just installed my injen, is it normal to...

[^tyrant^]

ok i just got done installing my injen and i didnt rush the job wanted to make sure i did it right. after i was done i started the car to check everything out and i noticed when i turn it off i hear what sounds like a hiss sound. I know when i had my 93 teg with a CAI it made a small pop sound when i turned it off. i just want to know if the sound its making is normal.

[SpeedMcheen]

I just installed my Injen CAI last night, and I get the same thing. I think it's normal. The more HISSS the better.

[^tyrant^]

ok, i guess it is normal if you are getting it also, i doubt that 2 people installed it the same way wrong.

[DiscreetSpeed]

yes sir its a normal thing.

[CommieSpeed]

Did you all get a rubber sound dampening ring with your Injen?

[VegasMSP]

Hisssssss! It's normal! Hisssssssss! :D

[SpeedMcheen]

I definatley installed it right, and I love it. Now I'm trying to figure out what the shit causes the actual turkey to sound louder with it on. This forums seems totally split.

[SpeedMcheen]

I got a rubber. You want the part no.

Also got a cool Injen licence plate frame

[tiwing]

I definatley installed it right, and I love it. Now I'm trying to figure out what the shit causes the actual turkey to sound louder with it on. This forums seems totally split.

What causes the sound isn't in the air - it's definitely compressor surge. the only explanation I've read on here for why it's louder with the CAI is that the plastic damped the sound and the aluminum doesn't...

[SpeedMcheen]

So does the CAI happen to worsen the compressor surge, or would the surge (turkey) remain the same as if stock and just sound louder?

[Hypnotized]

It doesnt worsen, its just more audible with the intake.

[JDM Sam]

The noise is the air going into a narrow return tube. Blow air in the bpv return pipe of the injen and see if it makes noise. It's like blowing on the top of a glass soda bottle.

[Black Majik MSP]

What causes the sound isn't in the air - it's definitely compressor surge. the only explanation I've read on here for why it's louder with the CAI is that the plastic damped the sound and the aluminum doesn't...

So how do you explain that Billet Design's SRI (which is also aluminum & has a shorter pipe, thus giving the sound a shorter path to travel) doesn't amplify the turkey like the Injen does?

[03MSP]

Normal sound. My cousins RSX had it when he had his short ram, and I had it on my MX-6...just unused air excaping I think.

[GA_MZDASPEED]

when the engine stops ..at least 1 cyl is on the compression stroke......the hisssss is this compressed air "leaking down" past the rings....or seeping past a slightly open valve.....there is always leak down even in the best engine...........most factory air boxes will mask this sound.........aftermarket does NOT

[^tyrant^]

i bought mine retail and i did not get the rubber thing, and also i take it when you hit boost its normal to here it sucking air like a mofo

[SpeedMcheen]

I don't think that's true GA_MZDASPEED, there is no way that Hiss can travel that far back through all that tubing, intercooler, turbo and still sound. Once the engine stops and one cyl's intake valve is still open, it's exhaust valve is not open. So the air can't seep through a cylinder when the engine is off. So the pressure has no where to go but backwards out the intake, and the HISS occurs at the filter.

^ Tyrant ^

You should call Injen and tell them your CAI kit came without the vibra-mount and hardware and they should send it to you. If not then buy the pieces, I think it helps. Here's the three pieces and part nos. that I have for the vibra-mount to work.

1 - Vibrat-Mount P/N 6020
1 - Fender Washer P/N 6010
1 - m6 Nut P/N 6002

My Injen sucks so good!

[GA_MZDASPEED]

have you ever , as a kid taken the cardboard tube from wrapping paper and put it up to your mouth and made sounds..........the sound only come out the other end........the factory air box is MADE to absorb sound and the new injen w/metal pipes will absorb almost nothing............(this is all assuming we're still talking about the Hissing sound AFTER the car is turned off.) to reproduce this try rotating the engine w/ a breaker bar at the crank pulley (make sure you turn the right way) ....you will feel resistance on the commpression strokes and you will here the hissing......

[Dr.Sound]

i think it's the turbo spinning down.

some cars' turbos spin for about a minute after u turn them off....

[03MSP]

i think it's the turbo spinning down.

some cars' turbos spin for about a minute after u turn them off....

It's definitely not the turbo. My cousins RSX did it before he had his turbo, and my MX-6 did it before it had it's turbo; however, I did hear that BB turbos spin quite a while after being spooled.

[t3ase]

Almost *any* car I've seen with a CAI had ths hissing when you turn off the car. Sounds kinda cool, IMO.

[03MSP]

Almost *any* car I've seen with a CAI had ths hissing when you turn off the car. Sounds kinda cool, IMO.

I agree, sounds cool; I think it is more audible with an SRI.

[GA_MZDASPEED]

no turbos..........still a hissin.........i might actually be right .......don't tell my girlfriend....she'll never believe it (yippy)