Originally posted by GReddyboy
Great explantion guys thanks! I also have another question regarding cams. Say putting some toda specbs on a b18c motor. Why couldn't they just stick with a stock primary cam lobe instead of changing it to more aggressive? I mean isn't the stock lobe more better and more power for the low end, whats the point to alter the primary lobes, i thought vtec motors are designed to keep the low end power and have a stock idle? Is there any cams out there that has a stock primary lobes but has a very aggressive vtec lobe? What I want is a type r stock primary lobe with something like a toda spec b vtec lobe. Thanks again
I'm just 'trying' to answer your question as i'm not very long in this :P the mod here will sure give you a better answer and i will too learn from it .
If im not wrong its because the stock Vtec cam doesn't make power till above 10K RPM but those after market cam does hence they gotto change the profile to make power for higher RPM even for primary cam lobes which made the idle at higher RPM too. for example Stock cam switches to Vtec at about 4500 - 5500 RPM where those after market cams 'may' switch into Vtec only at 5500 - 7000 RPM which totally move the whole usable powerband higher.
Sorry if i were wrong :P