Is the Tomei supposed to hiss?

Rhasenbank88 · 08-01-2019, 07:08 AM

Hey guys, recently purchased a Full Tomei exhaust with the Tomei y pipe and had a shop install it since I don’t really have any tool. Fitment seems good and everything but I do have a weird hissing sound mostly on deceleration. I thought that normally you only get the “hiss” with test pipes. My cats are stock with just a Tomei, is this normal?

Chuck33079 · 08-01-2019, 07:28 AM

That's just the sound of the motor. Completely normal. If you think it's bad now, wait until you get test pipes.

Rusty · 08-01-2019, 05:19 PM

Embrace the hiss. It makes the Z different.

It really confuses other people on what's going on.

Maestro666 · 08-05-2019, 05:51 PM

I have a theory that the hissing is caused by vibration of the exhaust piping when you hit a certain frequency. The hissing gets louder as you change out exhaust components, not because you are freeing up exhaust flow, but because you are changing to piping that vibrates more freely.

You could test this theory by jacking the car up and clamping some heavy weight to the most exposed section of the exhaust.

Eagle · 08-05-2019, 07:13 PM

I can confirm my Tomei hisses on deceleration as well, full exhaust + y-pipe and test pipes. I've heard that the only way to reduce this to a minimum is by running the Motordyne ART pipes instead or by running cats.

Rusty · 08-05-2019, 08:42 PM

Quote:

Originally Posted by Maestro666

I have a theory that the hissing is caused by vibration of the exhaust piping when you hit a certain frequency. The hissing gets louder as you change out exhaust components, not because you are freeing up exhaust flow, but because you are changing to piping that vibrates more freely.

You could test this theory by jacking the car up and clamping some heavy weight to the most exposed section of the exhaust.

There is a couple of old threads on the hiss. The throttle blades go wide open just off idle. The speed is controlled by inlet valve lift and injector dwell time. The hiss comes from the throttle blades being open and no fuel being injected. Creating vacuum being pulled through the throttle bodies. That's what I read any way.

08-01-2019, 07:08 AM	#1 (permalink)
Rhasenbank88 Base Member Join Date: Mar 2017 Location: Cedar Lake, IN Posts: 10 Drives: 2017 370z m6 Rep Power: 8	Is the Tomei supposed to hiss? Hey guys, recently purchased a Full Tomei exhaust with the Tomei y pipe and had a shop install it since I don’t really have any tool. Fitment seems good and everything but I do have a weird hissing sound mostly on deceleration. I thought that normally you only get the “hiss” with test pipes. My cats are stock with just a Tomei, is this normal?

08-01-2019, 07:28 AM	#2 (permalink)
Chuck33079 A True Z Fanatic Join Date: Nov 2011 Location: Houston Posts: 12,265 Drives: 2011 370ztt Rep Power: 29538	That's just the sound of the motor. Completely normal. If you think it's bad now, wait until you get test pipes. wideglideleon likes this. __________________ 2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

08-01-2019, 05:19 PM	#3 (permalink)
Rusty Ronin Samurai - Assassin Join Date: Dec 2011 Location: Fayettenam,Pennsyltucky Age: 68 Posts: 34,859 Drives: 2011 Nismo GM 6M Rep Power: 2684436	Embrace the hiss. It makes the Z different. It really confuses other people on what's going on. Mike_O_Nite likes this. __________________ 浪人 - 殺し屋 "The Difficult Anytime, The Impossible By Appointment Only" http://www.the370z.com/members-370z-...o-journal.html

08-05-2019, 05:51 PM	#4 (permalink)
Maestro666 Base Member Join Date: Oct 2018 Location: Australia Posts: 99 Drives: 370z 7AT 2014 Rep Power: 6	I have a theory that the hissing is caused by vibration of the exhaust piping when you hit a certain frequency. The hissing gets louder as you change out exhaust components, not because you are freeing up exhaust flow, but because you are changing to piping that vibrates more freely. You could test this theory by jacking the car up and clamping some heavy weight to the most exposed section of the exhaust. Eagle likes this.

08-05-2019, 07:13 PM	#5 (permalink)
Eagle Track Member Join Date: Jan 2011 Location: South Orange County, CA Posts: 884 Drives: 2011 370z Red 6MT Rep Power: 10656	I can confirm my Tomei hisses on deceleration as well, full exhaust + y-pipe and test pipes. I've heard that the only way to reduce this to a minimum is by running the Motordyne ART pipes instead or by running cats. __________________ nismo\| EVO-R High Wing \| *Stillen* Gen 3 CAI \| SEIBON TS Hood \| Z1 34 Row Oil Cooler \| VMR 810 Wheels \| Endless MX72 Pads \|*Sabelt* GT-140 Seat \|Fly1Motorsports RS1 Fenders \| Hotchkis Front Sway Bar \| Berk HFC \|

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