jurn

Had my car to the tuner today. This is a well renown tuner here in Norway. We fiddled for about 3 hours with the car. Tried a richer setup first, but it resulted in loosing a lot of power in the range we adjusted. Then we tried to lower the vtec engagement point. It gave some gains, but the AF ratio was far to lean for my liking (around 16). Tried to use the vtec unmatch function in the VAFC but it was still lean.

So went back to factory settings with vtec engagement, and tried to lean the mixture but that also gave a loss in power. So after something like 20-25 runs we called it a day and went back to stock settings.

And yes, i checked all the initial settings a couple of times to be sure... Everything seems to be working as it should, exept the power.....

Modifications to the care are j's header and TP, Toda exhaust and a spoon snorkel and filter.

So is there something i am missing here, or is it my ECU thats just doing an excellent job ?

Sinji

ecu is pretty good but ive seen mods as high as 20 whp with just tuning...

BlownAP

well having a MY00 should be able to see good gains up top. at the very least + 5whp


I have no experience with euro model s2000s. Might already have a nice fuel curve

D1sclaimer

What whp numbers are you putting down with the mods you have and no VAFC installed?

vader1

Most of the gains from VAFC come from leaning out the mixture, especially above 7000 rpm. There have also been threads about running lean on stock ecu with the J's header.

I am not knowledgable enough about the stock ECU and why it goes lean with a giant header, but I suppose it could be possible that your high flowing header, tp and exhaust have leaned things out enough so there is little to be gained with VAFC. Dunno. Just a thought.

jurn

Putting down 194 with the mods, no vafc. Stock cars usually put down around 185 on that dyno according to the tuners.

attack666

I'd suggest a visit to another tuner.

psileepr

+1

You mentioned lowering vtec and it being too lean. Why not adjust fuel at that point to richen it up till its safe?

Why was your tuner trying a "rich" tune to begin with? Most tuners do a few baseline run and see where the A/F ratio is. Depending on what mods and gas being used they have a target A/F ratio and make adjustments to reach those numbers.

AP1_S2k

^x2 somethings not right with the tuner IMO!!!

bigwhite

dont trust the backsniffer, try to use another wideband at the same time to double check. You might have wrong readings.