Has anyone supercharged a zetec engine before? or have any experience with a supercharger?

Mine wines soooooo much even on idle. Its an Eaton M62 from a Merc CLK. Ive changed the cone filter and put an OEM CLK airbox on but its still loud. Here is a video done by the previous owner. It is still this loud. Any ideas?


It failed noise test at bedford on both static and drive by. I have repacked the exhaust with Acousta-fil but think the issue is the Superchrger whine. A mate has a supercharged Atom and its so quiet compared to mine

Supercharger

[Edited on 9/7/19 by number-1]

Hi, Where is your throttle body? I run an S/C on my MX5, T/B is pre-charger. Virtually silent until you wind it past 4500, even then it is only a subdued whine. I have no experience but I am told by other MX5 owners that a post charger T/B can be extremely loud, not sure I understand why but must have something to do with the acoustics of an undamped S/C.

I bought the car as it is so don't have too much knowledge of the ins and outs however the previous owner (who installed the SC) said there are 2 Tbs...1 before the SC and 1 after

It should only whine loudly when it's boosting, it's possible that the bypass is sticking closed.

The inlet manifold TB's should open before the air filter side one or the air will back up making noise, when running flat out they can be very noisy anyway, my M90 howls.

That's loud

It is definitely ALL caused by the supercharger ?

You can’t hear the Eaton M45 on my car at all until it comes on boost - +1 for check the bypass isn’t stuck.

Cheers for the replies chaps.

I changed the cone filter and stuck an OEM merc airbox and filter and its made a small difference but listening to it today the noise is coming from the supercharger.

I will try and find the bypass and check it during the week.

From reading the build thread on another forum, the supercharger has been modded so its a direct drive pulley and not a clutch pulley? Not too sure if this makes a difference?

What does the interface plate look like between sc and manifold. And has someone "improved" it by blanking the pressure relief holes in the sc outlet?

Clutch removal is fine, just stops it stirring at low throttle to improve economy, less drag off the crank.

iirc this has a dual throttle body setup. Also, i think it has a switch designed to activate a boost control solenoid to bleed off boost when cruising as previous owner had issues at cruise.

EDIT: Found his post about it https://www.rhocar.org/index.php?/forums/topic/45912-supercharger-boost-control/&tab=comments#comment-376761

[Edited on 10/7/19 by theduck]

Yeah mine is the same car. There’s a switch fitted as per the link above. However, the engine noise is like it on both settings.

Anyone know the benefit from having the dual throttle body set up?

The car is mainly for trackdays but I’ll be using it to drive too and from so not too fussed on general drive ability as the old owner was.

I've got a supercharged 5.4 v8 and it's barely audible on idle
You have to rev it to make its noise ..
That's not right surely

quote:

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Originally posted by number-1
Anyone know the benefit from having the dual throttle body set up?

The car is mainly for trackdays but I’ll be using it to drive too and from so not too fussed on general drive ability as the old owner was.

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Sounds like a choir boy going between B and C. Sorry can't help on the diagnosis

Thanks once again for the replies chaps. When im off next week ill test the bypass release valve and go from there. If that seems ok i will try and use one throttle body as most people i know only use 1.

I will keep you posted.

Probably a daft question, but is it using standard pulleys and ratios?
If it was spinning too fast at idle it might make it noisy...?

Ive just had a read on the original build thread which can be fund here if anyone is curious Supercharged thread

From reading it....the Supercharger pulley is 55mm as it was changed to a direct drive charger as the original 90mm pulley was heavy and had poor ratios

Apparently it now has 2.3 pulley ratio

[Edited on 12/7/19 by number-1]

Well, i had some time yesterday and took stuff apart and checked the bypass valve and seems to be ok. I pushed the operating leg upwards and placed my thumb over the top intake and the butterfly held open and didn't drop so presume its good?

So then I decided to remove the 2nd TB....well....the butterfly at least (1st is just before the charger and 2nd just before the engine intake plenum) and see what happened. Ive obviously done something wrong as as soon as the car is started it goes to wide open throttle with the butterfly removed from the 2nd one!!!!

The 1st TB before the charger seems to be working as it is almost closed when the car is off however has no sensor on top....i presume its the TPS sensor. I think i will try again but with a sensor fitted to the 1st TB and leave the second as it is without the butterfly or sensor

Any obvious errors to my plan??

Doesn't take much air to go redline with no load. I assume your first tb is the safety tb to reduce pumping losses and stop the sc popping the second throttle. As such, the first tb will be "a bit" open while revs accurately controlled by second butterfly?

In fairness.....everything i put back...... i didnt tighten right up.....it was loose fitted......very loose lol

In relation to the 1st TB.......to be honest..... i have no idea? Its connected to the accelerator but there is no sensor on it nor any wiring going to it. The only TB that has a TPS and wiring is the second

Do you have an airbox?
What is it made of?
To me it sounds like "oil canning"...
I have never heard a supercharged motor running with the bonnet opened, So This is only a blind man´s guess....

It had a cone filter with no air box on, so fitted an ITG air box ( ali ), then an OEM SLK airbox ( plastic ) and still no difference.

Custom pulley you say.... Right tooth profile?

I have very similar noise coming from the slightly mismatched timing belt pulley tooth profile on my cnc machine spindle.

When I supercharged my mx5 engine I used 2 throttle bodies. One on the inlet in the original position the other on the inlet to the SC. They were linked together, then to the throttle pedal. The cable to the TB on the inlet had a slightly cammed wheel so it opened slightly faster than the one on the SC. If they are out of sync or the SC one opens before the inlet one then it makes the SC louder. The Inlet TB was slightly cracked open at idle (a tiny fraction)

The reason for 2 was due to the long inlet from sc through intercooler to TB. Without the one on the inlet throttle response was sluggish and coming off throttle could cause the car to nearly stall.

The system also had a bypass (mini) linked to vacuum so the SC only boosts under decent throttle input. The vacuum was taken from the inlet after the 2nd TB, not the usual mini position. Where is your vacuum plumbed?

A loud SC often means the bypass isn't working properly or at all and it's boosting constantly against a closed/ mostly closed throttle butterfly. This makes it loud and can damage the SC due to back pressure.

My TPS was left in the original position on the inlet.

Properly set up you couldn't tell it was supercharged cruising on a light throttle. As soon as you open the throttle it made it's self known but not so loud it failed a drive by on track.

Most of the noise comes out of the filter like a megaphone, so after you have it all set up properly, using an OE airbox will quieten it down again. I used a cone filter but insulated the pipework which worked well.

U2U an email and I can send you some pics if that might help?

Top man. I will send you a U2U now.