Might sound dumb but…
I heard that a VTEC engine isn’t that good to boost?
Is this true??
That’s because of their high compression ratio which starts around 10plus:1 There have been instances where VTEC engines with stock compression have been boosted before, but the boost level is pretty low…around 5-7psi. If you want to boost a VTEC motor reliably, you gotta lower the compression ratio. People here seem to agree that a 9.0:1 ratio is a good number.
Regards,
Oz
The issue with compression ratio is one thing, but with good tuning a higher compression 10:1 or 10:2 engine is great for lower end responsiveness. A lower compression engine typically is sluggish at low points in the RPM band. Granted you will probably not want to go above 12 psi on a c/r of 10:1 or higher, but it will definately provide great streetable power.
A boosted VTEC just needs to be tuned. More aggresive cams with larger VTEC lobes cause both intake and exhaust valves to be open which allows boost to blow right through the engine, good for all motor bad for FI. Again, keeping duration to a minimum will make for outstanding gains.
thanks for the help!