Supercharger on electromagnetic clutch

Do you know of anyone who has done this ?

I have a centrifugal supercharger so can't use a recirculating valve when the throttle is closed/partly-closed so it is always producing boost while the engine is turning. I have a twin dump valve setup to release the pressure.

This works well but gets quite annoying on a long drive (constant escaping air sound) so I end up driving it most of the time with a smaller utility belt to bypass the supercharger which is mighty embarrassing when big num pulls up next to you on a Luxembourg motorway and I am in NA mode.

So this got me thinking what I need is some way to switch the supercharger on when required so I started searching for a beefy 12v electromagnetic clutch and this is what I found

This looks quite chunky so with that bit of scientific research completed set about seeing how I could fit this somewhere under my bonnet where it could drive the supercharger.

looks like what's on a ac compressor

There is an MR2 with a clutch based charger setup. Maybe check out the MR2 forums

Alas after looking at every possibly I could see this was not going to fit so dismantled the unit and decided that it could be modified to fit

The body is just to wide but the shaft and bearings could be adapted to fit into a custom made body

This is how far I have got more pics to follow

What ecu are you using?

Something like a Syvecs, Emerald, Motec etc could engage/disengage the clutch, so you could have separate boost / no boost maps.

I have a Syvecs S6 and have 2 separate maps already NA and boosted

I switch between the 2 when changing drive belts so yes that is the plan to get the Ecu to output a 12v signal to activate the clutch unit when switching to boosted.

looks like what's on a ac compressor

Same kind of thing just a lot more beefy

I have a Syvecs S6 and have 2 separate maps already NA and boosted

 

I switch between the 2 when changing drive belts so yes that is the plan to get the Ecu to output a 12v signal to activate the clutch unit when switching to boosted.

Awesome

So now I've made a replacement for the plate with the idler pulleys and left enough metal to make a bracket for the new clutch housing

Don't SL55 AMG Mercedes use a clutched compressor? I have had such a car here for well over a year, I could have a look and see if it's clutched if you like? Is that clutch up to the shock loads and running torque? Not something i have ever played with, but you seem to know what you are doing

An electronic clutch will do the job like falling down a flight of stairs whilst wearing leg callipers, using a vacuum operated recirculation valve would be far better idea.

A Forge valve would reliably sort that.

FMDVECL202 http://www.forgemotorsport.com/search?q=FMDVECL202

An electronic clutch will do the job like falling down a flight of stairs whilst wearing leg callipers, using a vacuum operated recirculation valve would be far better idea.

 

A Forge valve would reliably sort that.

 

FMDVECL202 http://www.forgemotorsport.com/search?q=FMDVECL202

 

http://www.mkivsupra.net/vbb/vbpgimage.php?do=full&p=23356&d=1397771146

Where is it going to recirculate the air to? This is not like a roots type supercharger with the throttle body at the inlet side of the supercharger. The inlet side of the supercharger (apart from the air filter) is open to atmosphere, this is just like a belt driven turbo.

In that case, it would just increase the din, is it not possible to fit the clutch onto the supercharger pulley like some Merc's?

Don't SL55 AMG Mercedes use a clutched compressor? I have had such a car here for well over a year, I could have a look and see if it's clutched if you like? Is that clutch up to the shock loads and running torque? Not something i have ever played with, but you seem to know what you are doing

I know Mercedes do use a clutched compressor on at least one of their cars.

Not sure if the clutch I have is up to the job but it looks fairly beefy, and I only intend to engage it at low revs.

As to knowing what I'm doing well I'm just making it up as I go along

In that case, it would just increase the din, is it not possible to fit the clutch onto the supercharger pulley like some Merc's?

Because the flywheel pulley is quite small on the 1uz then the drive pulley on the supercharger has to to be very small and I'm fairly sure that a clutch that could take that amount of torque could not be made that small. So that's why I'm having the flywheel pulley driving the clutch and then the clutch driving the supercharger via a separate belt.

This also has the advantage that I can position the supercharger further back in the engine bay because it was quite tight to the radiator before.

New position will be here

Sounds awesome.

Great to see your constantly on the strive to try new things Steve.

Attached the clutch housing to the new idler plate assembly

A lot of Power Boats are both supercharged and Turbo My dads current boat has two supercharged and turbo engines.

Maybe you could look what components they use as it is common practice and they have huge TQ and HP outputs compared to cars.

Would love to take a look at that kind of setup. Have been thinking of a supercharger/turbo setup for a while. That's half the reason for wanting the clutch on the supercharger but don't tell the missus. She thinks I'm doing this for her so it's not so loud 

Would love to take a look at that kind of setup. Have been thinking of a supercharger/turbo setup for a while. That's half the reason for wanting the clutch on the supercharger but don't tell the missus. She thinks I'm doing this for her so it's not so loud 

Haha I suppose its all about space its not really an issue with most boats but a car would certainly be a technical achievement.

I know that our twin diesel engines are powered by superchargers until a clutch disengages them and the turbos take over.

It must be a robust setup as high rpms are constant on boats as apposed to a car.

Im not sure what gains can be had when complexity and cost are taken into account.

Nice twin charged Volvo here: http://www.gatesgarth.com/volvo_dyno/volvo_twincharged.jpg

http://www.gatesgarth.com/volvo_dyno/dyno_pull.mpg

Nice twin charged Volvo here: http://www.gatesgarth.com/volvo_dyno/volvo_twincharged.jpg

 

http://www.gatesgarth.com/volvo_dyno/dyno_pull.mpg

That is awesome. What coating is on the turbo manifold, looks like gold plate!

Would love to take a look at that kind of setup. Have been thinking of a supercharger/turbo setup for a while. That's half the reason for wanting the clutch on the supercharger but don't tell the missus. She thinks I'm doing this for her so it's not so loud 

Nissan mass produced a twincharged Micra that sold here in the UK. "Only" 110 BHP but thing was 770 kgs and somewhere on YouTube is one embarrassing a modified Supra MIV turbo at Samta Pod. A now retired engine builder friend, Sam Nelson of Nelson Engine Services was asked to develop this little engine for competition and Sam was getting about 300 BHP from them.

http://jalopnik.com/is-this-twincharged-nissan-the-most-forgotten-homologat-1653317711

Edit: here's the link to Micra V Supra