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Title: tuning with a lighter than stock rotating assembly Post by: userpike on June 09, 2013, 10:13:20 PM I would like some opinions/start a discussion on tuning for a lighter external rotating assembly. What I am talking about here is a light aluminum flywheel and aluminum accessory pulleys. in my case a fluidampr is involved also but it's actually heavier than the stock harmonic balancer/pulley.
I'm having a problem when the AC compressor engages, the engine seems like its going to stall but doesn't and recovers quickly. At the same time, the WB shows going very rich then back to stoichish. I figure this part is normal. The same thing happens when the cooling fans are energized with the AC off but not as bad of an effect. I assume it's because of the lack of inertia due in my case, as I've shed about 14-15lbs off the stock flywheel weight plus the lighter accessory pulleys (non underdrive). I'm not sure what maps to change for this. I'd like to get the transition of the accessory's engagement/sudden higher alternator load to be as smooth as possible without raising the idle to 4000rpms ::) Title: Re: tuning with a lighter than stock rotating assembly Post by: nyet on June 09, 2013, 10:19:41 PM Read up on torque reserve...
Title: Re: tuning with a lighter than stock rotating assembly Post by: userpike on June 09, 2013, 10:21:04 PM Title: Re: tuning with a lighter than stock rotating assembly Post by: ddillenger on June 09, 2013, 10:26:47 PM I <3 torque reserves.
Title: Re: tuning with a lighter than stock rotating assembly Post by: userpike on June 10, 2013, 07:57:52 AM Read up on torque reserve... I reread the info in the s4 wiki about it. the link at the bottom is dead What if timing is already retarded 10 degreesish? keep on retarding? or is there something else? Do you think setting KFLDRL to 95%DC @ idle would do the "same thing"? Title: Re: tuning with a lighter than stock rotating assembly Post by: phila_dot on June 10, 2013, 09:18:12 AM I reread the info in the s4 wiki about it. the link at the bottom is dead What if timing is already retarded 10 degreesish? keep on retarding? or is there something else? Do you think setting KFLDRL to 95%DC @ idle would do the "same thing"? No to all of that. You want to look at look at the drag torque and idle control functions. MDVER* and LLR* Title: Re: tuning with a lighter than stock rotating assembly Post by: phila_dot on June 10, 2013, 09:25:16 AM To be more specific, most people get by with just manipulating KFMRES(K).
Title: Re: tuning with a lighter than stock rotating assembly Post by: userpike on June 11, 2013, 08:50:35 AM To be more specific, most people get by with just manipulating KFMRES(K). Thanks a lot for sending me in the right direction. In checking out these 2 maps in an HNbox .kp, I found another I may be interested in but I noticed its Y-axis is different from the other 2. KFMRESKH is the map. Is this correct? In fact KFMRES(K)(NL)(TA) all share the same Y-axis but not(KH) which translates to "torque reserve during catalyst heating" also this map is at 24.9 for all the z values and FFed in the hex dump. I went ahead and transferred the maps after finding their matches in my HSbox file I'm working on. So far everything I have found has been with either having a 164 offset or -3A offset. The 2 files seem pretty close to each other so far. |