I think by awdgsx, that posted the Evo's Hz value to a mass airflow. If you find some 35r logs with mass airflow, then you can use his chart to get a rough estimate of what the MAF frequency should be.

Although, at 21psi and 5000 RPM, I would imagine the Hz values to be pretty close between a 35r to even a stock turbo. Obviously at a higher boost and higher RPMs, the numbers would diverge significantly, but at that boost and RPM, they should be close. Both turbos should be relatively in a good efficiency range and the engine should be at approx. 100% VE at 5000RPM. 2700 Hz does sound too high, but tuning your Mas to be accurate will be a double-edged sword, which I'm sure you're aware of. On one hand, your drivability is great and everything is working fine now, but you know your numbers are off and you can't compare your data to anyone else's. But, if you start changing things to get accurate data, then you may have to retune the entire airlfow range once again.

Either way, I hope everything works out.


Eric