Guys, I recently put a fully built race motor with a JG Race Head in my 95 civic ex, eventually going turbo. The problem is that when I hit 5k RPM the Vtec feels very weak, I dont get the familar "lumpy" sound, the sound just gets louder at the Vtec crossover point, I had the same problem when I had the stock GSR intake, now I have a Skunk2 intake, there is no change. However, in spite of this the car seems responsive and fast but it still seems that something is still missing. I think that lumpy sound comes from the higher cam profile, but I am noyt getting it. I changed the Vtec solenoid but no difference. Someone suggested that the stock cams might not be compatible with that aggressive port job on the JG head, any comments will be greatly appreciated, thanx.
I have 10:1 JE Pistons, Crower Rods, Polished Crank. The head has SS Oversized valves, with titamium retainers and double springs.

Colin


[Modified by Liltrix, 11:43 PM 10/26/2001]

 

No help available?

 

Sounds like it needs tuning up top to get more fuel with that much more air and compression. Stick a set of 310cc injectors in it.

 

Thanx Jared, anyone else? I will appreciate it.

 

Imagine that!! A board with several thousand people and only Jared saw it fit to offer any type of assistance. This speaks volumes of the kind of "friends" we have on this board. I thought we are here to help each other out, at least just to know that we have buddies on the net sharing the same problems, concerns and the same hobby.

 

have you got an air/fuel ratio meter

 

Not sure if this will help, but I had problems like this on my Integra, with the Toda and JUN cams. I got that bog when VTEC first hits, and it didn't feel healthy. Using a VTEC controller and moving VTEC up to kick in at a higher RPM helped it. When the ECU kicks VTEC on, the ECU changes fuel maps drastically. With your ported head, you may be getting too much flow when VTEC switches, so the ECU doesn't know what to do. That may be why it feels weird. If you have a VTEC AFC or something, try to either move the VTEC up (to about 5500 to 6K rpms), or try playing with the fuel maps.