WarmFreedom

hey guys,

ive searched the forum but none quite address my curiosity so here goes,

at around 4.5K rpm to 6.5K rpm, there is a distinctive sound (apart from engine humming) of jet engine.

my question is;

whats responsible for this sound? is it the air intake? or what?

the thing is, its like music to my ears i.e. very cool. so what can i do that would make the jet engine sound louder?

SayNoToPistons

iTrader: (8)

6 ports just kicked in yo!!!

mysql101

drive in tunnels to make it sound louder.

WarmFreedom

well im looking for a more independant solution, but thanks anyway, riceguy. and besides ive tried driving next to a wall with the windows down, cant hear any of that whistling coming fr outside.

mysql101

You're not going to get what you want. If you want more sounds of a similar vein, you'll have to get FI.

JeRKy 8 Owner

Any type of mod you do will drown it out. Exhaust, intake, midpipe...the "jet" sound is ruined if you try to mess with any of that. As mentioned above, your best bet is WOT in a tunnel.

WarmFreedom

yeah thanks...but what makes that sound?

mysql101

I'm going to take a wild guess and say it's the SDAIS you're hearing. They open at 3700, 5500, 6200 and 7200 rpm.

'87 Turbo II

SDAIS? Super Duper Auxilery Intake System?
I tried. I'd asume it's your auxilery ports.

Raptor2k

Isn't 3200 instead of 3700?

mysql101

Sequential Dynamic Air Intake System


3750 is the actual number

Raptor2k

I could of sworn it was 3250, and I read somewhere that's how it is with the recent flashes. I also hear the marbles if I cruise on the highway at 3250.

ken-x8

Close, and the right idea. Sequential Dynamic Air Induction System. Three intake ports per rotor, two air intakes, various connecting ducts and valves. As RPM climbs, more of the ducts open. The higher RPM modes involve resonances in the system.

Ken

'87 Turbo II

Yeah I know the general workings of it, just didn't know the name. The 4 always open ports (2 per rotor) and 2 auxilery reffered to as 5th and 6th ports make the 3rd per rotor. See I know. Kinda.

mysql101

looks like you get 2 ports till 3750, then you get 4. 6250 is when you get 6

ZoomZoomH

iTrader: (1)

the Racing Beat intake + air duct makes teh jet sound nice and loud, i <3 it

ZoomZoomH

iTrader: (1)

just the intake though, any aftermarket exhaust will cover that wonderful sound lol

yiksing

Is that a problem? the marbles

Raptor2k

It's not a problem from what I know. And from what I know, I get the sound at 3250 and 7250, so I'm assuming that's when the ports open.

WarmFreedom

now that makes real sense, cos i hear the sounds change as the revs climb, it gets higher pitch with every transition of rev range.... that has to be it

WarmFreedom

cool cool cool, thanks man. thats what im talking about.

but let me see... the intake, would be referring to the air cleaner..
and the air duct would be???

are u reffering to this?
http://www.racingbeat.com/REVi.htm

MTLbroker

afterburners.......

ZoomZoomH

iTrader: (1)

that's the intake, this is the air duct:

http://www.racingbeat.com/resultset....rtNumber=18298

JeRKy 8 Owner

I disagree. The Revi intake and air duct do not "enhance" the actual jet sound. When you install those, you get a deeper and louder effect, but it's not the same crisp jet sound that you hear on a stock 8.

prescriptionmazda

haha, true story:
A friend got into my car for the first time, and heard this sound and seriously asked me if my car had a jet engine!

He's not too bright...