Power FC Negative split ?
02-13-03, 06:35 PM
#1
What's an RX-7 ?
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Negative split ?
Ok Im going to look over the "modified map #9" I just wanna be sure I know exactly how to look for negative timing split, I printed the ign maps then I take the first cell number on the leading map and subtract it from the first cell number on the trailing map, then do the same for all the numbers...is that correct ?
Thanks for any help guys...
JDub
Thanks for any help guys...
JDub
02-13-03, 07:40 PM
#2
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You could do that, or you could go here: http://pb.kenjim.com/pfc/ and click on SPOAutos' map (which is map #9). Scroll all the way down and notice that all the boring work has been done for you.
02-13-03, 08:52 PM
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Thats awesome but that map seems to have some pretty bad neg. split, (-13,-14), how do I fix that just make up numbers where its negative or do you need to change more than just that neg. cell?
Thanks for the help man...
JDub
Thanks for the help man...
JDub
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02-14-03, 05:57 PM
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Really?! what the hell is the deal then? Ive heard from some they werent able to find any power manipulating the timing from base, ive heard from others there was quite a bit of power gains by changing...
02-15-03, 11:04 AM
#9
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Power FC tuning is a "black art" best left up to people with appropriate equipment (lambdo O2 sensor, FC datalogit software, laptop), experience, and patience. Seriously, I also have a couple of negative splits in my KD Rotary dyno-tuned map. I've been monitoring the commander in map trace mode, and the negative splits are in an area of the map where my motor doesn't even go based on my current driving. The probability of hitting those cells are very low. Still--those negative splits are there, and and while the danger is low, the negative splits do present a very low probability of posing a problem given the right conditions.
02-15-03, 11:23 AM
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Thats rigth they are there but if they dont pose a problem thats cool, It just made me think even more poorly about XS engineering to have such large negative splits (-14,-12) !! I still have about 3-4 cells with neg split also but they are only -1, I havent been able to watch the trace mode and wont until spring but I feel comfortable with this.
02-15-03, 12:53 PM
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Originally posted by TwinTriangles
Thats rigth they are there but if they dont pose a problem thats cool, It just made me think even more poorly about XS engineering to have such large negative splits (-14,-12) !! I still have about 3-4 cells with neg split also but they are only -1, I havent been able to watch the trace mode and wont until spring but I feel comfortable with this.
Thats rigth they are there but if they dont pose a problem thats cool, It just made me think even more poorly about XS engineering to have such large negative splits (-14,-12) !! I still have about 3-4 cells with neg split also but they are only -1, I havent been able to watch the trace mode and wont until spring but I feel comfortable with this.
That's how I'm dealing with my negative splits. Other than the negative splits, Dave Barninger's map has performed as he said it would with my street-ported KD Rotary motor, '99 J-spec twins, GReddy Type 24 V-spec FMIC, GReddy Airinx intake, 1300 cc secondaries, Nippondenso Comp fuel pump, Downpipe, Bonez Hi-flo cat, and catback
Boost was set conservatively between 10/11 psi for "Low" and 12/13 psi for "High". Ignition was retarded to make use of the enlarged intake and exhaust ports. Low speed fans were programmed to come on @ 86 C and high speed @ 87 C. Koyo rad keeps the water temps at 85 C during the Indiana winter.
Last edited by SleepR1; 02-15-03 at 12:59 PM.
02-17-03, 12:04 PM
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WOW, I didnt even know that my old XS map was on there. Personally I think the timing on that old XS map of mine is a little advanced in the 6500+ rpms ranges. You might want to turn it down a few clicks.
ALSO YOU NEED TO MAKE SURE YOU DONT USE THE FUEL MAP CAUSE THE BASE MAP WAS WAY DIFFERENT AND YOU CANT GET TO IT WITH THE COMMANDER.
The negative split is in a area that doesget used when under load. I've been told its probably there to help with spool but I dont know if thats the case or not. You can adjust it out by changing the trailing timing.
Good Luck
STEPHEN
ALSO YOU NEED TO MAKE SURE YOU DONT USE THE FUEL MAP CAUSE THE BASE MAP WAS WAY DIFFERENT AND YOU CANT GET TO IT WITH THE COMMANDER.
The negative split is in a area that doesget used when under load. I've been told its probably there to help with spool but I dont know if thats the case or not. You can adjust it out by changing the trailing timing.
Good Luck
STEPHEN
02-17-03, 07:55 PM
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I know you need to retard the timing quite a bit for a street port and my street port is pretty large but I think Im just going to use Suganuma's fuel maps and timing maps just to get me to the dyno and then see what kind of work it needs from there, compared to the base maps his seem quite a bit richer and my mod list isnt too huge I guess... 
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