Surely fuel economy will be worse with VTEC engaged at a lower rpm point, more fuel and air going into the engine? Or am I talking rubbish?

 

you can't get something for nothing. If you lower the vtec you get more power and more fuel consumption. If you wnt to talk power don't talk about mpg, it's a contradiction. I am about to work with AEM to see if it will give similar results to the Hondata RSX K-pro (which is the mutts nuts) but costs over

 

I was told (by a Honda fan boy) the DC2 had much more of a kick, but it was down to a mapping problem and could be "fixed" if that's the right term. Maybe they're doing it deliberately now?

 

It's not a contradiction at all. More power can be had by making the car more efficient at a given RPM. Not something for nothing, get more for what you spend

Hence, you can have more power and get more mpg too.

 

droping the VTEC change over does not guarantee more power lower down, if the engine is not reving fast enough you can bog down on big cams, its OK to move it by 500 rpm and maybe 1000 but you will loose something. I have an old alfa with high lift long duration cams and you have to keep it on the boil to make it shift anything below 3k and forget it. The bigger cams used after 6k have more overlap to make use of scaveging effect created by the exhaust manifold, with lower engine revs the exhaust gas has not enough inertia and you actualy loose power due to exhaust gas being left in the combustion chamber or worse exhaust gas being pushed back into the intake manifold.

 

Get a programmable ECU then?

I had a VAFC on my car for a while. Was reasonable. with a de-cat and single exit exhaust I managed to move the vtec point a bit lower (4.5k) and I gained about 6bhp peak (a lot more over the mid range).

But overall it was a bit pointless throwing money at NA.

 

[QUOTE=HORSEPOWER,Apr 8 2008, 10:03 PM] I am about to work with AEM to see if it will give similar results to the Hondata RSX K-pro (which is the mutts nuts) but costs over

 

Ok everyone,

Just about followed this hugely technical thread. Seems to me that it is possible to lower the Vtec point but there is no real benefit to doing such a thing.
What I was really after was some low down punch, owing to the lack of torque. I figured lowering the point at which the Vtec became available would do the trick...shows what I know.

Anyone got any better ideas as to how to unleash some low range grunt?

Matt.

 

Change final drive. I keep saying it becacuse it's true

 

Lowering your final drive will make the car quicker. But it'll kill the top end.

Personally I like having a 180mph top end, as it means I'm at 4500rpm at motorway speeds.

It doesn't give you "low down" power .. it just drops your top mph in each gear. So instead of doing 40 in first at redline (and Vtec power coming in at 26mph) you end up only doing 36 a redline, and Vtec coming in at 23mph. Also means it's harder to keep on the boil, as you have a shorter power band when relative to speed.

FI is the only way to get proper benifits. Add a turbo, supercharger .. or even add Nitrous.

Turbo's suffer from lag, the centrifugal SC's only give minimal benifits lower down the rev range. Nitro needs filling up, and I'm personally not a fan.

Either that, or sell it and buy something that is actually quick to begin with.