I know that with a vtec controller you will not gain any "peak" power, your peak will stay the same.
Someone told me that if you lower vtec you will peak sooner and then power drops off sooner than with the normal setting.
Is this true?
Also, if you brought vtec down to 4k you would see a large gain AT 4k over stock right?

Im so confused...

 

The gains at 4k would be better but you would be loosing the most power you could make through the entire powerband. Generally closer to 4.8k is best. Of course this all depends on your setup and style of driving. Get a tuning shop to help you when setting up your controller, they will help you get the most out of the engine.

 

Not in all cases are you just going to drop the vtec x-over lower and gain power. Yes on stock cams in most cases dropping the x-over a little will gain you some hp but dropping it 1k over stock will actually make you lose power. All in all it comes down to this, you need to fully use one side of the cam before it crosses over and uses the higher end of it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Lone Luder &raquo;</TD></TR><TR><TD CLASS="quote">APEXi VAFC... I haven't gotten there yet, but now is as good of a time as any. The VAFC is something that will help you out tremendously if used CORRECTLY. It controls many things on the back end of the ECU. It helps monitor vacuum in the manifold, full curves, and VTEC engagment. A few things to note about the VAFC:
It'll help you cure some lean spots or rich spots across the RPM band. The only REAL way to use it is connected to a Dyno. Other than this, you're using the *** dyno and that's a good way to screw something up. Also, VTEC engagement... I'll get to that in the cam section, which is next....

CAMS:
Many people think that you can gain massive amounst of power by making VTEC engage at, oh, 3500rpm. Well, you won't. The way VTEC works is by giving the best of both worlds, higherlift cams for up top, with low lift cams for down low. Honda conbined the two and you have both on ONE camshaft.
HOW VTEC WORKSYou have two smaller lobes that the valves ride on most of the time, called primaries. The VTEC lobe is larger and lifts higher but sits in the middle of these two and has a seperate rocker that isn't connected to anything. When not in VTEC, it just rides by itself. The two primary lifters stay on the valves at all times, BUT when VTEC kicks in pins lock the primary rockers and connect them to the VTEC rocker. Then the VTEC lobe forces the two rockers to lift higher and open the valves more.
Remember when I talked about airflow? How you can't have too much or you disturb the balance of things? The same applies in cams. If you have too much air/fuel moving in at a low RPM, then you aren't gaining anything, you're losing it. So when you make VTEC engage (using a VAFC or standalone) too early, you are trying to outflow the flow. There basically isn't enough air movement to handle what you're trying to do. This is a problem the old V8 guys have to deal with. If you've ever heard a V8 that idled like hell, with a nasty lope to it, that's because he had a higher lift, longer duration cam in there. It was flowing too much for low end and that causes it to idle poorly. But it sounds phat as hell. They have poor low end, but gain much more up top, where they race. Anyway, I digress....

</TD></TR></TABLE>

https://honda-tech.com/zerothread?id=180883 &lt;----this should keep you busy for awhile.

Then when your done with that, see this thread.

https://honda-tech.com/zerothread?id=435954

 

Thanks, i think i understand more how it works now.

 

good for smoothing out A/F curves, bad for "lowering" your vtec.

 

My a/f ratio is 12 or under through all RPM's. Does that need adjusting or does that sound about right?