Vtec gets more hp because it "switches" camshafts at higher rpms. (sorta not really, http://youtube.com/watch?v=AcT_ZyY3F0k theres an explanation for visual learners, that link made me more confused^)
heres another explaination: http://www.youtube.com/watch?v=q24D0xv49d4

Vtec is bad for boosting. To tell you the truth, im not really sure why. Its just what i hear. Maybe one of the more experienced members will chime in and say why.

 

vtec isnt really bad for boosting if you built the motor. Alot of pressure it put on the motor when VTEC and turbo are both used at high RPM. without proper biulding you can damage your motor. PLus alot of honda racing motors like the k20 and b18. use very high compression ratio. One of the reasons the new RDX turbocharged when it reaches vtec rpm range actalluy lowers the boost to the motor stays reailbe and strong. But at low rpm it uses more.

 

How does VTEC put pressure on the engine? It opens the valves more and longer which would reduce strain. I could forsee a problem if the turbo is allowed to engage before the VTEC though.

 

On a turbo setup you want to have the overlap duration of the open intake and exhaust valves reduced to a stock level, even with tuned aftermarket cams, and keep it at the same duration in the entire RPM range. Vtec works great when you have no turbo cause the longer overlap duration allows some of the incoming fresh help push the exhaust gases out, leaving a cleaner atmosphere to burn in the cylinder. Theback pressure produced by having a turbo's exhaust turbine in the exhaust flow can actually cause some of the exhaust gasses to flow back into the cylinder if the exhaust is open too long and the duration of overlap is too long. This is why non Vtec or vtec eliminating cams and rollers are often found in real built turbo systems

 

Looks like Shadow just pwned this one.

 

F22 and F23 are both Iron sleeved, But F23 rods are thin like a spaghetti... Stay with F22 blockand since you want to swap a head, get 1 from H23a1 DOHC prelude, some ajustable cam gears and... You'll be set foraround 160 hp baseline. With all the ajustability you wish to have on a turbo project. I'm personnaly rolling a 150 000 miles F22a4 with DOHC head in my civic... Pushing down nearly 250whp with 14psi (I know, It wont last long but I'm currentlybuilding another F22a4 with forgedrods&pistons) Already 8000 miles on the setup, Still running verystrong !!!

 

Why does the ECU do all the oil checks and coolant checks to make sure everything is good before it activates? It must cause more starin on the engine and the ecu wants to make sure everything is ready before it delivers that power.

 

I don't like speculation. Explain the checks that you are talking about. As far as I know, oil pressure and coolant temperature are monitored continuously on all OBD2 cars.

 

VTEC does not put strain or pressure on the engine. If it did, it wouldn't be there in the first place. However, VTEC will not engage unless the conditions are right, engine speed, oil pressure, etc.

 

so, my car is turbo and i left the VTEC on... should i unplugg the VTEC?