apexi vafc vtec problem

[5thgen_prel]

i dont know whats wrong with the car or vafc but when i change the vtec cont to 4500rpm to 4300 vtec kicks in at 7200 ? pretty wierd huh do you guys know whats wrong?

[DriftKnightX]

was the apexi professionally wired up? if not check your wiring first!

[curtis265]

fcuked up installation i suspect

[HondaTurboVtec]

i dont know whats wrong with the car or vafc but when i change the vtec cont to 4500rpm to 4300 vtec kicks in at 7200 ? pretty wierd huh do you guys know whats wrong?

Ask a tuner or performance shop what the problem is with what is happening, I reckon once vtec has been changed from the original spot must be tuned according to it.

[GU357]

which car is this vafc in? Specs?

check your wiring, try disconnecting it and see where the original crossover is. and bring it up to 7200rpm and see if its making the same noise, maybe u just cant hear the cross over.
or the ECU does not deem it worthy to activate vtec yet because of oil pressure or Throttle position. all because u screwed with the wiring.

[migoreng]

You're driving a 5th gen prelude like mine I assume?

How can vtec kick in at 7200rpm?

Redline on the tacho is 7400rpm but the actual ECU rpm is about 7000rpm.


my lude is tuned and I can tell you the vtec crossover is not very noticable when set to <4500rpm.. If you listen carefully you'll hear a slight change in engine noise as more air enters the engine...Once you reach the normal VTEC rpm of about 5200rpm on the tacho, you'll feel a slight jolt due to the intake manifold dual runners opening up.

So that's how a a factory lude gets that VTEC kick/jolt....high cam+ intake runners opening = sudden surge of power.

Anyways you'll need a dyno tune to smooth out the power curve...

[HondaTurboVtec]

You're driving a 5th gen prelude like mine I assume?

How can vtec kick in at 7200rpm?

Redline on the tacho is 7400rpm but the actual ECU rpm is about 7000rpm.


my lude is tuned and I can tell you the vtec crossover is not very noticable when set to <4500rpm.. If you listen carefully you'll hear a slight change in engine noise as more air enters the engine...Once you reach the normal VTEC rpm of about 5200rpm on the tacho, you'll feel a slight jolt due to the intake manifold dual runners opening up.

So that's how a a factory lude gets that VTEC kick/jolt....high cam+ intake runners opening = sudden surge of power.

Anyways you'll need a dyno tune to smooth out the power curve...

Exactly what I stated, get it tuned. Moving the vtec from the original spot without tune is the worse thing to do!

[GU357]

apparently this:

Ask a tuner or performance shop what the problem is with what is happening, I reckon once vtec has been changed from the original spot must be tuned according to it.

means all this:

You're driving a 5th gen prelude like mine I assume?

How can vtec kick in at 7200rpm?

Redline on the tacho is 7400rpm but the actual ECU rpm is about 7000rpm.


my lude is tuned and I can tell you the vtec crossover is not very noticable when set to <4500rpm.. If you listen carefully you'll hear a slight change in engine noise as more air enters the engine...Once you reach the normal VTEC rpm of about 5200rpm on the tacho, you'll feel a slight jolt due to the intake manifold dual runners opening up.

So that's how a a factory lude gets that VTEC kick/jolt....high cam+ intake runners opening = sudden surge of power.

Anyways you'll need a dyno tune to smooth out the power curve...

according to this:

Exactly what I stated, get it tuned. Moving the vtec from the original spot without tune is the worse thing to do!

[EG8 CIVIC]

its a ek4

[GU357]

pull the vafc off, problem solved

[V73C]

^ literally, what this guy said. Not even shitting you