Vafc2 installed
03-05-2014, 09:13 AM
#11
Originally Posted by s2000Junky' timestamp='1392069069' post='23008867
[quote name='CoolGuy094' timestamp='1392065292' post='23008718']
The Apexi AFC Neo is the first (of the VAFC line) to introduce VTEC engagement based on throttle position. Hi>Lo, Lo>Hi settings are the same, but now there is a throttle percentage value set as well such that VTEC will only engage if you are over that certain throttle percentage at the changeover point.
If you are consistently having issues with cruising in VTEC based on your driving habits, it may be worthwhile to upgrade to the Neo.
The Apexi AFC Neo is the first (of the VAFC line) to introduce VTEC engagement based on throttle position. Hi>Lo, Lo>Hi settings are the same, but now there is a throttle percentage value set as well such that VTEC will only engage if you are over that certain throttle percentage at the changeover point.
If you are consistently having issues with cruising in VTEC based on your driving habits, it may be worthwhile to upgrade to the Neo.
To the OP, you still run into the issue of not being able to add fuel though (only subtract it) so the VAFC line up still has a major compromise. You can use a adjustable rate fpr to increase fuel pressure to get around that though, then fine tune the fuel curve by subtracting the areas not wanted with the vafc. I think the NEO has an even higher fuel point resolution over the vafc2 for more fine tuning.
You will run lean in the fuel map between the stock vtec rpm (5900) and the new lowered rpm because the ecu thinks you are still running in primary cam, so you will want more fuel in that range at min.
What should tge target afr be ?
[/quote]
In my experience NA and SC the best transition area where the car made power is between 3500-4k rpm, a TP is crucial in making this work. If your still running a cat you wont be able to make any power in vtec bellow about 5500rpm.
With the SC I always tapered my afr to run leaner at a lower rpm where there is minimal boost/strain and where the added trq and responsiveness of the leaner afr is appreciated most. So generally Id run 12.8-13 range up to about 4000-4.5k rpm and start introducing more fuel progressively till I hit 11.8-12 at redline. It should be noted, the leaner the afr the higher the combustion temps will be, and the richer the fuel ratio the cooler, but an extreme on either end can cause bad problems so there is a safe range and you can choose to run on the richer or leaner side of that range depending on some general factors. Generally 12 afr on the nose is a good safe and efficient afr target to aim for in any set up that is timed properly and AIT are in a reasonable range. But if you want to maximize the efficiency and safety, again leaner can be had in the lower rpm and richer is safer for the top end where the engine is producing more heat. The factory s2k fuel map is actually tailored this way, this is most evident in the earlier ap1 years.
General afr theory states that max trq is made at 13.2:1 ratio and max HP at 12.5:1.
05-15-2014, 10:28 AM
#12
So with an OBD scanner you can get Fuel Trim Bank sensor readouts, theoretically could one use this data to fine tune a VAFC?
Or is that data not valid at WOT? Trying to understand.
Or is that data not valid at WOT? Trying to understand.
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