MAF and MAP discussion..
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MAF and MAP discussion.. I have been playing around with the MAFT setting for NA and N2O runs and have come to the conclusion that along with all the parameters like LTFT,O2,KR,and TM the other variable that really shows you where your optimum setting is. For instance, the MAF truely shows you where you're at relative to the optimum mixture. My NA MAF data produces 31-33 lb/min at 4% rich WOT setting and 33-35 at 6% setting (0 KR both settings). My nitrous runs are producing 37-39 lb/min at 4% (up to 4* of KR) and 34-37 at 6% . My O2's at 4% are .92 (NA) and .89 (N2O), at 6% they are .93 and .90. The goal in this whole event was to eliminate the KR on nitrous...duh, which i did, but what I found from richening during the NA case is that my MAF went up! Pretty simple...more air...more enrichment...no KR..equals more power...which concludes more ideal mixture. Therefore the concept of leaning it to a setting that KR starts to occur and backing it off one click is not correct. In combination with this method one also needs to monitor the max. MAF for the "optimum" setting.
The IAT and Cooling temps need to be pretty consistant to use this method also. It will be interesting to find out if this assumption is right once I get dyno tuned.
Any thoughts would be greatly appreciated.
One more thing...
What can/does the MAP data tell you relative to tuning? I run pretty consistant 28-29 in-Hg at WOT NA and N2O.
The IAT and Cooling temps need to be pretty consistant to use this method also. It will be interesting to find out if this assumption is right once I get dyno tuned.
Any thoughts would be greatly appreciated.
One more thing...
What can/does the MAP data tell you relative to tuning? I run pretty consistant 28-29 in-Hg at WOT NA and N2O.
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Re: MAF and MAP discussion.. If I understand your post correctly you are saying that when you richened your mixture with the MAFT your MAF airflow rate went up - and the conclusion is that indicates you are making more power.
The problem with that is increasing your indicated flow rate is *Exactly* how the MAFT works. It directly indicates a higher read flow at a given absolute flow rate in order to change the air fuel ratio. So when using a MAFT (or altering MAF tables in the computer) you can not use MAF massflow as a power indicator.
The problem with that is increasing your indicated flow rate is *Exactly* how the MAFT works. It directly indicates a higher read flow at a given absolute flow rate in order to change the air fuel ratio. So when using a MAFT (or altering MAF tables in the computer) you can not use MAF massflow as a power indicator.
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Re: MAF and MAP discussion.. SpeedDemon, thanks for the input. I understand your point, but I do feel more pull at the 6% rich setting NA and I get no KR at 2% lean. I just need to get to the dyno to find out where I am at.....
Thanks again.
BTW, what is your take on the MAP data? How can you use it.
Thanks again.
BTW, what is your take on the MAP data? How can you use it.
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Re: MAF and MAP discussion.. Your car may run better at a different a/f ratio, regardless of your indicated knock retard.
I think the point that Chris above was making is that you can't use the MAF rate as a quantification factor for performance when your tuning you are trying to quantify is directly effecting it.
MAP is just a measure of the restriction in the manifold - it is also a good indication of load when you take into account rpm. It's just like using an engine vacuum gauge (in reverse); Barometer - MAP = engine vacuum.
Chris
I think the point that Chris above was making is that you can't use the MAF rate as a quantification factor for performance when your tuning you are trying to quantify is directly effecting it.
MAP is just a measure of the restriction in the manifold - it is also a good indication of load when you take into account rpm. It's just like using an engine vacuum gauge (in reverse); Barometer - MAP = engine vacuum.
Chris
