Mini supercharger on 1zz

Anonymous · June 27, 2016, 20:37

Quote from: "Carolyn"
Quote from: "rbuckingham"280 from memory a pe stands for power enterprise. They lifted the fuel a bar to 3 bar I think have to double check but 3 rings a bell. Stock system will correct within reason.

Personally if it was me I would pay the money and get an emerald ECU fitted and run a map system.

£700 for an emerald.

Yep but it's a standalone so up for the job regardless of the engine.

But as I knew you were budgeting I thought I would mention the PE kit method as it uses stock ECU and injectors. s:roll: :roll: s:roll:

lamcote · June 27, 2016, 21:07

Would a plastic water pump pulley be adequate or will it need to be metal?

Carolyn · June 27, 2016, 21:23

It's got to handle a lot of power, metal, I would think. I'll see if we can modify an idler pulley (has a bearing in it...)

lamcote · June 27, 2016, 21:37

Oh, isn't the bearing in the supercharger itself, I've been looking at lots of pulleys and they don't seem to have bearings in, they just have flat plates in the centre that bolt on to a shaft. I told you, you can't trust me with anything technical!

Carolyn · June 28, 2016, 07:28

- the idler pulley has a bearing in it. You're on the right track. We want ones without bearings.

Carolyn · June 28, 2016, 08:39

The end of the shaft is 19mm in diameter. Don't know if it's tapered or keyed or both. Going to have to pull it off.

It's an interference fit. I've found loads of smaller ones to increase boost. No bigger ones yet. going off this idea...

Carolyn · June 28, 2016, 09:17

We can also limit boost with the bypass valve, it's controllable.

shnazzle · June 28, 2016, 09:25

Quote from: "Carolyn"We can also limit boost with the bypass valve, it's controllable.

That's why I figured a manual boost controller would be an idea.
Just not sure how that works on a SC to be honest. Can you plumb a manual boost controller into the SC bypass valve? Or perhaps change the spring in the valve?

lamcote · June 28, 2016, 09:27

m http://www.bearingshopuk.co.uk/spa120-1 ... um-pulley/ m

Is this any good?

lamcote · June 28, 2016, 09:28

Is the bypass just on or off though, or does it have graduated adjustment?

Carolyn · June 28, 2016, 09:48

Don't know.

lamcote · June 28, 2016, 10:04

I suspect it will be on or off only as it's only really designed to be there to recirculate the air (and remove all boost) on part throttle to aid economy.

If so it can be used to switch the boost on or off, but not vary it like a wastegate would (subject to your hacking skills to make it do otherwise).

lamcote · June 28, 2016, 10:04

Any thoughts on the pulley I linked to?

Carolyn · June 28, 2016, 10:27

It needs to be a proper pulley for a ribbed belt. Not going to be easy to find a pulley by the looks of it. Manual boost control looks like a viable alternative.

lamcote · June 28, 2016, 10:37

Could Widermuller make a pulley, it's a bit like a bigger HVAC knob!

Carolyn · June 28, 2016, 10:58

We could make one...
I'm going to leave this all alone for a few days and mull things over. I'ts my wallet and I need to think it through..

shnazzle · June 28, 2016, 11:14

Quote from: "Carolyn"We could make one...
I'm going to leave this all alone for a few days and mull things over. I'ts my wallet and I need to think it through..

we've driven her to insanity already boys s:)

s:)
Retreat! RETREAT!

Good decision Carolyn. We'll all have a spy around to see what's what, bearing (no pun intended) in mind costs first and foremost.

From the looks of it, older american muscle cars are the best sources for larger SC pulleys it seems. So, that should narrow down the search. Perhaps forums for Dodge Chargers or Pontiac Firebirds?

lamcote · June 28, 2016, 11:21

Well spotted shnazzle, I'll keep looking and hope Carolyn and her wallet make friends again.

What are your specific concerns? Is it one or two specific elements being discussed or the whole project?

I'm sure we can find a way through one way or another.

If it helps, the way I see it is; we have some options for the engine:

1) Proceed without a piggyback ECU and with a 120mm pulley. Saves a wad of cash, nice challenge, but needs a lot of tinkering time and may not be successful.
2) Proceed by buying a piggyback ECU and use the standard pulley. Costs more, less challenge, but I reckon it guarantees success quite quickly.
3) Proceed by borrowing a piggyback ECU and use the standard pulley. Saves the cash but probably guarantees quick success. Win Win (but less challenge, other than finding the ECU somewhere)?

All of the above depend on the subframe development of course, are you still happy with this bit?

Anonymous · June 28, 2016, 12:39

a supercharger should be set to produce its max boost by sizing the pulley. the bypass valve is to be opened like on a turbo system to stop compressor stall. now compressor stall on a turbo makes noises and gives lag however on a supercharger it will be more catastrophic with the charger stopping and belts slipping

lamcote · June 28, 2016, 12:43

What causes compressor stall in a supercharger? Is it the throttle being closed suddenly when on boost?

If so does the by-pass valve have two purposes:
1. Prevent stall/surge when throttle is closed suddenly
2. Improve part throttle fuel economy by recirculating air (cutting boost) in low load cruising

Thanks

Anonymous · June 28, 2016, 16:21

Correct

Essex2Visuvesi · June 28, 2016, 23:13

If you have some specs of the pulley (fag packet sketch with dimensions will suffice) I'll see what I can come up with

lamcote · June 29, 2016, 08:04

SC pulley is 65.5mm. Mini crank pulley is 138.7mm. This apparently gives around 10.5-11psi on the 1.6l Mini.
I have estimated that the same SC pulley on the 1.8l 1zz with a 135mm crank pulley will give around 8.5psi. Both engines redline at 6,800.
What do you reckon?
Thanks

Carolyn · June 29, 2016, 08:09

The SC pulley is interference fit on a 19 mm shaft. The outer surface is for a standard 5 groove flat belt. Lamcote: How have you calculated pulley sizes? Perhaps you can post the target RPM for the SC and we can check your calcs. Still mulling it over....

lamcote · June 29, 2016, 09:09

The simple version is:

1.6l is 0.88888 of 1.8l
138.7/65.5 = 2.12 and 135/65.5 = 2.06
2.06/2.12 = 0.97
10.5psi * 0.888 * 0.97 = 9psi
Assume our layout is 5% less efficient than the OEM Mini
9 * .95 = 8.5psi

If you look up the proper way to calculate pulley ratios it seems to pretty much tally with this outcome.

The internet says the M45 shouldn't spin past 14,000rpm at peak power. It is safe to higher revs (16,000?) but it is not efficient beyond 14,000.

The standard Mini M45 spins at 11,660rpm at peak power and with aftermarket 15% pulleys spins at 13,409rpm at peak power of 5,500.

1zz would spin it at 13,184rpm at its peak power revs of 6,400.