Can Vtec Activate too late?

[Accordturbo94]

Hey everyone i just had a quick question! I just resolved a problem i had with my cars vtec.. Ive never ran this car w/o my vtec controler on. I have always setup the h22 to enage at 5000. the ecu i have in my car i bought off ebay and it was jun chipped i believe like a 5700 or 5900 vtec engagement and what not. Well tonight after figuring out why i was getting a vtec oil pressure code. I took it out for a test drive.. w/o the vafc on! It just didnt seem to roar like it does at 5000 or pull anything like it.... Is this normal and indeed that you can have vtec engage to late? im hoping that there is not something else wrong.

 

[xj0hnx]

Honda knows when the vtec should engage in their motors for best power and effectivness, you shouldn't alter engagment without getting it on a dyno and confirming power gains.

 

[Accordturbo94]

well that doesnt really help me now!

 

[pills_PMD]

he is saying that the low cam profile doesn't make power after a certain rpm, but the only way to find out what that is would be to take the car to a dyno and try different engagement points.

 

[Accordturbo94]

it runs good and everything.. and revs strong till vtec.. and when it kicks in at the 5900 or what ever exactly it is.. it breaks off and doesnt rev as fast! Before when vtec enaged at 5000 it would rev strong and as soon as it hit vtec the tires were spining and revs shot right up to 8000! Now it seems to struggle to get there.

 

[Jim Truett]

Originally posted by Accordturbo94@Dec 31 2003, 07:46 PM
it runs good and everything.. and revs strong till vtec.. and when it kicks in at the 5900 or what ever exactly it is.. it breaks off and doesnt rev as fast! Before when vtec enaged at 5000 it would rev strong and as soon as it hit vtec the tires were spining and revs shot right up to 8000! Now it seems to struggle to get there.

I seriously doubt the ECU alone is able to supply enough fuel for the H22 at high rpm, and that is why you are seeing a power loss. Especially if it is a bootleg eBay performance chip. I bet it is programmed with P30 (B16) code.