I remember the days when the non-VTEC engine was king and Honda nerds were too scared to touch an engine with VTEC stamped on it. The B18A had every type of cam package from mild to wild, while the support from the aftermarket left the VTEC valvetrain untouched. A few years down the road the situation was reversed and everybody was sporting the VTEC badge. To this day, cam manufacturers are finding new profiles to squeeze even more horsepower out of the B series engine. When VTEC was first introduced, Honda fans had no idea the advantages of having a low to high cam profile. And from the cam manufactures stand point, they had to figure out two different profiles for the exhaust cam and another two for the intake side. This involves getting the cams to transition smoothly from high to low as well as to handle high rpm. Once efficient grinds were designed it was the time to see how well adjustable cam sprockets would add to the mix.
Adjustable cam sprockets became the key to unlocking power out of any camshaft combination. By simply changing the valves' open and close time on a given camshaft, more power could be unveiled, making the adjustable sprocket a valuable commodity. Cams with adjustable cam sprockets became an absolute must on B series engines. In the long run manufacturers were able to discover what does and does not work; whether their cams were at zero or if adjustable sprockets were used. This isn't to say the B Series cams are a done deal, but with the many different combinations available, the hard part is just finding the right one. With this history lesson done, there's now a whole new can of worms that's been opened when dealing with the new K series engine housed in the new Civic and RSX.
Most cam manufactures have VTEC grinds conquered, but now the aftermarket has to deal with VTC (Valve Timing Control) on the new K Series engine. With a combination of VTEC and VTC, cam profiles and cam sprocket adjustments have been taken to the next level of horsepower. Honda's VTC eliminates the use of an adjustable cam sprocket with an electronic adjustable intake sprocket. One of the major differences from this sprocket to an aftermarket adjustable unit is the K Series ECU can give a plus or minus of 50-degrees of cam timing.
First off, let's start by saying 50 degrees is a shitload of cam timing, in either direction! Most B Series adjustable cam sprockets only allow a plus or minus of 10 degrees. How Honda was able to get away with 50 degrees is rocket science, but if you do the math, this is 100-percent possible. It doesn't mean that you should start notching away at your B Series sprockets to get more out of them; this just means the K Series valvetrain was designed after having this type of tolerance. To start with, the three main reasons this technology was added to the new line of engines was to improve gas mileage, exhaust emissions and performance. At idle, the sprocket is adjusted to the retard position to lower emissions. As the rpm increases, the intake cam is moved to advance the valve timing event, increasing horsepower as well as allowing a complete combustion of air and fuel. One would think that aftermarket cam manufactures wouldn't touch this with a ten-foot pole, but one manufacturer decided to try and tackle Honda's new technology.
TODA "Engine Kit" answered the solution to making more power out of the K Series. TODA Racing has extensive engine development experience with the K20A, starting with development of full race versions for the Japanese N1 and N+ racing series. There are several Japanese N1/+ race teams using TODA K20A engines (example: 5ZIGEN DC5). Now with all the various tuning, involved with the K20 engine's camshafts, TODA had to add a few other necessary components to complete the package: TODA uprated valve springs and ECU ROM tune. The valve springs were added because of the raised rev-limit and higher cam lift. As far as the ECU, raising the rev limiter was only one part of the solution to making more power.