I was curious to know that if when you switch from an oem flywheel to a lightened aluminum flywheel, does it make the whine produced from the SC significantly quieter because of less parasitic drag? I have had my clutch, flywheel, slave & master cyl.s replaced and now that I have gotten past my 600 mile break in period I have noticed that the whine is way quieter than before. So Im wondering if it s from the flywheel or if I do have a leak at the SC. I get a weird fluttering noise only when driving/boosting on passenger side, its not an exhaust leak or anything that would throw a code, Ive done the hose to the ear check on about everything and nothing has shown its face.

Thanks for the input

 

is a function of the SC, not the flywheel at all! Only difference the flywheel will make is a really low engine speed (read idle) when it smooths out the crank rotation. Other than that, any difference in SC whine you hear is because of changes someplace other than the flywheel.

Matt

 

Hmmmm... then why the loss in noise from the SC after a clutch, power steering system, ball joints, thermo and gasket,valve cover & oil pan gasket replacement? The mech did nothing with the SC except to remove the belt and replace the SC inlet gasket (that small green oval looking thing).

Im so rattled trying to figure this out.

Thanks!

 

I am not positive of this, but I would think with the engine turning less weight with the lighter flywheel it is less of a load and that would quite down the Supercharger.

 

Thats what Im thinking too.

 

Parasitic drag is a function of the energy it takes to compress the air in the SC....sounds like maybe a belt that was out of alighnment was fixed, or maybe a noisy part, perhaps the throwout bearing was replaced...so the noise went away. When a light-weight flywheel in installed, noise, vibration, and harshness usually will go up due to going to a non-dualmass flywheel...and the car is eassier to stall when launching on a hill, or in traffic, but it does help a bit with motor response.

 

Would not affect the supercharger in any way......

Maybe the mechanic just tightened up some stuff that was loose, or aligned something better so there's less whine?

 

Maybe the additional whine you heard earlier was a leaking SC inlet gasket.

BTW, the mass (aka weight) of the flywheel does not affect the "load" placed on the engine once it's reached the target rotational speed (RPM). Apart from idling, the mass will only affect the engine's performance during RPM changes...

 

it was the belt swap.

Think about this. If the SC is unchanged before and after the work, what would be different in it that would cause anything? Nothing is different in the SC..... So I'm not surprised that you're stumped in coming up with an explanation as to why the changes made the SC operate differently. It didn't. The change in noise is from something else...

Matt

 

yes the throwout bearing was replaced along with just about everything else for clutch, slave, master cyl, main seal etc.. The noise definitely does not come from the throwout bearing, it was supercharger whine. The removal(not replaced with new belt)of the belt or the inlet gasket sounds a lil more on track. Ill check the belt and pulley when I do the second attempt on the tensioner stop cable.

Thanks a ton everyone!

 

any time it comes off it should be replaced. It's what, $15 or so? If you loose it while driving you're dead in the water. Also, as they age, they stretch and this will cause slippage on the SC pulley at very high RPM, robbing you of power. While Mini doesn't do this, it should be replaced every year.

Matt

 

Good to know. Im going to replace it when I rotate tires and put the tensioner cable on.

Thanks

 

I know Ive seen the item # before in a thread but i cant pin point it in the archive. But what is the napa part # and/or size for the Drive belt with a 15% pulley?

 

^ NAPA 060535

 

Thanks!

 

Perhaps the reduction in whine is that you are opening the throttle plate less during acceleration in response to the lightened flywheel? I don't know what a lightened flywheel feels like to drive on since I don't have one, but I suspect that since the engine needs less power to spin one up, you'd probably be less inclined to bury your foot in it.

Are you going WOT when you notice the reduction in sound?

 

Before the flywheel it would scream at mid RPM or even a good rev. But since the change there is a 50% loss in sound even at WOT.... may be a sc issue, not certain.