just something i noticed when i was bored in the driveway

wdkwang · 03-05-2011, 03:21 PM

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

AllForTheCash · 03-05-2011, 03:52 PM

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

DIGItonium · 03-05-2011, 03:55 PM

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.

6MT · 03-05-2011, 03:58 PM

Quote:

Originally Posted by DIGItonium

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.

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

wdkwang · 03-05-2011, 04:03 PM

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

6MT · 03-05-2011, 04:04 PM

Not really. I like that, though.

SPOHN · 03-05-2011, 04:14 PM

Quote:

Originally Posted by DIGItonium

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.

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.

chuckd05 · 03-05-2011, 04:14 PM

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.

ImportConvert · 03-05-2011, 06:34 PM

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.

kenchan · 03-05-2011, 07:48 PM

My z does the same. You're fine.

christian370z · 03-05-2011, 07:56 PM

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

1slow370 · 03-06-2011, 02:31 AM

Quote:

Originally Posted by ImportConvert

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.

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

thugstatZ · 08-12-2011, 09:57 AM

Quote:

Originally Posted by chuckd05

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.

SPOHN · 08-12-2011, 10:05 AM

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

jpritche · 08-12-2011, 10:08 AM

Quote:

Originally Posted by SPOHN

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

03-05-2011, 03:21 PM	#1 (permalink)
wdkwang Track Member Join Date: Nov 2010 Location: N/A Posts: 899 Drives: slidewayz Rep Power: 21	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 __________________ Powerhouse Amuse \| K&N Typhoon Intakes \| MotorDyne ART Pipes \| Borla Catback Exhaust \| B&M Short Shifter \| Intake Ducts \| Ichiba 25mm F/R Spacers \| Carbon Fiber Interior Vinyl Wrap \| Tints \| 10000k HIDs \| Vtak, yo!

03-05-2011, 03:52 PM	#2 (permalink)
AllForTheCash Enthusiast Member Join Date: Sep 2010 Location: NJ Posts: 385 Drives: 370z Rep Power: 15	I think I have noticed the same thing. It "pauses" for a second then continues to drop... __________________ 2010 370z Brilliant Silver/Frost - Touring - Sport - Navigation - 6MT

03-05-2011, 03:55 PM	#3 (permalink)
DIGItonium A True Z Fanatic Join Date: Jan 2009 Location: Kansas Posts: 3,800 Drives: 09 Z34-TT 6MT Rep Power: 42	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. __________________

03-05-2011, 04:03 PM	#5 (permalink)
wdkwang Track Member Join Date: Nov 2010 Location: N/A Posts: 899 Drives: slidewayz Rep Power: 21	i was thinking about full boltons but i really dont want the hiss. is there anyway around that? __________________ Powerhouse Amuse \| K&N Typhoon Intakes \| MotorDyne ART Pipes \| Borla Catback Exhaust \| B&M Short Shifter \| Intake Ducts \| Ichiba 25mm F/R Spacers \| Carbon Fiber Interior Vinyl Wrap \| Tints \| 10000k HIDs \| Vtak, yo!

03-05-2011, 04:04 PM	#6 (permalink)
6MT A True Z Fanatic Join Date: May 2009 Location: ITU Zone 2 Posts: 22,459 Drives: Reliant Robin Rep Power: 1790	Not really. I like that, though. __________________ Andrew 2009 370Z Sport/Touring 6MT sold 2013 Honda Civic Si coupe D/D

03-05-2011, 04:14 PM	#8 (permalink)
chuckd05 A True Z Fanatic Join Date: Oct 2009 Location: NY Posts: 2,391 Drives: No longer a Z Rep Power: 20	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. __________________ 09 370Z 6M PW - FBO Best 1/4 mile = 12.926 @ 109 SOLD -- 08 BMW 135i - FBO 12.1@120mph SOLD -- white 09 e92 335 Coupe Mtech - 11.9 @ 119 :-)

03-05-2011, 06:34 PM	#9 (permalink)
ImportConvert A True Z Fanatic Join Date: Jun 2010 Location: SWMO Posts: 4,454 Drives: 2019 CX5 GT Reserve Rep Power: 7627	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.

03-05-2011, 07:48 PM	#10 (permalink)
kenchan A True Z Fanatic Join Date: Aug 2009 Location: N/A Posts: 76,801 Drives: N/A Rep Power: 141521	My z does the same. You're fine.

03-05-2011, 07:56 PM	#11 (permalink)
christian370z A True Z Fanatic Join Date: Jul 2010 Location: Newport Beach Posts: 3,900 Drives: 2010 370Z/Saab 900se Rep Power: 432	It never really bothered me, but I'm happy this thread got started as I did not know what the reasoning is behind it. __________________ -320whp / 259wftlbs- SP Rays -- RE-11s -- SpecialtyZ Tune -- Swift Springs -- Stillen 25R Oil Cooler -- Stillen G3 Intakes -- Berk HFCs -- F.I. 12" CBE -- Stillen Sway Bars -- Es14 Spring -- INGS+1 lip -- CF Spoiler -- GTR Start Button -- VLED Parking Lights -- PWJDM V2 shift knob

08-12-2011, 10:05 AM	#14 (permalink)
SPOHN A True Z Fanatic Join Date: Feb 2010 Location: Covington, GA Age: 45 Posts: 14,844 Drives: Waiting on next Z Rep Power: 221	What is your reasoning for bring this thread back? To mock someone. Real mature newbie. __________________

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