Hey guys I got dyno tuned about a week back. Finally uploaded the graph wanted some thoughts or opinions. Mods are berk header and test pipe, tuned it with a vafc2 to get it into the high 12s. Any idea why its so bumpy though? Power feels smooth when I accelerate but that chart looks really bumpy when I compare it to others. And thats already with a smoothing factor of 5 (highest)

It seems it was smoother before the tune, but on the baseline before the tune it looks like vtec kicked in twice at about 5200 and then again at 5800. Is that normal?



Sorry for the huge pic

 

deffenitely a rocky curve. to be honest with you i'd take it someplace else. a good tuner will be able to smooth that out, no problem.

 

Is it possible to smooth out the power curve when you can only adjust fuel and vtec engagement? How would that be done?

 

dude af looks screwd...

 

why is that?

 

Your Air/Fuel ratios.

 

Yep. AFR is jacked. You need a better tuner

 

bad tune. Use SAE correction factors, too.

 

You have room to go leaner, your afr's will fluctuate normally but you should be tuning for a range of 13. 13.5. You actually went leaner in your base line pull between 5-6 k which is why it drops off and then picks up again at vtec, but its pretty all over the place. Vafc works great if you know how to tune. Did they drop your vtec at all by chance? Get a wide band and learn to tune yourself, thats a sure way to get the best performance.

You have quite a bit of fumbling going on in your mid range around vtec, I don't see that as much of a tuning issue as I do your ecu getting a bit freaked out by the changing of input signals from the vafc, I have experienced this at times when I make more extensive back and forth changes. Its like the ecu has to go through an adjustment re learn period to make use of the changes it is asked to make sometimes and in the meantime it will run shitty. Do you notice it cut out or miss sometimes in this range or when you ran the dyno? Part of the Vafc fun with our car, I think more so with the older AP1 ecu.

 

Ok 1) I know that AFR is air fuel ratio. I asked WHY is that not what. What about the afr is 'jacked up' exactly.

2) When I said 12s I meant air fuel ratio.

We didnt really mess with the vtec, when we went lower it pretty much stayed the same. The berk header has a secondary 02 bung for wideband tuning, I would get the gauge and do it myself but I have no idea how to work the vafc. And its harder to tune on the street since you cant keep track of your afrs that good as you could on a dyno.

The tuner didnt wanna lean it out anymore because he wanted to leave room just in case.

I chose to go with the vafc2 because I dont have any plans outside of basic bolt ons and I think the vafc2 is sufficient enough for these mods.

When I asked the tuner about the bumpiness of the graph he said that my car was probably bouncing on the rollers when it hit vtec. He also said that his rpm pickup could not be reading correctly. He used the one thats like a replacement coil stick that plugs into your current coil stick, I guess is the best way to describe it.