Enlightened

Gernby,

Can you be more specific as far as the concerns? I was just out driving and was testing partial throttle and it felt as if it was like the stock VTEC engagment, but lower. This is just from my driving experience, but I lack the technical knowledge that some of you folks have.

Please enlighten me. = )

Erik

Chris S2K

It is possible to add two VTEC engagement points. A knowledgeable tuner in New England also tunes that way with the Greddy EMU. I'm not sure if the Apexi Neo is capable to tuning this way, but I don't know how else to explain the dips in your dyno - it's best to ask your tuner as he will have a definitive answer for you.

Gernby

As I said, I'm not familiar with the NEO, but with any piggy back, you don't want to do any fuel tuning when the ECU is in closed loop. If you can't tune, then you really don't want VTEC engaged. If VTEC engages without the OEM ECU knowing, and it's in closed loop, then the short term fuel trims will be applied to correct the AFR. This will also be applied over time to the long term fuel trims, which are applied ALL THE TIME, whether it is in closed loop or not. This will throw off your tune, and cause it to run rich or lean at full throttle. Basically, not a good thing. This is the type of thing that makes people who don't have their VAFC's setup correctly talk about the ECU "learning how to untune" their tune.

If the NEO lets you set a threshold where VTEC only engages below the stock RPM if above X throttle position or MAP voltage, then you're probably fine.

s2000Junky

gernby, I appreciate your insight, but maybe you should help out on a subject your more familiar with rather then speculate and share your vast experience in other areas that don't pertain here. I'm sure there are some other threads where you could flaunt your knowledge and have it be helpful. I've been tuning/using the vafc2 on my own previous N/A set up and now SC set up for 4 years now, I know its strengths and weaknesses well. Other then some cool new graphics and a few more fuel set points, the neo is the same unit.

So we are talking about the vafc/neo here, and what your and now the op's concerns are with the transition from partial throttle into vtec. I'm here to put the OP to rest that this is not a concern, I can say this becuase I understand the mechanics of whats happening during this period and what can be expected. And as I stated before there is no such thing as multiple vtec engagement points on this device. If the OP had some specific questions about the AEM EMS which I don't use, then I wouldn't bother to chime in, I've got better things to do

myslow1

nice gain over stock. I would not worry about where you have your vtec engagement point set. Mine engages at 4800 as thats what worked the best and I am also running an afc neo. Assuming your afr is good i wouldnt worry about it

and yes no such thing as multiple vtec engagement points.

Gernby

I looked in the NEO user manual (on Apexi's web site), and it turns out that it DOES allow you to create a VTEC window based on throttle position, manifold pressure, and RPM. If your settings are correct, then your VTEC will only engage at 4500 RPMs if you are at WOT, not partial throttle.

Junky, I aplogize for the offensive tone of my post about your first post, but I have quite extensive experience with the VAFC and similar units. The fact that I also have experience with the FlashPro just lets me know how dangerous VAFC type devices are. Frankly, everything you said in your first post to "clear things up" was incorrect.

Gernby

Not true. There absolutely is such a thing as multiple VTEC engagement points. It just isn't a feature supported by the NEO.

chenpo

Nice gains with just all that. You think I would gain anymore whp if I was to change ignition spark and have oil catch tank, and ap2 coil packs on my ap1. I'm push 208whp. Tuned by enginetiks. They where pretty good.

s2000Junky

Incorrect? I don't think so. The vafc2 has a set up option for vtec throttle position engagement too, but it does not intercept the proper s2000 ecu signal pathway to use this feature, but you wouldn't know that since you don't have enough experience using this unit to discuss it. The vafc does work on other cars, some of the features it offers are designed to work on some models and some not, some were even meant to work and don’t, especially if you throw in the variable of aftermarket pnp harness which about 3 different companies make for this unit. I'm not going to continue to get in some sort of pissing match here because you seem to have some form of complex. Feel free to post what you like...but if your stance is trying to somehow discredit what I’m saying, someone who clearing has some insight into the situation through experience, to make your offering somehow more sound or substantial, then you already lost your battle.

s2konroids

VAFC2 are not dangerous as such their weakness is effecting ignition timing inadvertently (not being able to adjust) and their abilty to tune only on MAP and RPM as opposed to a standalone method with TPSxMAP etc tables. I will refrain from jumping into lots of jargon.

What you will see/feel is the stock vtec engagement point will feel stronger because of the stock ignition timing advance of the factory ECU coupled with the stock VTEC engagement rpm point.

I can see where your coming from regarding learning, however the stock ECU can not learn in WOT, when rolling from partial throttle to WOT to and from it could be possible. Partial throttle it will learn.

Of course you are correct the stock ECU will not know it is in vtec at 4500 (set by the Neo) and this could have potential problems, hovering around.

I also have experience of tuning standalones namely DTA and VAFC2 (or piggybacks) too .

I will say a VAFC2 will never compete and perform as well as a flashpro/standalone ECU, but as a basic device its not too bad.