First off, sorry to Mark for letting my emotions get ahead of me in this discussion:

https://www.northamericanmotoring.co...c=18831&81

I haven't edited any of my comments, so they're all there to see.

Anwyay, lately there has been quite a bit of interest in the use of pulleys smaller than the accepted 15% ones. I'd like to post some graphs and data and see what people think of these concepts.

I haven't tried a 17% or 19% pulley myself, but plan to soon, with extensive data logging and hopefully dyno testing.

Here are Eaton's charts for the M45 supercharger . I realize that our supercharger isn't exactly an M45, but it's pretty close:

Here's some information I have found here and elsewhere. I figured it should all be in one place. Please let me know about any inaccuracies and I'll fix them. Likewise, help me fill in the blanks.

MCS Powertrain Article (in English, no pics): idisk.mac.com/thezachs/Public/MCS_Powertrain.pdf

MCS Powertrain Article (in German):
www.apqv05.dsl.pipex.com/m07-02-08.pdf

Presumably, the supercharger is an Eaton M45:
www.automotive.eaton.com/product/engine_controls/M45.html

The supercharger is a Roots-type blower, manufactured by Eaton to BMW's specifications (notably, the water pump is driven off the back of the charger). It turns 2.06 times engine speed, which works out to 14317 rpm at the 6950 rpm rev limiter.

Here are some charts from the Eaton page linked above:





This blurry pic from MINI's own technical literature shows the compressor efficiency map:



These show plots of both the stock and 15% pulleys on otherwise stock MCS:

 

Thank you andy for posting this thread, because this is what my thread turned into, and was not what it was supposed to be.....

 

Also a quick question, why did you use 2nd gear, why not fourth since it is closses to one to one as well closest to peak loads?

 

"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."

Quote from Ryephile on webbmotorsports forum



thought this should be inclued since this is a technical discussion....[img]null[/img]

 

This is a topic I hope sees a lot of testing and wringing out, because my next mods are going to be a CAI and pulley. What I am beginning to see is that the 17 and 19% pulleys seem to make better numbers at the higher end than many have predicted, especially with better intercooling, but there is not enough real-world longevity data yet. It seems to me that given the current numbers coming out of the 17-19 camp, their pulley would suit someone (like me) looking for more lower-end grunt rather than high winding power, especially if the rev limiter is not raised. There is a point of diminished returns on the top end, but this is generally the case with any 'overclocked' SC. What surprises me is that the returns dont seem to diminish as much as I would think.

The big question for me now is how long the overall setup is going to last in a day-to-day driving situation coupled with some occasional track time and 'spirited driving'. Will I need to stock up on waterpumps and belts and have a source handy for replacement superchargers? It still seems that the trans and engine bottom-end is holding up well in most cases, no reports of blown trannies and windowed blocks have surfaced yet for the most part. Howbout the head gasket? And most of all, what is gonna be the best 'overall package' of parts needed to make the most of the overdrive pulleys, aside from what's obviously needed?

My eyebrows have been raised, now I am wanting to open my wallet.

 

Now that you have posted graphs i would like to comment that notice in your eaton m45 graph on hp the gains are not linear from 5Psi to 10psi...

Great bear i have run my 19% for over 15000 miles in the same fashion you are looking for with no problems, none of the problems you have discussed, if you take note to the first link any posted it to was my 19% pulley group buy, but turned rather into a converted to this type of discussion, as fart as your parts needed, is just the pulley nothing else required, but if you plan to do alot of spirited i would look into an intercooler, there again for most not required....

 

>>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."
>>

From Eaton's website: "With helical rotors and an axial inlet the Eaton supercharger can be spun to up to 14,000 rpm, thereby reducing package size. " This is also reflected in the graphs posted by andy.

--
Cheese

 

macncheese i was quoting someone to show just that, was not my original post, just trying to show it in simple terms to help clarify some may find Andy's graph a little confuseing.....

also just to put in an another thread of same topic



more pulley power

 

>>macncheese i was quoting someone to show just that, was not my original post, just trying to show it in simple terms to help clarify some may find Andy's graph a little confuseing.....

So the 17,200rpms is heresay?


--
Cheese

 

No you are misunderstanding as usual, the graph by ryephile is showing the comparison of supercharger speed vs engine speed due to different pulleys, Andy's graph is showing his with or without 15% pulley.....

the 17,200 is eaton's recommended redline for the supercharger, not in question here or in any thread of this type.....

Maybe i missed you arguing point? I dont think I did......

not sure where the 14,000 came from your are using except for the possiblilty of what the supercharger is spinning on a stock MCS?

 

>>not sure where the 14,000 came from your are using

If you LOOK at the graphs is this thread, you see that they go
up to 14,000 RPM, NOT 17,200 RPM, so the question is:

Where is a reference showing the Eaton suercharger
redline at 17,200 RPM?

Please post the link.

Here, I'll post one showing 14,000 RPM: Eaton M45 graphs.

 

>>No you are misunderstanding as usual, the graph by ryephile is showing the comparison of supercharger speed vs engine speed due to different pulleys, Andy's graph is showing his with or without 15% pulley.....
>>
>>the 17,200 is eaton's recommended redline for the supercharger, not in question here or in any thread of this type.....
>>
>>Maybe i missed you arguing point? I dont think I did......
>>
>>not sure where the 14,000 came from your are using except for the possiblilty of what the supercharger is spinning on a stock MCS?
>>
>>

I guess you missed my arguing point.
Eaton's recommended redline is 14,000 rpms as stated in my quote. You can view the page for yourself at:

http://automotive.eaton.com/product/...rchargers.html

The fact you're looking for is in statement #3. So maybe its never been in question to you before but is now. If you look at any of eaton's graphs (which andy posted), they all end at 14,000 rpms.

 

Farts? Let's try to keep this thread on topic!

 

greatgro, oops on the typo.. lol was supposed to be parts.. my bad...

 

Because the graph ends at 14,000 rpm it must be its redline right, so if my speedometer in my GTA stops at 85 it must be only capable of doing 85 right, nevermind that im pushing 1300 hp and 900ftlbs, right....

my 17,200 redline for the supercharger came directly from conversations with eaton the phone, as well as thier division located here in town.....

Randy qoute as well..

"Actually, redline for the supercharger is at 17,400 RPM, so that is the limiting factor. The 15% pulley brings the RPM limit at redline to 16,900, so there is still a relatively docile buffer".....



quickie on the pulley

I could keep going if you need me to, but the most important is that i spoke to eaton directly, so has Randy, and BMP, etc I have aslo spoke to those other vendors with the same numbers from eaton, so not just one slip of the tongue from eaton...

the graphs they use stop a 14,000 due to that is what they sell them to the car manufacturers at also per eaton phone conversation....

 

I also went to your reference and it reads ". With helical rotors and an axial inlet the Eaton supercharger can be spun to up to 14,000 rpm, thereby reducing package size. " Nothing is said adout a redline or rev-limit on the page you mention. If you follow Eatons sugestion for a rebuilt SC and go to Magnuson products

http://www.magnusonproducts.com/mp45.htm

their graghs go to 16,000 RPM but they still do not mention a redline for the product. I realize this is not the exact pump on the MINI but it is close. Why would you believe a redline exist simply because a graph stops, or because it can be spun to some RPM It will also spin up to 1000 or 3535 or some other arbitrary number that is NOT stated as a redline? Magnuson's 16000 is closer to 17200 than your graphs 14000. BUt the 16000 is a published number, not redline, for the MP45. As the graphs are showing no signs of degredation at 16000 it seam they just might be good for another 1200 RPM. If at this point if anyone still wishes to be upset by 1200 RPM you have already missed the boat.

Motor on and smile.

 

For crying out loud, stop with the bickering. Present your numbers and evidence why it will not blow your daily driver apart and leave it at that. We dont need to rehash all this theory and redline mess, numbers are numbers, and if those are the numbers he has then so be it, if someone else has some relevant numbers then post them, I'm friggin tired of all this BS arguing and name calling, and that's what it is, from all sides!

 

The above picture is a set of eaton rotors that have expanded enough from the heat of being overworked by a smaller pulley that the ceramic coating literally pops off and seperates itself from the rotors. The rotors then machine themselves to fit the case.

There is only one place for this scrap to go, so now the question is: How does epoxy and aluminum chips figure into the air/fuel ratio?


--
Cheese

 

Now that we've calmed down, maybe someone can explain the merits of each pulley as it pertains to the car and driving styles. I understand the smaller the pulley the more boost gained. I also understand you really want to set up a daily driver a bit different than an out and out race car.

Anyone know the hp numbers for the various pulleys at a given rpm?

>>>The 15% pulley brings the RPM limit at redline to 16,900, so there is still a relatively docile buffer".....<< What's the numbers for the 17% and 19% pulleys given the same circumstance?

 

This was a comment from Super_MINI in the ill-fated previous thread

"Is it possible that we are getting so much more HP from the 19% pulley because we are adding some additional oxygen with the added boost but generating much more HP because or a leaning out of an otherwise rich mixture? We know that the 15% pulley generates around 15hp over stock and that we can get an additonal 15-17hp out of a good aftermarket ECU that leans the mixture to generate higher HP numbers so is this why we are seeing such a huge difference with the 4% smaller pulley with the stock ECU between the two dyno runs? Have we passed over the rich mixture on the way from 15% to 19% thus resulting in the equivalent of a leaner ECU upgrade?"

I think that this is a good point and I was wondering what the experts might say.

To break it down into one sentence, is the 19% pulley and stock ECU roughly equivalent to 15% pulley and kick-a$$ ECU?

Correlary to that point: if the above is true then I would imagine that a remap for the 19% pulley would probably yield minimal gains since the engine would already be running closer to the ideal fuel/air ratio.

Thoughts?

Chuck

 

As I have said before, I've never seen ANY group of people talk and theorize about what does what than these MINI forums. Everyone says so and so intake is the best because of the Law of What I Just Made up. We all talk and talk and talk and talk about how there is no way a MINI can handle X HP and X TQ because thats just what everyone says. By no means am I saying these forums are a waste of time, but certain people nitpick the smallest details that it's bordering pathetic. There are a ton of people here who talk like they know everything there is to know about everything.

Tom

 

>>As I have said before, I've never seen ANY group of people talk and theorize about what does what than these MINI forums.

Tom,

Sometimes, someone or other, usually a seller of MINI merchandise, makes
a claim about their product that's a bit "out there", and some of the more scientific
thinking members of the board call them on it using actual science.

Then, they justify their claims using waffly theories, and it turns into a dustup.

Some of us like to know what we are buying, and like to help other MINI
folks not get ripped off by snake-oil salesmen.

And some of us actually LIKE to see the numbers and graphs. I really enjoy it.

If you don't like it, and are not getting the information you want, PLEASE post
a message asking your question instead of complaining about the thread.

We'd all be happy to have the distraction of another member's question.

Ask-on dude!

 

Thanks Trippy - Hopefully I don't sound like a jackass when I say, that was probobly the only "nice" post I've seen from you.

I'm pretty sure I understand what the graphs are explaining, but they can vary (in cases, depending on what you are measureing), am I wrong? Obviously, it gives me a good idea, but what do I do with said info? I think a lot of it has to do with affirming your position as someone who "knows a lot." Maybe I'm wrong, but that's sometimes the feeling I get when I have an opportunity to post information that really means nothing to your audience.

Tom

 

>>This was a comment from Super_MINI in the ill-fated previous thread
>>
>>"Is it possible that we are getting so much more HP from the 19% pulley because we are adding some additional oxygen with the added boost but generating much more HP because or a leaning out of an otherwise rich mixture?

Well I always thought that even when you put any pulley smaller than stock, the air fuel mixture should be unaffected as far as the side of the engine that manages the fuel delivery is sufficient in relation to the extra air that the supercharger is able to cram into the car. I don't have any data or quotes to prove this but it seems to make sense because regardless of how powerfully the SC is running, the engine management always strives to achieve the same ratio. If somewhere along the fuel delivery system there was a capacity problem, then the ratio goes off no matter what, but I don't believe that is really a problem since the JCW cars run more powerfully yet the fuel delivery is the same. With that kind-of stuff said.. if you are running a 19% pulley with an a/f ratio equivalent to stock (rich), then the ECU gains may, even moreso, produce a significant change in engine efficiency. Time for some kebab, lol.

 

>>Hopefully I don't sound like a jackass when I say, that was probobly the only "nice" post I've seen from you.

If you want to have "Sounding like a jackass" as the major part of your
personality Tom, you have a thing or two to learn.

Literally.