VEMS Community Forum

VEMS => Calibration & Mapping => Topic started by: DButters on January 15, 2014, 07:44:46 PM

Title: 13b rotary Bridgeport turbo idle vs cruise issue
Post by: DButters on January 15, 2014, 07:44:46 PM
Hi All,
I have had my car running on my VEMS for some time, and have recently bridgeported the motor.
This is *somewhat* equivalent to a cam giving large overlap and duration.
It results in the most consistent idle being a 3 on 3 off cyclic misfire (brap brap) at ~1600 RPM, and low vacuum (~10 in. Hg)
I get a "good" lambda reading (when it is not in the misfire portion and it braps away happily.

Problem is -
This also happens to be the same load site the car runs through at city traffic speed in 4th gear.
This results in an overly lean condition, I believe because of having the same vacuum as idle (due to overlap from the porting) but actually higher load.

I believe Alpha-N is designed to combat this, but being turbo I dont want to run this completely. Does anyone have any recommendations other than go faster? ;)
Thanks in advance for any ideas!
Title: Re: 13b rotary Bridgeport turbo idle vs cruise issue
Post by: VEMS on January 19, 2014, 09:01:20 AM
Hello DButters,

A combination of Alpha-N with boost compensation is also possible, if you select VE table control strategy = Alpha-N, the RPM/MAP Cor map will also be activated; You can fill Alpha-N map as normally, but also tune on-boost specific part with the fully mappable boost compensation.

More elaboration on this is available in the help pages:

http://vems.hu/vt/help/v3/v3_alphan_settings.html

If there is anything unclear after this, feel free to ask.

Best regards, Dave