civicnation

On a stock b16a2 motor with stock header, aftermarket short ram intake, itr header back exhaust, is there any benefit in lowering the vtec crossover from 5500 to lets say 5000rpms?

if so, what is the benefit and why?

if not, why?

92extremehatch

u can hear vtec sooner and at a lower rpm and show off lol

civicnation

i have no interest in showing off, i just wanted to know if it would help me at all to lower it

zeeman

iTrader: (1)

meh, its debatable. I would say leave it where it is. I've messed around with the vtec crossover with both stock b16 cams and my aftermarket stage2's and i find the crossover is its smoothest (which is what you want) at 5500rpms.

civicnation

thanks zeeman. i've just been thinking about it for a while and couldnt get a good reason as to why it would help or why it would be bad.

i'd actually prefer to leave it where it is if it's the smoothest at 5500

zeeman

iTrader: (1)

when i first had the b16 swap i was using a generic mugen chipped p28 that had vtec set at 4800rpm. Which i found to be way too low. When vtec kicked in it was slower than while on the non vtec lobes and took a second or two to start pickin up. So i set it at 5200rpm (with a vafc2 i used to have) and it felt quite a bit better. Then i ditched the vafc for crome and set it to 5500 and tuned the maps and i'd have to say 5500 is the best point IMO for b16s with stock cams.
Honda spends big bucks on tuning their engines, there is a reason why they set it where they did.

imported_italstallion

yep i completely agree with that if it was more beneficial to be at 5000 honda would have done it from the beginning.

ElitE Perf.

the reason its honda sets it where it is for economy alot of ppl drive around all day just below 5 grand when you drive abit harder over 5 grand you reach vtec when and where it is needed...

lowering vtec slightly does have its advatages but only when car has work and tuning done for it to really make a difference....

civicnation

thanks guys, i really appreciate the input

zeeman

iTrader: (1)

Not from what i've seen.
This is only remotely true on b20vtecs. They can get away with a lower vtec xover b/c of their displacement. Or unless the cams you are using have vtec lobes that were designed to operate well in lower rpms. But usually if the cam has a different than stock vtec xover its higher not lower. Meaning the non vtec lobe profile was designed to operate at higher than stock RPMs.
Think about it, from 4500-5500 is when the non vtec lobes are making as much power as they will be making. Why would u want to switch to the vtec lobes, which make their max power at 7000-8000rpms, before the nonvtec lobes are done making their max power?
Like i said before honda put it where they did for a reason....b/c thats where they've determined it works best. And by they i mean a group of incredibly smart japanese engineers with almost unlimited resources.