just something i noticed when i was bored in the driveway
 

i pulled in and just sat in the car slowly revving the motor to 2-3k rpm, as to not wake up people.
correct me if i'm wrong but you can actually hear the back pressure as the rpm's fall but something more interesting is every time the rpms fall to 1.5k, it stays there for a short moment n then continues to fall to idle rpm. never seen that happen in other cars before. what's up with that?

thumbs up if i just got you to go rev ur z after reading this :ugh2:

I think I have noticed the same thing. It "pauses" for a second then continues to drop...

That's normal. I think the ECU does that for emissions. If you install HFC, you can really hear the "hiss." It's pretty entertaining.

:iagree: I wondered what it was over a year ago too. The HFC's really make it loud too.

i was thinking about full boltons but i really dont want the hiss. is there anyway around that?

Not really. I like that, though.

I was told that also at one time. If I remember right, I was told that when you come out of the throttle the injectors shut down which also causes a lean condition to help with emissions.

On my old g35 coupe I got a greedy evo2 exhaust and it was hiss free after adding res test pipes. But all the exhausts for the 370z develop the hiss after hfc or test pipes from what I understand.

Like others have said, it's normal. The IAC allows some air in and the revs hang and it helps burn off fuel a bit better. I experimented with this on my 5.0 by blocking off the IAC, and then removing it all togather when I went carb.

My z does the same. You're fine. :)

It never really bothered me, but I'm happy this thread got started as I did not know what the reasoning is behind it.

there is no iac!!! j/k not jumpin ur shat or anything but the ETB's do all that fun stuff

:icon18:

What is your reasoning for bring this thread back? To mock someone. Real mature newbie.

:iagree: