Anybody burn out their supercharger from running an aftermarket pulley?

 

I've never heard of anyone "burning out" their SC by using a reduction pulley. The pulley just speeds up the SC and the only time you might have a concern would be if you run your MINI at 6500RPM all the time, in other words, fagedaboudid!

 

I make scrambled eggs with mine

 

Way, way, back a long time ago there was this fellow who had a supercharger failure or so they say. Now this guy, famous as he can be, was a motoring and driving hard. They say he had a 19%er on there and it was of an earlier vintage it that it went on the way stockers do. Shrink fit that is, where ya heatem up and slipem on and transfer all that heat to the shaft. And as they shrink, theys tighten up so's no slipem they be. Well as it were they was a lot of talk and was to be a little investigation on what to be the cause of this or so he said. Could it be that the heat he was a usin had caused the shaft bearing seals to go, lettin out all his lubrication and causin his supercharger to blow. But though we been a watchin no report thus far been seen as to the cause of failure of that mans motoring machine.:smile:

 

We at Mini Madness advise against using a 19% pulley for a track car. We've had 2 of our sponsored racers blow up their superchargers so far. Hell, the Rasmussen Mini race car threw theirs about a month ago using the 19%. For street use though, it's obviously fine, or we wouldn't make and sell them

 

Care to elaborate on what "blow up" means, and how you were able to correlate said "blow up" with the pulley ratio?

 

Yes, exactly what was the point of failure, please be as specific as you can.
:smile:

 

when you say track car do you mean a dedicated track car or even occasional track use ? I get out on th etrack a few times a year and run the car HARD wil 19% pose a problem?

 

Folks. I'm not saying the presence of the new pulley messes anything up but.....the supercharger simply engages more often and for longer periods of time resulting in a change in the long-term failure rate...or maybe not.

 

ANything that rotates over 19k rpm is bound to break.

 

Actually, the 'engagement' of the SC (aka closing the bypass valve) is completely dependent on engine vacuum (i.e. stomping on it) which is completely independent of pulley size. One can use a light application of throttle and get to redline without ever engaging the SC. I can't see anyone doing this as a practical matter, but it's true FWIW.

The smaller the pulley, the faster the SC spins, whether the bypass valve is open or not. Arguably more stress is put on the SC when producing boost (bypass valve closed) and at higher revolutions.

 

I think he means that the cars are dedicated track cars, but note, I think they run well over 6950 rpm. Is that correct Matt?

 

Yes, it MIGHT

 

Turbo's spin at well over 100k RPM all day long and have no trouble.

Famous word: "but". FYI, there is no clutch on the supercharger. With an overdrive pulley, it just spins faster per the engine RPM. None of this "longer periods of time" stuff

OR

You mean to say that just having an aftermarket pulley sitting nearby my car will cause the blower to fail?!

 

Turbines dont count. THats like comparing a Jet engine to a propeller.

 

But your statement was blanket that if it spins that fast it has to break. There are a ton of cars out there right now running 19% and more. So far so good because nobody is posting how the sc failed even with some running 21%. Not to say there wont be some in the future.

Turbos and sc's are definitly not an apples to apples comparison but you did say

 

I have heard from a VERY reliable chipmaker that there are people in Mexico running pulley's with a 24%, YES 24% reduction and have logged over 25K on them with NO problems...

 

yep you're right. But then I said Turbos dont count.

 

And there are people with V-8 vegas and 914s using stock transmissions that have held up for all these years. It depends how they are driven.

 

obviously you dont see the point.

 

oh? how so? Is your point not to be more specific?

 

Well, I've never heard anything bad at all about 15% pulleys. Apparently, there are some dealers who'll install them.

Having said that, I think it would be kinda cool in a purile sort of way to blow up my supercharger. At least I know I've been driving it right! Actually, was it not Ferdinand Porsche his own self what said that the perfect race car wins a race and falls a part just after passing the finish line?

 

yes mine failed at 94k with 17% for ever it takes alot though i beat the !!!! out of my car and not the piston rings are going

anyway i wouldnt worry about it it went out overnight not a gradual thing

 

minicoop - can you clarify 'failed'? What failed? Bearings? seals? Lobe 'growth' damaging the case?


FWIW Dreams - the JCW kit installs a 15% on an essentially stock SC (supposedly with coated rotors), so MINI de-facto says it's safe. Throw out the stock rev limiter, however, and all bets are off.

 

This is only semi related but there was a 19% in the mix. About 6 weeks ago a mini went into a local dealership for trouble shooting. They found the number one cylinder had damaged rings. They successfully denied the warranty claim as the owner had a 19% pulley on the car . The owner tried to take the posistion that JCW cars had pullys but BMW came back with the argument that they were less than a 15% reduction . Lesson to anyone using a 19% would be to remove it if you are taking the car in for a power train issue.

Randy
M7 Tuning