| Author | Message | ||
     Ericz |
Have any of you seen these parameters/tables with values other than what is in my image? I know that the 1125 models have a MAP sensor installed and wired up but I have not come across any 1125 tune that has this function enabled. I am working on a special turbo XB tuning project and would like to learn if there are any factory ecms that utilize these values:  | ||
| Stimbrell |
Have checked my 2D ECM and the answer is no, they are all as shown above. | ||
| Ericz |
Thanks Stimbrell! The screenshot above is from a BUEZD eeprom. I know the 1125s come with MAP and Baro sensors installed from the factory but can't determine how the MAP sensor is utilized based on any of the eeprom data from any 1125 ecm. It's so confusing! If anyone knows the significance of the MAP sensor and how it is represented in the programming as seen using ECMSpy for Mono or TunerPro RT, please let me know  | ||
| S21125r |
Ericz - I too am confused as the TP to Load table seems to indicate that the system is Alpha-N driven. I did see a few Airbox Pressure Sensor Configuration settings in the Flags section so my first thought is that the MAP is used to correct for ram air... but most of the settings are disabled or contradictory with that thought. Seems to me the old ECMSpy tuning guide had a case study on what HW hacks and SW tweak were needed to make pressure compensated fueling possible on a turbo XB. I'll look around and see if I can find a copy of that. | ||
| Ericz |
Thanks S21125r! Yes, I have the ABP function enabled on my DDFI-2 ecm for my turbo XB. It works great for fuel compensation under boost but there is no ability to adjust ignition timing. I was hoping to be able to utilize the MAP/Load functions of the DDFI-3 ecm with my XB but it seems as though the MAP sensor reads are only setup for the 36-2 crank trigger used on the 1125 motors. The MAP sensor signal does not work properly with the DDFI-3 ecm setup for the XB crankshaft or camshaft sensor. I have done a good bit of data logging to verify it. I'm still looking into it but I'm pretty confident that I can't use the MAP sensor input with my XB. I may be able to get the Baro input to do what I want but there is more research to do. | ||
| Ericz |
As for the 1125 programming, it looks as though the ecm is setup to run Alpha-N but have all of the settings in place for the MAP sensor functions to be easily enabled. It would make sense for the factory configuration to have as few differences as possible from any "Race" or other config that might be used by EBR for track/testing applications | ||
| S21125r |
Yes MAP does do some amount of correction for spark. A few years ago I was trying to identify the cause of the low RPM lurch that most stock 1125 have. As soon as my bike went into it's lurching routine I could see both the MAP reading and Spark Advance reading oscillate wildly until the lurching stopped. I also set up logging so that it mapped advance as a function of TP and RPM expecting it look pretty close to the base timing table with some global correction for conditions expected. Wasn't really the case as advance varied quite a bit for any particular TP/RPM cell. How the ECM does timing corrections is a mystery to me as I don't recall seeing a whole lot of tunable variable for it in Tuner Pro. | ||
| Ericz |
Interesting info, S21125r! From what I have determined I would think that your low RPM lurching would be the cause for the MAP signal to oscillate, and not the other way around. Did/can you check those logs to see the IAC position during the lurching? If the throttle position is constant, it may be the IAC which is the cause of the varying manifold pressure. | ||
| S21125r |
I'll have to dig up my logs from my flash drive when I get a chance - it hadn't even occurred to me to check IAC during the lurching condition. Knowing that the base timing on the stock ECMs were overly advanced, my original hypothesis was that a little bit of drive line slack initiates it all and then the resulting load/no load gets the MAP cycling enough to screw up the timing which introduces more slack and surge into the drive line in sort of a run away fashion. Now I'm starting to wonder if that particular RPM was right on an IAC step or something. I'll dig up my logs and have a look - been a few years since I looked at this. BTW - what kind of turbo you running? I had an Aerocharged S2 for a while but sold it to a bud of mine down in Alabama about 4 years ago. Loved the Aerocharger in concept, but the variable vanes on that thing were way too delicate. | ||
| Ericz |
I'd like to hear what you find from the logs. I'm running a Garrett GT22 turbo with an external wastegate. The Aerochargers are really neat but you are right about the vanes! | ||
| Zac4mac |
When I first got hold of the infamous Dave from Ohio software, I retarded idle advance from 17˚ BTDC to 5.5˚ BTDC. I had been dealing with extremely harsh low speed performance I had with Loretta in the early years... That one mod had a huge impact. Immediately after dropping the advance I saw cooler headers(no longer white-hot) and much better low speed control. As improved as the outward symptoms grew, the causes became harder to spot. The "under load" maps are good, just not for idle. Loretta is very well sorted now, very excited to see her after the 1190 kit. It's late... will try to upload some PIX tomorrow. Zack |
