B18C2 Crossover question

[immigymp]

not sure on this but is but do the vtec's cams switch simultaneouslty?

[vinnY]

^yes on b series
the thing with b18c2's is that they have dual butterflies so it sounds like there's two crossovers

afaik a mates dc2 just changes tone at 4400 then gets louder after 6000
i personally wouldn't worry about it, it's just sound

[fabian0]

Hei guise

Before we get started, the car is

- 94 B18C2 motor (vti-r DC2)
- serviced last week with HAMP filter, 5-40 semi syn oil, new plugs, engine flush also carried out.
- New VTEC solenoid gasket
- solenoid itself taken apart and cleaned properly.
- Before a VTEC test is carried out, the car is warmed up for around 20 minutes.

Now, my question is.

Does the second butterfly (6,000 RPM) and the VTEC crossover (4,800 RPM) work together?

I cannot hear my VTEC engaging at around 4,800 RPM, BUT i can hear something occuring at 6,000.

I presume what occurs at 6,000 is the secondary butterfly opening.

I just want to know if they work together, because if they do, my 6,000 RPM secondary buttery is working THUS my VTEC crossover will be to.

I don't think they work together, though.

any thoughts?

you got it the other way round buddy.

Secondary butterfly in the IM opens at around 5000rpm and VTEC kicks in at 6000rpm.
That is if your car is stock and has not been tuned. For example, my dc2 has been tuned with VAFC2, and my VTEC kicks in at 5000rpm, right after secondary butterfly opens.

In a nutshell, if you hear a louder sound @ 6000rpm, your vtec is probably working just fine.

[SHOGUNOVDDRK]

Turn your bloody Air conditioning off!!!!

[POPSIKAL]

I hear mine change at 4500rpm then can feel it really pulling at 6000rpm, also is louder after 6000rpm

[CRXer]

B18C2 vtec is 4400rpm at WOT....... full stop end of story.

[OMG.JAI xD]

you got it the other way round buddy.

Secondary butterfly in the IM opens at around 5000rpm and VTEC kicks in at 6000rpm.
That is if your car is stock and has not been tuned. For example, my dc2 has been tuned with VAFC2, and my VTEC kicks in at 5000rpm, right after secondary butterfly opens.

In a nutshell, if you hear a louder sound @ 6000rpm, your vtec is probably working just fine.

Lol.
Vtec engages at 4,500 rpm (or somewhere near there. 4400 4450, what ever, it differs by oil pressure. Changing oil viscosity change move it up and down a few rpms).
Secondary intake butterflies open at 6000rpm.
Vtec does not engage at 6000rpm. And you still will hear the note crossover with or without vtec working (if you only have an intake) But it will be sluggish.

Trust me. Having a dc2 with a straight pipe you can DEFINATELY tell the exhaust crossover note, and its at the 4500rpm mark. And exhaust crossover note cannot be heard with secondary intake butterflies. That only effects intake.


With stock air filter, and just the cover taken off it. You gotta have bats ears to hear the crossover at 4500rpm.
The revs are too low for any real notable change in sound. Even with cai or sri.


At the end of the day. Vtec at 4500RPM (differs by a few rpms with oil pressure, temp, viscosity, and all that mumbo jumbo)
Secondary butterflies are opened at 6000rpm.

[An41]

Lol.
Vtec engages at 4,500 rpm (or somewhere near there. 4400 4450, what ever, it differs by oil pressure. Changing oil viscosity change move it up and down a few rpms).
Secondary intake butterflies open at 6000rpm.
Vtec does not engage at 6000rpm. And you still will hear the note crossover with or without vtec working (if you only have an intake) But it will be sluggish.

Trust me. Having a dc2 with a straight pipe you can DEFINATELY tell the exhaust crossover note, and its at the 4500rpm mark. And exhaust crossover note cannot be heard with secondary intake butterflies. That only effects intake.


With stock air filter, and just the cover taken off it. You gotta have bats ears to hear the crossover at 4500rpm.
The revs are too low for any real notable change in sound. Even with cai or sri.


At the end of the day. Vtec at 4500RPM (differs by a few rpms with oil pressure, temp, viscosity, and all that mumbo jumbo)
Secondary butterflies are opened at 6000rpm.

This is spot on.
My crossover is pretty audible at 4400rpm then I cant really hear a crossover at 6000 probably due to my intake still boxed with ducting into the front guard

[Toilet]

When I took off my axle back to have it polished, I took my car for a drive, and for the first time since owning the car, the crossover at 4400rpm was like BAM!!@$!$!@%@
Before that, couldn't hear anything at 4400rpm.
With a cold air intake I could only hear this kinda crossover effect deepening sound at around 5800rpm. Sure found that pretty awesome...
Sorry, what's this discussion about? I lost track within the vtec talk