Hello,
I am one of the ones interested in pulling every ounce of power out of the mini engine. However, i also put weight in longevity. Some may scoff at me saying i am attempting to build a hypocritical engine, or its an oxymoron. I disagree. I know there is a happy medium. The general modification consensus with pulleys seems to be the 15%. from what i understand this will last the lifetime of the car as long as the car is cared for.

what is the expected life expectancy of the charger and motor with a 17% pulley? this is for a daily driver that might get raced two-three times a year at a drag strip. Never autocrossed, and not often street raced.

from what i've heard i won't even consider a 19% pulley unless someone can prove me wrong.

any thoughts or inputs regarding the 17%? what are its horsepower gains compared to the 15%? (i want to see if its even worth it as well.)

Thanks for your help.

-ABT-

 

I have had 0 problems witha 19% for over 20000 miles, but to be competly honest there is no way to tell if a 15%, 17% or 19% will or will not shorten the life of the engine, time will only tell that, sure things can be tested, but long term effects are very difficult to test, and a long life engine failure it is very hard to pinpoint the blame, it can be a pulley changed out or as simple as a material flaw or weakness, only over time will we see this answer, if a large percentage of engines fail at 100000 miles with a 19% pulley and a large percentage of the untouched engines fail at 150000 only then can you make the assumption of the 19% shortening the engine life by 50000 miles, nut then again where do you fit in those percentages.... I have seen brand new untouched engines fail in under 20000 miles, it happens you just hope not to you, Good luck on your quest for this answer, I personally feel there are to many variables at play, to judge one pulley over another in long term affects only true time will tells us that....just my two cents, I do agree there is a shorting affect by more stress added to the engine, but really can we measure how much and how much shorter life it will make, i dont think so, driving styles, maintinence, enviroment(extreme hot or cold and dust levels, etc),and so many other variables......we will see over the next couple of years.....

 

I'd love to know what you "heard" about the 19%. I highly doubt it was good information. And if you're really that much against the 19%, how can you seriously consider the 17%? They are so close - do you think one will destroy the engine and the other will have the longevity of stock????? Just curious...

 

the ONLY thing i've heard about the 19% (and i don't get out much, so i'm no expert by any means), is Randy's story when he installed the 19% on his cooper and had a supercharger seizure before he got out of the state on his trip to a pulley party.

i know this is not representative of all 19% pulleys, so thats why i said "someone prove me wrong." case in point: caddman did just that.

i would love to hear more success stories from the 19%. i am not looking so much for year or mileage answers as much as exactly WHAT stress the difference causes on the engine. (i.e. what are the chances that Randy's seizure was an isolated incident or a symbol of what happens with a 19% on a modded engine)?

in other words, is it "ok" to have the 19% as long as you have something else (i.e. do you NEED a larger air to air? do you NEED the air to water?)

thanks...

-ABT-

 

I'll take a spin on this topic: I would tend to only recommend taper-bore pulleys, as they do not have the risk of damaging the supercharger shaft seal during installation like interference-fit pulleys. This does not mean an interference-fit is destined to cause o-ring failure, just that it's more likely.

That being said; Eaton recommends changing the M45 every 100k miles. I can't say if that is from a lubrication POV, or a total revolutions duty cycle POV. Furthermore, this 100k mark is most likely accounting for 90th percentile driving; those that strictly race their MINI's obviously can't expect that kind of lifespan from the blower. In that context, you can derive for yourself how long the M45 will last before it either generally fails or the Ql get's unreasonably high.

$0.02

 

>>I'll take a spin on this topic: I would tend to only recommend taper-bore pulleys, as they do not have the risk of damaging the supercharger shaft seal during installation like interference-fit pulleys. This does not mean an interference-fit is destined to cause o-ring failure, just that it's more likely.
>>
>>That being said; Eaton recommends changing the M45 every 100k miles. I can't say if that is from a lubrication POV, or a total revolutions duty cycle POV. Furthermore, this 100k mark is most likely accounting for 90th percentile driving; those that strictly race their MINI's obviously can't expect that kind of lifespan from the blower. In that context, you can derive for yourself how long the M45 will last before it either generally fails or the Ql get's unreasonably high.
>>
>>$0.02


thanks ryan.
unfortunately thats all kinda jargonistic to me, as i have no technical prowess. Can you translate what that means to my scenario? In other words you are saying as long as i don't race regularly, that it won't do any major difference than a 15%? i am not familiar with what is a taper-bore pulley and what is an interference pulley.

thanks
-ABT-

 

I also have the 19% and have had zero problems. I drive it every day, I love to sift at the redline and have autocrossed it before. Zero problems.

RaceCarDriver

 

All else being equal; failure of the supercharger will occur first with the 19%, followed by, in order, the 17%, 15%, JCW, and stock. Whether the delta in failure between pulley ratios is significant or not, I cannot say.

Taper bore is a multi-piece clamp style that tightens around the supercharger shaft. Interference fit is a one piece hub, friction fit. Neither will slip on even the most aggressively modded MCS.

 

Thanx Rye, that sounds great. I take that as very exiting news, one day my eaton will be saying nite nite and I'll be able to buy a cool new sc that has been made to directly replace the by then low tech ehr blown one? Sweet!

 

Supercharger Life = L
% Reduction = P
Amount of time flooring the throttle = T
Warranty worry level = W
Miles driven per day = M

L = (2/W) * (T^P)*M

j/k

The real answer is, nobody knows. But, the only reported failure so far seems to be from Randy, who admits there were several factors at work in the failure so he can't pin it on anything specific.

 

lol like no oil in the supercharger.....he reported that there was no oil, but did not know why some type of seal failure, but that could have been to all the pulley swapping(testing) or the "heat" transmitted by the interfenece fitted pulleys damaging it, but who knows............

 

You've answered your own question. If you don't believe that a % pulley is prudent, you shouldn't do it. As to the 19% failure, Randy's is the only one that has been published, and his explanation [do a search] admitts that the pulley was not to blame.
Frankly, all manufacturers error on the side of caution. If you look at the development life of any engine, you will see the same basic unit developed for ever more power and torque through it's production life. Take the original Chevy small block. Can they be blown up? Yes, but the basic design evolved to where it's specific power exceeded the original's by a substantial margin.
Based on the many tuners out there who have adopted a pulley as a necessary step to improving the power output [including the factory's JC Works], why wouldn't you 'pulley up' ?
Has anybody out there blown one of these motors up? Pulley or no pulley?
Speak up!

 

i have only "heard" of two blown mini's but im sure there is more, but one of the two was due to waterlock by submergine it, and the other was due to NO oil, neither of these two you can blame the sc, i also would like to hear more on blown mini's and why, has someone overblown their motor and if so what PSI where they runing, and how turbo, different sc, also how many superchargers have failed and why? Please those whom had blown motors speak up!!!!I wanna know why!!!!

 

so based on this discussion i would say its safe to go with the 19% then huh?

the reason i asked in the first place is b/c it seems EVERYONE has the 15, you never hear of anyone offering the 19... on top of that almost every vendor's "stage kits" offer packages including a 15 pulley. thats why i was confused - almost no mention of the 19 is ever made.

 

I think the reason you haven't herard as much about the 19% is it is realitively new as a saleable product, and not as widely available. I think you will see more offered as time goes on. Like I stated above, where are the blown motors. With 19% product being marketed now, its a good bet that there are some 21% pulleys running around out there. I would expect tuners would blow up motors as a normal expense of development.
There is the old adage that the chain is only as strong as the weakest link, and this is certainly true. Where are the blown motors, the failed water-pumps, the blown head gaskets, bent valves...anybody?!
I do think you can pay a price for being an 'early adopter', but I don't think any of the tuners are out there looking for unhappy customers. I think that they have all pretty much determined that there is an improvement to be made by changing out the pulley, so thats a given. Your question is valid, where is the limit? The only real answer is where and how do they fail?
I say: show me the bodies.

 

>>I say: show me the bodies. >>

i am with ya