I recently swapped my D16y8 SOHC 2-stage VTEC in a '97 Civic EX Coupe for a 3-Stage JDM D15B VTEC because my old engine gave out on me. The only thing non-standard was the 104-tooth p2f timing belt. The timing marks lined up fine so I figured there wasn't a problem although everthing I've read online says that a 103-tooth belt is required. Acceleration/Power is great maybe better than my old engine until I reach 3.5 to 4,000 rpm. From that point until VTEC kicks in(about 5.5k rpm) acceleration/power sucks! Everything other than that seems great... that is the essence of my problem, though. This is almost exactly the reverse of the performance of my old engine. I have a hard time believing that the timing belt is the problem because all the timing marks line up perfecly but i am open to suggestions. We also decided not to use the dual-silenoid vtec instead using my old vtec silenoid since the wiring wasn't ready for dual. This was a straight swap. No other modifications. What am I leaving out?. Does the ECU need to be chipped? Are there other factors I'm leaving out? I need some help! NOOOOOOOB.

 

id have to say its something with your vtec. maybe you need to run the D15b solenoids rather than the d16y8? just to throw that out there

 

hello, well first of all. i have the same motor but opposite problem. i no power at lower rpm before vtec.. but when vtec hits.. its very good power.. and i know why this is happening.

well, for you situation. you should use the dual selenoid because one activites vtec at low rpm and another at high rpm. the only thing why your is not working is because. if you have the p2p ecu, the original ex ecu.. it will not activite the one vtec.. so you will either have one vtec either at low or high rpm...

The choices you have know is.. find the jdm 3 stage vtec and use the dual selenoid.. which is hard to find..

, you can also hook up the dual selenoid and connect the high rpm vtec to the ecu and buy a vtec controller to activiate the low rpm vtec to kick in.

or lastly.. you can use the replace the head to the y8 which is only 2 stage


and for me.. i am going to swap head to a y8 head.. havent done it yet but will soon.. i'll let you know how it goes ..

 

if you have questions comments email me because i dont really go on this ..

richardb0343@yahoo.com

 

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