We're all looking for that little bit extra for our cars, especially those of us that race.
A tweak here and there that gains us a second or two is fantastic. In my career I've found not to limit myself to only looking at/for tricks for cars. Many times I can find something totally unrelated to a car that can be used to pick up that little bit.

Anywho, stumbled on a bit from a motorcycle rider/builder. He has a wild concept, showing he can outperform a bigger horsepower bike, with a less horsepower one. A bit technical in how it works, but in layman's terms it's Velocity vs Flow, in the ports of the cylinder head. His ports are smaller, even smaller then stock. His design speeds up the flow of intake air, and increases the exhaust flow.

Something we've all been taught is wrong. To go faster/ bigger power you need bigger ports. Yet here is this guy with track and dyno proof showing the exact opposite.

Since we now have a spare engine... It's going to get a rebuild down the road, and I may just give this a whirl on the ports.

If you have a long bit of free time, check out this site and give me your thoughts.

http://www.mototuneusa.com/thanx.htm

 

We're pretty familiar with the concept. It works, to a point. That's why I have stock-sized IC piping, TB, exh mani, turbine housing, etc.

 

that site and its information is very old. the concept is valid to a point.
i think the take away should be more along the lines of proper sizing of ports rather than making them smaller. motorcycles are very small displacement and the ports on the heads are pretty big. in that guys particular racing style, having a little more torque is beneficial.
look at the 1g dsm heads compared to 2g and evo heads. mitsu made the ports smaller.

 

the concept has to do with the width of the tq band / powerband.. in other words, use a properly sized turbo with modern aerodinamics and ball bearing core and do not go OTT on the cam selection.. Staying with stock sized valves works too..

 

It's all about air velocity, which is how you make power sooner. Small valves, small TB, small ports, all add to lower-RPM velocity, but hold it back top-end. MIVEC is a back-door way around this, you can crank up the velocity by messing with cam timing. Playing with the exhaust can spool the turbo sooner, playing with the intake can give more power everywhere throughout the RPM range. Same with variable-length intake manifold runners. Longer runners = more velocity = more low-end grunt. Switch to shorter runners at higher RPM to lessen restriction, more power. With modern turbochargers and cam trickery, having a 4500 RPM powerband isn't out of the question at all.

 

In my opinion, Honda nailed it with the B18C engine in the GSR Integra: longer intake runners and smaller cam lobes for low RPM and then shorter runners/larger cams for high RPM. ****ing genius. Best of both worlds and made for some really fun engine sounds.
Technology is awesome.

 

hell, you can do that on stock block e9 with s2 cams and hks 7460..