RFHOMI2U

Ok, I just sold my V-AFC (version 1) to my friend who has a GSR swap in his Del Sol. The motor is pretty much stock except for i/h/e, and a few other minor bolt ons. P72 ECU, etc.. etc.. We were curious to some people with the same swap how he should map the fuel. Right now it is +2 fuel trim until VTEC, where it goes up to +7 fuel and holds until redline (8200). We set VTEC from 4500 to 5600.

Can anybody give us some pointers on how to tune this? is VTEC too late? too early? what do you guys have for settings on your AFC's for B16A + B18C's???

Thanks....

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pills_PMD

my vtec crossover is at 5100 on my lsvtec del sol.

i use ctr cams, so the fueling was a little different, but i increased nearly 20% after vtec is activated.

how did you set VTEC to come on in an interval?? or do you mean that it comes on at 5600 and off at 4500??

radnulb

I think he means he set it from 4500 to 5600.

With GSR cams, 5600 is *way* too high.
Most GSR cams I've played with like the crossover between 4700-4900 if you are still running the IABs and 4900-5000ish if you are using a skunk2 manifold.

As for your fuel trims, FOCUS. You do *not* need a uniform increase across the board. Fueling should mimic torque. Look at http://www.importreview.com/d_1.8.html an click on a couple of the GSR motors. Your vtec cam will be peaking around 6100 RPM. What does this mean for you? FOCUS your fuel trim increases around your peak torque. Add 8-10% at 6100, and taper down 1% per two hundred RPM until 7100, then 1% per hundred after that as you go up in the rev range. Don't richen things too much - you'll lose power, particularly above 7500 RPM where your torque curve drops off quickly.

Likewise, center the increases you make on your low cam around where the GSR low cam lobe makes the most power.

Good luck.

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PGMFI.org founder and DIY ECU tuning advocate
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