What?With spoon venturi throttle body and a good intake, mpg is not affected, however, with the high cam shaft kit, mpg will be lower over long distance.
the best thing to do would be to change only the programmatopn of ecu to have more rpm and more fuel over 4000 rpm, then long distance mpg would be the same, and when you need power you will have more, only WHEN needed. The included ECU does that, but with one closed intake valve this is not the same program.
This is NOT a vtec killer, this is a valve opener, since vtec is still there, vtec modifies still the TIMING at high rpm.
This mod only insure that you have 16 valve all the time. The two cams have a shifted angle, so vtec is still there. Maybe the shape of the high rpm cam is a little more agressive, but i don't know.
the one included with this kit is tuned for the spoon cam. they have not released another ECU that can tune for a raised limiter and for fuel. One of the piggybacks may work (like AEM) or you will have to wait for Hondata (or wait for more info on HKS f-con)Hum Good to know! so you think they have made 2 Ecu one for the cam and one just to raide RPM?
If this is the case, going into VTEC means switching to the low cam for fuel efficiency while being out of VTEC means the motor runs on High cam for power. If the CR-Z is like this then the VTEC switchover changes the motor profile from 16valve to 12 valves. The Spoon cam kit would replace the intake cam and never allow the motor to jump down to efficiency mode at 12 valves. By doing this the engine would stay in performance mode with the full 16 valves open and there would be no VTEC switchover, hence VTEC killer.The new DBW (Drive By Wire) system on the R18A now constitutes a major and crucial part of the R18A's SOHC i-VTEC mechanism. Firstly, it provides the high-precision control over the throttle valve required while the valve timing is being changed over, ensuring smooth driving performance that leaves the driver unaware of any torque fluctuations. Secondly, and more importantly, during the economy mode there is the unusual, and conflicting situation where while the throttle pedal is at an almost completely closed position, the throttle butterfly in the throttle body is in an almost completely opened position, the exact opposite ! However, this relationship only applies when the engine is running in economy mode, when VTEC has activated the fuel economy cam lobes. In normal running, the normal relationship between throttle pedal position and throttle butterfly opening remains, i.e. light throttle means small throttle butterfly opening, etc. Thus the SOHC i-VTEC mechanism used in the R18A is only possible with a DBW system.
So the new SOHC i-VTEC implementation is an entirely new implementation, quite unlike those already in use. Under normal driving conditions, the R18A runs on its normal set of cam-lobes which in a completely reversed role, Honda calls the 'hot-cams'. So VTEC-off on the R18A means it can be considered to be running high cams. When the right conditions are acheived for fuel economy, VTEC engages the 2nd set, the 'low' or 'economy' cams. Thus VTEC-on on the R18A means it is running low cams. More importantly is VTEC engages the low-cams only if the right conditions for fuel economy are acheived. If they are never acheived, like when we are driving aggressively for the whole trip for e.g., VTEC will never open on the R18A. Thus it is a completely different idea from the VTEC implementations of old where VTEC will always open after a certain rpm, irregardless of the driving conditions. This is also the reason why Honda feels it is justified to call this new implementation an i-VTEC implementation, 'i' of course meaning 'intelligent'. This is because the engine/ECU is 'smart' enough to know if conditions are right or not for VTEC to engage. This new mode of operating is clearly illustrated in the 3-dimensional torque-rpm-driving load chart on the left (supplied by Honda). Note the standard torque curve. This is the line right at the top of the chart and VTEC never activates across this torque curve. On the other hand, VTEC opens across a fairly wide range of driving conditions, in the shaded portion inside the torque curve. So if our throttle pedal position or other critical driving conditions are outside the shaded portion, the R18A will not engage VTEC at all