<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRXizSLAMM’d &raquo;</TD></TR><TR><TD CLASS="quote"> iv never heard of anyone doing this, but it seems like it would be a good idea. if i took the rod that links all three lobes on the camshaft at 4000 rpms for the vtec, and somehow got it to stay there all the time, then i would have constant vtec running. it would be bad for gas mileage at low rpms, but with my dohc vtec, i dont usually go slow. any opinions....?</TD></TR></TABLE>

It's never been done before, youd be the first to do it!!!11

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRXizSLAMM’d &raquo;</TD></TR><TR><TD CLASS="quote"> all that the vtec does is allow your valves to open sooner and stay open longer, therfor giving your engine more oxygen. i dont see how you would lose power at low rpm just because you give it more air. granted, i would have worse gas mileage and a high idle, but over all, i think that it would give me more power off the line and at high rpm, if im wrong, please explain how...

i could go with differnt camshafts, but money is tight right now, so im trying to be cheap...</TD></TR></TABLE>

It's called turbulent mixing. Fuel not mixed with air will burn in your exhaust, not the cylinder, resulting in horrible emmisions, bad gas mileage, and reduced power.

Your engine is getting plenty of oxygen at low RPM on the small lobes. Imagine breathing through a straw. It's easy when breathing slow. However, if you breathe fast (like when running), you need a larger diameter straw to fill your lungs with each breath. VTEC does the same for your engine. It just ensures that there is enough turbulence to mix your fuel with the air.

You need to do some reading. Try Google.

 

First, when you get a VAFC tunned don't they usally end up raising vtec crossover more often then lowering? it gets more power that way I think.
Second, with vtec on all the time you would accomplish nothing but, constantly bogging out.

 

well i actually did it yesterday and i was losing a little power, so i upped the fuel pressure and it worked perfectly i now have(for stock parts)the most air/fuel mixture possible and it really is movin a lot faster than before. ill no doubtably wear out my parts faster, but my goal was and still is to go faster, and it worked. thanx for all of your posts tho.....anyone with vtec and a fuel presusre regulator should look into trying it.

 

no thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRXizSLAMM’d &raquo;</TD></TR><TR><TD CLASS="quote"> well i actually did it yesterday and i was losing a little power, so i upped the fuel pressure and it worked perfectly i now have(for stock parts)the most air/fuel mixture possible and it really is movin a lot faster than before. ill no doubtably wear out my parts faster, but my goal was and still is to go faster, and it worked. thanx for all of your posts tho.....anyone with vtec and a fuel presusre regulator should look into trying it.</TD></TR></TABLE>

How did you measure this purported increased performance? My guess is that you felt a kick around the 4,000 RPM mark. The point is don't tinker with what you do not understand.

 

I'll bet oil pressure in the head in the lower rpms is not ideal for VTEC activation. I can assure you that low end power is lost by what you are trying to do. Rethink pls.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">I'll bet oil pressure in the head in the lower rpms is not ideal for VTEC activation. I can assure you that low end power is lost by what you are trying to do. Rethink pls.</TD></TR></TABLE>

Yes I agree J. Davis, Correct me if I am wrong, but the idea is to use a smaller opening (valve lift and duration) during low rpm operation to use the velocity and momentum of the air to help fill the cylinder. When you use high lift and duration during low rpm you end up loosing this effect because the piston creates less vacume on its intake stroke. Also you loose the effect of the different size of the primary and secondary lobes to swirl the air.

The whole point of vtec is to provide efficiency and tourqe at the bottom end while making great power at the top end. When you adjusted the fuel pressure regulator you were probably making the mixture more rich because you are not pulling in as much air as before. If possible you should get some dyno results from it. It would be a good experiment to see what the difference really is. Please keep us posted on it but I can safely say you are loosing bottom end power.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Imagine breathing through a straw. It's easy when breathing slow. However, if you breathe fast (like when running), you need a larger diameter straw to fill your lungs with each breath. VTEC does the same for your engine. It just ensures that there is enough turbulence to mix your fuel with the air.
</TD></TR></TABLE>
very good example.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">I'll bet oil pressure in the head in the lower rpms is not ideal for VTEC activation. I can assure you that low end power is lost by what you are trying to do. Rethink pls.</TD></TR></TABLE>

This is another good point. I'm not sure what would happen once you hit higher RPM, where the oil pressure would be adequate, and then returned to lower RPM. Would all of the VTEC pins disengage, or just some of the pins? This may lead to shearing of the pins and metal chunks in your motor.

 

none of the pins would retract because i put a small weld on them. im not sure what the dyno result will be, but i drove my car the way it was before for about 2 years, and i can say that off the line, it is faster. i have encountered some small problems such as idling, but with a little tuning i think i could make it work near flawlessly. but i did just get a raise at work, so when i have the money, i am goin to invest in new cams, but for the time being, its really not so bad....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
The whole point of vtec is to provide efficiency and tourqe at the bottom end while making great power at the top end.
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That might be a goal of variable valve timing, but vtec on B series engines really is only good for idle and emissions.

Looks at some non-vtec dynos vs vtec dynos, you will see what I mean.