Supercharger Whine

[Dr.Drew]

This might be a dumb question but why exactly do superchargers whine? I read on an old hotrod forum that it's the air being trapped against the pulley by the belt but if that were true why doesn't a power steering pulley whine? They also said belt tension will increase whine.

I've noticed that my blower is relatively quiet. It doesn't really start to whine till higher RPMs and as soon as I let off the sound stops. However the s/c'ed Miatas on Youtube and Leeboat's car has a loud and distinctive whine to it.

I know it's vain but I would like a little more sound from it but not at the expense of over tightening the belt and frying my blower bearings.

[Cool Cat Racing]

One they're driven by straight cut gears which will always whine. Second, as the teeth of the supercharger mesh together they create the same type of noise. Power steering pumps do whine but the fluid dampens it more than air does.

[FooSchnickens]

straight cut gears
mmmmmmm... delicious dog box

dmJH84FnQa8

[Beastinthebushes]

mmmmmmm... delicious dog box

dmJH84FnQa8


Holy **** that is loud

[Dr.Drew]

One they're driven by straight cut gears which will always whine. Second, as the teeth of the supercharger mesh together they create the same type of noise. Power steering pumps do whine but the fluid dampens it more than air does.

Ok, cool. I didn't know that.

So I guess the volume of whine is more about the unit, some whine more than others.

[Beastinthebushes]

So I guess the volume of whine is more about the unit, some whine more than others.

Not sure if this is true Drew. You whine a lot, and your unit is tiny.

[Doppelgänger]

It's the sound of the air crying as it's being compressed.
The more open the intake tract is, the louder it will be.

[darknessprevails]

cog valve FTW

[Dr.Drew]

cog valve FTW

???

[darknessprevails]

A COG belt is a belt with teeth. That is instead of a smooth belt, such as a simple v-belt, that will always have some slip, and whose drive ratio is then only a close approximate ratio, a "COGGED" belt has teeth, so that the drive ratio is an exact value based on the number of teeth in each pulley (or sprocket) that the belt passes over.

Toothed belts also permit much higher torque to be driven than not toothed belts.

So, the COG number of a pulley is the number of teeth in the pully.


Idk why i said cog valve ?!?!

but it something alot of the stupidcharger camaro folks i ve heard do to incress the whine from the charger

[mustangtomiata]

supercharger whine gets louder as boost goes up to.

[shadow102]

cogged/tooth belt

YouTube- gilmer 008

[FE3tMX5]

It's the sound of the air crying as it's being compressed.
Or is it the sound of the driver crying as the turbo'd car drives away? :p

[Jack-MX5ATLanta.com]

You've got an M45 right? Mine used to scream like a banshee. What intake are you using?

[Dr.Drew]

I've just got the regular elbow that comes in the kit, some pipe, and a cone filter. Most 45's do, mine just doesn't. Strangest thing.

[Jack-MX5ATLanta.com]

I remember having to tighten the allen head bolts on the top of the intake plenum thing, maybe you've got a little leak and it's not air tight? I dunno, just throwing ideas out there now.

[Dr.Drew]

I don't think I have a leak, my boost is pretty solid and I just went out and the bolts seemed quite tight.

I never heard the unit when it was on Dave's car so I don't know if it was louder then but I'm getting the impression that some units are just louder than others. It's not a big deal I was just wondering if there was a way to make them louder ;)

[Cool Cat Racing]

They will whine more as the boost increases because the RPM's increase. If you've got a system like I setup with out moving the TB then you'll hear plenty of whine. Just ask Lee or Frohock. lol

[Dr.Drew]

Well I thought about moving my tb back to stock position and adding a blowoff valve but I don't want to pay for re-drillig and tapping for my iat and WI nozzle. I have ridden in Lees car and it's a beast!

But, I just changed out the air filter and reworked some of my intercooler piping and was rewarded with a whole pound of boost!! I'm noe consistantly staying at 7lbs even in this weather. It didn't increase whine but I'd rather have the extra pound.

I also noticed that my boost doesn't start dropping till 6500 rpm which seems better than before.

But I do have one question: at full boost I'm occasionally hearing an audible ticking sound. I think it's the plunger thing that operates the bypass valve. When it happens the boost gauge vibrates a little.

It only happens under full throttle and only occasionally but do you guys think it's time for a new plunger thing?

[Jack-MX5ATLanta.com]

It doesn't sound like metal bb's shot into a tin can does it? Because that's pinging and normally means you need to pull the timing back a little.

[Dr.Drew]

No, it's not detonation, it's more of a click and I pulled my plugs yesterday and there's no sign on det.

Plus I haven't done any tuning to the spark table and the base map from DIY is stupid conservative.

[Cool Cat Racing]

If its a single tick then its probably the bypass valve. You can also check the piece the bypass valve attaches too on the supercharger valve itself. I've had to replace a few on customers cars since the rod on the bypass valve is chromed and the steel rotator piece it attaches to is just regular steel it will wear it away and cause some slop. Its available from JR and is easy to swap. When I did the setup on my old car/Lee's car I never thought it would have all the affects it did but after that I had lots of other people wanting me to do it for them as well.

[Dr.Drew]

It usually ticks 4 or 5 times when it happens. I remember mike telling me about a piece you could get that prevents it from wearing down but I don't remember the name.

I was once told that you had to open up the blower to replace that bit.