Efficiency. The blower can only spin so fast ya know Well, until it stops making power.... why dont you guys try a 100% reduction pulley? Just take the damn thing off and stick the belt directly on the shaft

Thats great

my car has 94,000 miles on it
It has had a 17% for about 60.ooo of those and the supercharger blew out last weekend. The car is an 02 so it has the original non coated supercharger on it I now have the 05 sc and it is great. anyway go for it if you are willing to fix it if it breaks, why not but if you arent up for replacing stuff just stick to what is proven to be safe.

 

Luddite makes a very nice Sonoma red Syrah.


curious: what was the symptom of the sc failure?

 

What blew out?

 

I did not pull it apart to look inside the rotors still spun but not at speed. I couldnt get any boost and and the sc made a very high pitched noise while driving. The car ajusted its idle very hight at and above 2k I would assume because of compression. The headers were red hot as if I was driving under alot of load and the exhaust note was very different. I would guess that a bearing was going?

 

...Lodi is an area in Sonoma known for Syrahs, any realtionship to the Luddite name? Syrah, Petite Syrah - in general great wines! Try a Muscato with a dish of Halved turkish figs, marscapone and gargonzola cheese with a drizzle of honey! It'l make the AGS thing a thing of the past.

 

From the dictionary:

Lud.dite

Noun

1. Any of a group of British workers who between 1811 and 1816 rioted and destroyed laborsaving textile machinery in the belief that such machinery would diminish employment.
2. One who opposes technical or technological change.

[After Ned Ludd, an English laborer who was supposed to have destroyed weaving machinery around 1779.]

 

I think jlm is tricksy...luddite red syrah...they're all red...perhaps a vintage created by hands only...never made the connection what with the wine context.

 

I was drinking one of these, very nice:
http://ludditevineyards.com/wine/languid_duck.html

 

I know we're off topic, but thanks for the link jlm. The Arts and Crafts movement - connected to my profession - was also a rebellion against machines. The industrial revolution is certainly responsible for many good things. But some of the incredible handy work of wood, textile, and iron artisans has been lost forever - the same is true with wine. We may never see some of the spectacular wines of yesterday thanks to technology...but we'll never see poor wines either. Mediocrity it seems, appeals to everyone, and, no one...

I owe Spillman another apology for off-topic discussion.

 

minicoop78,

I have to say great attitude! Its people like you that understand that we are all pushing our engines and parts (SC's) to their limits and things happen. I love hearing people who have had things happen like you have, and they don't go blaming everyone else for the problem. You knew the risk, and it was just bad luck something happened.

I have something to add to this 19+4% discusion. I think there are a lot of great points, it surely will produce more boost, but more heat. larger IC definitely needed. SC's redline is say 16,000RPM, and the normal 15% pulley is hitting this at RPMs that exceed stock engine redline. The water pump doesn't have any issues here. This is well proven or Mini wouldn't have put this on the JCW car.

If we work at keeping the SC below its redline, but use the 23% combo it will be perfeclty safe. The benifit is the offset powerband. Will the lower engine redline but higher power make the car faster??? If the area under the HP curve is great yes! To find this out, a dyno run of couse is needed, and also the knowlege of the SC's actual redline would help. We can then figure out what is better, higher engine redline with less overall boost, or a lower engine redline with higher overall boost.

Its kind of like your 9000K RPM honda that makes 220HP vs. a WRX that makes (for argument) 220HP. The honda makes all the power up top and the WRX does it down low and in the midrange. In the end the WRX is faster because of the area under the curve. That lower end power gets the car moving faster soon. I belive the same thing with the 23% combo. But if the engine redline has to be 5000K then maybe not.

When someone talks to Eaton, and finds out the true SC redline, only then will we know what engine redline is need for the 23%.

The 4% pulley we made was never intended for this situation, but if it works great!

Also some of the other failures of SC could have been because they were spinning to the Chipped engine redline with a small SC pulley driving the SC way past redline. Minicoop78, what is your engines redline with the 17%?

 

I think that supercharger redline is already known. In fact here is a post by our boy Ryan that I was able to find...

Here is a rough graph of engine speed versus supercharger speed:


You see that the stock pulley basically spins the blower very slowly versus the M45's 17,200RPM redline. On that note, you'd need to spin the engine to 8,350RPM to redline the blower! However, as you change the pulley, the engine RPM to redline the blower drops significantly.
The JCW pulley - max engine RPM is 7,338.
15% pulley, max engine RPM is 7,260.
17% pulley, max engine RPM is 7,137.
19% pulley, max engine RPM is 7,018.
These numbers represent maximum RPM to not exceed the M45's redline. So you see, with a stock ECU redline of 6950, you can run whatever pulley you want and not exceed the supercharger's redline. Keep in mind that that the more you spin the blower (and the engine) the shorter its' service life in time. This is why you always look for grandma's used car, cuz the engine will not have turned over as many RPM's as Boy-street-racer.

Enjoy!
Ryan


So there you have it 17200. That is of course presuming that we're still talking about the M45.

Chuck

 

71k miles on my S and exactly 60k miles with a pulley also. Most of that mileage with a 19%. Of course I'm aware my supercharger could "blow" any day now. But from what I can tell, my MINI never ran so well. The car still feels better than new. Much better than new.

 

Pretty good explanation of octane numbers...

http://www.answers.com/topic/petrol

http://www.uvi.edu/Physics/SCI3xxWeb...solineFAQ.html

(exerpt from above article)

4.9 What energy is released when gasoline is burned?

It is important to note that the theoretical energy content of gasoline
when burned in air is only related to the hydrogen and carbon contents.
The energy is released when the hydrogen and carbon are oxidised (burnt),
to form water and carbon dioxide. Octane rating is not fundamentally
related to the energy content, and the actual hydrocarbon and oxygenate
components used in the gasoline will determine both the energy release and
the antiknock rating.

 

I don't have the car in front of me at the moment to verify the answer to this question, but if it does not have a serpentine belt, it is at least theoretically possible to have a crank pulley that does oversizing on the band that runs to the supercharger, while having regular or even under-sized bands that run to the accessories. Just a thought... Oh, and if the Mini does use a serpentine belt, anyone ever think of converting it to a multi-belt system? This strikes me as more difficult, but could be worth the effort. :smile:

 

Ryan, could you translate the numbers on the grapgh to % reduction? so I can have a better idea without going crazy trying to figure out what size is what..

 

Based on blower speed, lines on graph from top to bottom:

19% (2.078")
17%
15%
JCW (14.?%)
Stock (2.565")
Note that the pulley size legend on the right is the inverse.

 

thanks, i have a 19% and i was wondering where i was...

 

So would the factory red line be ok for a 23% reduction?

To all of you that helped or tried to help in my decision of 19% with a 4% crank... I have someone found a bit of sense in myself and I am upgrading the fuel management (JCW inj. with GIAC) and the cooling system (either A to A or W to A with NO2 cooling it)

 

I think the graph would say, resoundingly, no: the factory limiter will be too high. The thing is, you'd expect a little more than an equal increase in SC rpm at a given engine rpm in going 15 to 19 as 19 to 23 (4.71% reduction in the first place, 4.94% in the latter place). That would mean the red line with 23% would be around 6650 or so.

Keep in mind- that is the RED LINE. Thermal efficiency occurs before that time. Who knows when it'll stop beneffiting you, rpm-wise, but it would be lower than that point.

It is a good move to try to cool, but be very careful cooling the IC with NOS. It sounds 'cool' but is dangerous because you have trouble, then, controlling how much gets into the intake and then engine (and some will certainly do so!). This caution was better given somewhere else, though I forget where right now...

Good luck either way. Take care.

 

Is the NOS getting into the intake really that big of a deal with the alta intake? It seems to seal fairly well on the hood.

 

spillman,
great info, but what is the crank pulley size being used? I am trying to figure this out. The numbers you have are correct for the SC pulley, but the stock crank pulley diameter isn't mentioned. The stock size is 5.48", if you take a 19% pulley(2.087") this combo runs the SC 2.63 times more than the crank pulley. That puts your 7018 engine speed to 18400 SC RPM. not 17200. If i figure out your crank size going backwards, the crank size is around 5.1ish?? The measurement numbers are rounded they are not the exact size, before anyone asks.

 

7500 redline. From what I understand the eaton is rated to 100k and my car has 94+k but with a 17% the sc is further along. I knew it was going to happen sometime so no big deal, its an easy fix.

 

I'm confused... I have the stock crank pulley. Where did you get the idea it was not? That graph isn't mine and neither is any of the info on redline. I just qouted someone who posted it.

 

spillman,
I know you have the stock part, i was just relating to the graph. The stock Crank pulley size and the SC size play into the speed at which the SC spins. With the calculations on the graph (now i noticed it wasn't yours, sorry wasn't paying attention) the numbers don't add up. The crank pulleys the graphs are using are somewhere in the 5.1 size range

Here is what i came up with for CRANKpulley/SCpulley ratios, all at 7000RPM

15% 2.511 Ratio and SC RPM of 17600
17% 2.57 Ratio and SC RPM of 18000
19% 2.63 Ratio and SC RPM of 18400
23% 2.77 Ratio and SC RPM of 19400
Meaning the SC spins roughly (ratio number) times more than the crank pulley.

Hmm, maybe people have been spinning the SC faster than we all thought??

By my calculations, the 23% pulley can only go to 6200RPM before it passes the redline of the SC. So lets say you can push it a little to 6500. Surley it will make more HP and boost below 6200 than any of the other pulleys, but what really matters is the area under the curve. This is what will show that this combo will be faster. With the 23% you will have more HP but in less time(time being RPM). Where as a 15% pulley you will have less power but over a long time. When racing down the drag strip the car with more area under the HP and torque curve will win.

Next is how to control the redline. MDS makes a DIS 2 which can control redline, this would be a great option. The is something that really needs a test car. A dyno run of the 19% pulley,(tuned of course) then a run with the 23% combo (tuned of course) will tell us which car will win!

Now on the street this would be a great car, lots of low end power. Man that traction control will be working its butt off trying to keep the wheels from spinning! I do have a few 4% pulleys to try if anyone is interested!

 

ALTA2, so now you are making me think about my 19% pulley... if the redline of the SC is 17200rpm... then even the 15% pulley will puch the SC way pass the redline.

now i am no expexrt but wow this mean my 19% pulley is basicly kicking my SC butt...

i have MTH and Franz has lower my redline to about 6900rpm a bit lower than stock...

are you sure this numbers are right?