well, here we go
Vtec is basically the engine switching to another lobe made to handle the high RPM's thats y the change in sound, its switching from the low RPM lobe to the high RPM lobe. umm, 90% of the vtec's u see around canada and US are SOHC Vtec's with wont really be that amazing Vtec push u will expect. they are made more for being fuel effiencient than raw power, not to say u cant notice it cause u can, just a DOHC vtec is alot more aggresive. umm, i do not know if the EX is vtec, check out reference section to check, but it will NOT be fast out of the box. a SOHC vtec civic Si coupe, will run arond 16.00 stock, which is very slow in racing terms. most of the people u hear about that have amazing vtec kicks, either use a b16 or b18c1, they are DOHC and produce amazing power ( 100hp/L)
B16 = 160hp
b18c1 = 180 hp
d16z6(sohc vtec)=125hp
the problem with DOHC vtec's is the only cars they come in are,
Integra GSR = B18c1
Integra Type R= b18c5
and Civic Si(USA) Civic SiR(CAnada) = b16
all of these cars are coupes therefore are heavier than a hatchback, so what we do here is swap these fast engines meant for heavier cars, into smaller lighter cars to get real fast little hondas. engine choice depends on budget as well as what u want to do with the car. so if u wanna know the right engine to pick make another thread to do with that.