VTEC upgrade?

i just read in one of the UK bike rags that Honda improved the VTEC transition in a later model 6th gen (maybe the '06 model?). i've got the '03 ... esp. at around town commuting speeds, the 6700ish rpm transition to/from VTEC is very abrupt. The article makes it sound like it's barely noticable in later models. Does Honda have a way to upgrade the older 6th gens so the VTEC transition isn't so jumpy? Is this an issue of remapping fuel injection, etc?

kevin

'03 VFR (silver) in San Anselmo, CA

 

They lowered the rpm in which VTEC kicks in to get rid of the engine running out of breath before the second set of valves open up. I have a 2006 model and the transition is very noticable. But since I haven't rode a 2002-2005 I can't compare them. I did install a PC III USB and the transition is now much smoother.

 

what does the PCIII install involve? easy? difficult?

thx!

kevin

 

I'm certainly not the most technical person here and I thought the install was very easy. You pretty much just plug it in and route it under your seat. Try a search on Power Commanders here for more specific detail, it's been talked about recently in a couple threads. Good luck!

 

It took me about 40 minutes including the O2 eliminators. Was very easy, just takes a little time. I think it is the best bang for buck I have put on the bike. It took away all of the things I was irritated with.

 

I have the PC III on my 05 and it smoothed the transition out considerably. It is still abrupt when cold, but much smoother when warm. I have heard the same you did about the new VTEC threshold. It seems to me I read it was on the 07 model and the new threshold was at 6400 rpm.

 

Vtec threshhold

The engagement point for the VTEC has been altered so that it engages and disengages at different points so that the system does not "hunt" around the 7000rpm mark on a steady throttle. This is from the '06 model onwards.

 

So, is that an electronically controlled function? If so, does anyone know if an 05 can be retro-fitted to those specs and what the cost might be for that?

 

There's an article from a few months back on that. If I rember corectly you must use the '06 computer, which doesn't work in the '05 at all, for whatever reason.

I ahve the '06 and the PCIII cleared up ALL the problems (I've written about it a few times). I recently changed the map to one of the ones I downloaded from Powercommander.com and am getting way more power. 'Way more power' being measured by the seat-o-the-pants dyno. I'm glad the PCIII was the very first thing I invested in on this bike.

 

Does installing a powercommander necessitate redoing the exhaust? What happens to fuel economy when the PC is installed?

 

I'm running bone stock with the PC III and loving every minute of it. I went from 46 mpg to 43 mpg as far as I can tell.