And the accessories spinning 4% faster? The a/c and alternator are in the group, I assume? I don't understand the details of MINI's electronics, but would they be calibrated to a particular output from the alternator?

dan

 

That is another question I have as well. I am interested in getting the 4% pulley, but am concerned about the other accessories spinning at a higher speed when at redline. I am thinking I should take a safer step and just get a 2%, but of course, the 4% is the same money, so why wouldn't I get it since i have no supercharger pulley on the car (though I may consider a 15% Alta pulley in the future).

 

Alta is working on an underdrive alternator pulley as they have indicated. I don't recall seeing an anticipated delivere date. AC is another issue. Eurosporthighperformance.com in UT has an underdrive alternator pulley currently. Price is $59 and it is chem coated aluminum. It underdrives more than the 4% overdrive crank you say you are considering. Probably around -15%. I have read tests that at an idle with a stock crank no undercharging was reported even with a full accessory load.

 

Well, with that information, I might as well just get the lightweight crank pulley. I don't see the reason to have to spend an additional $150 or so on each of the other pulleys. The alternator pulley is going to be a PITA to remove. I've never removed a a/c pulley, and I don't think you can with the built in clutch....

Maybe i'll just go along with a lightweight crank and a 17% supercharger pulley....

 

who makes the crank pulley w/ balancer??

 

pilo wanted to make one, but it's not out yet

 

Total brain-fart. Tell me if I'm wrong here. Going to a 4% pulley on the crank wouldn't hurt the accessories one bit. They spin at various speeds as the engine revs in normal driving anyhow, right? And, unless you are hell-bent on redlining at every opportunity, they would not "redline" themselves to the point of failure.

If that's correct, then we don't have to mess with accessory pulleys at all.

dan

 

Good point. Its only 4% right? Its not like your're doubling the rpms at the alternator or compressor. I think some folks that want their cake and eat it too, are the wet blanket on this one. Its an accessory for crying out loud with a limited service life(like the engine!). "I want my car to last as if it were never modified, but want the additional performance." Sheesh!!! If you want it to last, leave it in the garage.

 

Lol. I was thinking about it some more as well. If the engine is spinning at 6600 rpm and now you have a 4% crank pulley spinning the accessories 4% faster, they will only be spinning at 6864 rpm, which should be completely fine. I think i have read here that plenty of people have their rev limiter removed and track thier Mini's with a new 7000 rpm rev limit with no problems. If that is the case, I think I am pretty satisfied that it will be ok. The only thing I am thinking is that I might want to throw a 15% pulley on there later. Not too sure about putting 19% over-rev on the supercharger. Maybe i'll go with a 2% and a 15% so I get a 17% overall. I know, i know, people have done the 19%, but in my mind it just worries me. It isn't like 2% is really that much. I guess I'll see what comes out of this from some more searching around on the site. I'll probably end up with a 19% overall at some point!!!