|Posted on Wednesday, June 12, 2019 - 09:13 am: ||
All - Last year I did a top-end 1050 with cams from NRHS, added an exhaust from Dean Adams along with a stock 2010 XB12 header and XB12 TB, Race ECM. I'm only 150 miles into the break-in from late last season, and recovering from rotator-cuff surgery is delaying this season. It feels like its running pretty rich below 4k - which is expected with the larger, xb12 TB and injectors. it smooths out once the cams come on and the exhaust really starts to sing. Once I get about 600 mi on it, I think I want to dial down the mixture at lower RPM/Throttle position, but not sure where the optimum value would be. I've got a full version of TunerPro, and I've been reading.....scouring the site here for insight. Can anyone point me in the right direction? Joe's Cycle Repair in Mechanicville, NY (about 10 minutes away) has a dyno and I suspect they could do it.....but where's the fun in that? I've got a couple more weeks before I am cleared, so any direction you guys can give me is greatly appreciated. - Sean
|Posted on Wednesday, June 12, 2019 - 10:35 am: ||
Skipbarberman wrote -
It feels like its running pretty rich below 4k - which is expected with the larger, xb12 TB and injectors.
That's (the above) a strange thing to say. Just installing parts has nothing to do with running rich or lean. It's all in the computer about timing and fuel mapping.
It seems right off hand that with the large increase in inches, the whole map would be lean.
And just saying "Race ECM" really doesn't mean anything since there is more than one available, plus has this one been modified in any way ?
As you note, some time on the dyno seems warranted.
|Posted on Wednesday, June 12, 2019 - 11:48 am: ||
Thanks for the reply Mike - I say it 'feels like' its running pretty rich below 4k, because my understanding is the fuel mapping is based on dwell. If that were the case, the injectors are likely larger, as is the intake for an XB12. Therefore, I *assumed* it would be running richer due to more volume, same fuel pressure, same dwell. I may be wrong.
Race ECM is stock '03, no values changed....so I *should* be OK. However, with break-in, it was recommended to stay below 3-3500RPM. It doesn't 'clear its throat' and smooth out until around 4k. Not to get into a 'proper break-in' discussion - much like which oil to use - as long as I vary the RPMs, I *think* I should be fine.
|Posted on Thursday, June 13, 2019 - 10:32 pm: ||
So, can anyone provide any insight or point me to the proper reading - I've looked and seem to be coming up short. Thanks - Sean
|Posted on Friday, June 14, 2019 - 12:34 pm: ||
if you are unwilling to have it put on a dyno with a wideband O2 to see if it is actually running well, you could try some other ways.
I would check the AFV first. That will tell you whether the ECM is trying to lean out or enriched the whole map, and whether you're causing damage by riding it.
Install a wideband O2 and tune it your self by turning off closed loop, datalogging, and running the results through Megalog Viewer. The process can be slow, but will get you very close.
Some say it is possible to try tuning with the stock/ old narrowband O2, but I wouldn't recommend it.
The small increase in cubic inches shouldn't affect too much, but injectors meant for a much larger motor may have issues with definition at lower RPM's just like you describe.