What would cause a loss in power when VTEC kicks in with boost at around 8 psi? VTEC does engage cuz we can hear it but there is no real gain in power and from the dyno graph we have it really starts to drop and af/s are everywhere! We have come up with some reasons but I'd like to see what others might suggest.
1. Cam timing
2. something wrong with the cams, valves, valve springs or retainers
3. ignition timing (although it is pretty much stock, manually retarded it a bit)
4. oil
5. Turbine wheel could be too small. I used to have a .48 housing and wheel (stage 3 I think) and I replaced the housing with a .63 housing but kept the same wheel. The .48 housing seemed to choke at higher revs and with vtec, so I'm wondering if it's more the wheel?

I've pretty much ruled out fuel cuz we're running around 11.5 or so, so it's pretty rich as it is but still, we're really wondering why VTEC is not bringing in the numbers like so many of you out there.


Modified by ludelvr at 10:26 PM 7/23/2003

 

hows the oil pressure in the engine?

 

well, I'm using the oil port on the side of the block by the vtec solenoid ( I think mostly everyone with a h22a uses that port) and I have a rubber line going to the turbo and I'm using an autometer gauge (those unreliable and inaccurate 0-200 psi ones) and it's reading around 50 at normal operating speeds all the way to full throttle boost. Shouldn't these numbers be higher? as well, would the fact that I'm using a rubber line account for the lower pressure? Also, does type of oil, whether synthetic or not, make that much of a big deal...I'm talking like 50whp worth?

 

for some reaon i think the oil pressure should be at about 80psi @ WOT under a heavy load.

 

Could the fact that I'm using a rubber line instead of a braided one affect this? Also, It's tapped in line from the on the side of the block going to the turbo. It's a 1/8th barbed fitting so there's not that much pressure to begin with, but I'm not entirely sure.

 

oil pressure should be around 75psi under high load/ freeway speeds and like 12-15psi idle.


sorry im not much help

 

ttt

 

Oil pressure is RPM dependent. Throttle percentage plays no role really. 50psi is pretty low that high up. From about 0-2K is should be around 15-20psi. From there to about 5K rpm or so you'll see around 45-50 psi and after that should be steady 75-80psi. These are generalized numbers. Individual results will very slightly. Def be more then 50psi up top.

 

ok is there a loss in power or just no real power gain? if your motor is tuned right the dyno graph should have a relatively straight line. a poorly tuned engine will show a great performance increase once vtec kicks in... but thats bad b/c you're losing all that power before vtec kicks in. get what im saying?