Kioller

Ok i know the title sounds pointless. but i have a vafc, and i set the vtec for 4700 instead of stock 5600 on my d16z6. only problem is that i have to decide how much extra fuel is fed between 4700-5600. does anyone know what % increase it would be in the fuel, or where to find it. i searched the forums, and the internet hates me. thanks

Fabrik8

You're a little on the low side for VTEC on stock cams, and you'll probably lose a little power. Open too early and you're not getting good flow for your intake velocity, and power suffers.
The least you should do to tune with a VAFC is to get an air/fuel meter or a wideband O2 sensor and meter. You really shouldn't be blindly gambling with with your fuel setup, it's just not a good idea. You change your vtec RPM and you may be totally erasing any power gains by guessing what to set the fuel for.
This all really depends on what you have for mods, if you're fairly stock than you're not really going to get any gains from a VAFC unless you're on a dyno where your tuning can be verified. Even then, you're only looking at a few HP on a stock D16.

Kioller

yeah, i have all of the fuel settings at 0(no change from stock). i can feel it pull harder at 4700 with the vtec so its more power, i just need to know the stock fuel difference. i do understand that whatever mods i have| full exhaust(4-2-1 header, 2 1/4 piping to 2 1/2 magnaflow), adjustable cam gear, cold air intake, will change things a bit. but its just bolt ons really. thats why i jsut wunna know when the ecu reads 5600 and hits vtec, it adds fuel(obviously) i just need to know that percentage increase, so i can type it in. i cant seem to find any specific fuel maps online, its odd i use google. thanks

Fabrik8

You have to grab a ROM editor somewhere to actually view any maps, and then you'll have to calc the fuel increase according to the injector size and duty cycle. Fooling the ECU is a bad idea, which is why I hate VAFCs. Anyway, I'll try to get you some relative number you can dial in, I'll take a look at a stock P28 program and compare the low and high cam maps. It's sketchy at best, but it may work. You'll have to dial in the ignition changes too.

DORKO

raise your vtec engagement you actully gain horse power...make it 5900ish or somehtign

sk8rmike

Not true.

Fabrik8

Usually it just feels like you gain HP if you raise your VTEC RPM. The higher you go up in RPM on the low cam, the more power you drop, so when VTEC engages it's more dramatic when the power picks back up. If vtec is set properly it's almost completely invisible, there won't be a noticeable transistion at all because the high and low cam power curves intersect the right way.

PM me your email address, I just totally hooked you up and made a spreadsheet with the P28 maps in it for you, all 4 of them. I can't attach an Excel file here, so I have to email it.