Anyone use this or seen this "Light Weight Crank Pulley" on eBay??

Link .....Crank Pulley on eBay

 

Hmmmm...interesting. Would the underdrive also increase the revs of the 15% pully making my Mini blow up? Seriously

Like to know more.
Sid

 

Two Words... Harmonic Balencing

The origional Crank pulley has this, if you just add one with out that, you will get some nasty vibrations. Also, The underdrive will reduce the effect of the Supercharger.

Basically, for the S, it would not help at all, for the cooper, you would have too many issues that it would also not be worth it

Thanks
Dan
Pilo Racing

 

That's what I call a boonch-o-crap. There is no way a lightened crank pulley would produce 2.7 hp, the harmonic balancer notwithstanding.

"The rest of the gains are from underdriving, which accounts for about 15% of the total gains. We do not push underdriving for two main reasons. Our main reason is to keep charging systems, air conditioning, power steering, and water pumps moving fast enough for every day driving."

Huh?

 

I would not risk this pulley on a MCS. The seller might go out of business.
Notice three bolts compared to the st`�ž„pulley-count the bolts.

 

>>Hmmmm...interesting. Would the underdrive also increase the revs of the 15% pully making my Mini blow up? Seriously

No, it would underdrive it, or turn it slower. Negating some of the benefits of the 15% pulley in the first place.

Fifty years ago, when generators were used on cars, the armatures on them would tend to fly apart from centrifugal force during sustained high-speed racing. The solution would be to decrease the diameter of the crankshaft pulley, which would turn the engine accessories slower at a given RPM than the standard pulley. Presto! No more exploded generators.

Underdrive pulleys continued to have some benefits when engines used to drive massive steel cooling fans off the water pump pulley. It took less power to turn the fan at a slower speed, and at cruising speeds the difference in fan RPM was inconsequential.

On the MINI, that pulley is a pretty engine dress-up item, and nothing more. The power steering is electrohyrdaulic, so that's not a belt-driven load on the engine. The A/C compressor freewheels until the compressor's clutch is engaged, so that's not a load on the engine. The only things left are the alternator, water pump and, on the S, the supercharger.

You don't want to turn the water pump slower at idle. It's designed to maintain a certain flow rate at idle. You start messing with the pump's impeller speed, and it may not be able to move enough coolant for the cooling system to work effectively.

You don't want to turn the alternator slower. It's designed to have a certain output at idle to meet the electrical demand of the MINI. It also draws air through itself via two internal fans, which keep the alternator cool. When it's being driven slower, and asked to produce the same amount of output, the alternator WILL run hotter, which shortens its lifespan.

Of course, after buying a 15% pulley for the supercharger, who wants to drive it slower?
_________________

 

Guess that answers that question. Thanks guys.

 

Uh, what Parklife said.

Geez, could you have some extra knowledge about underdrive pulleys?

Nicely done!

My father has one on his car and swears by it.

 

what abnout just a lighter pully? like a lighter flywheel? my brother has a 04 WRX and he put a lighter pully on his crank and it revs so fast its silly. mabey a cheeper alternative to lighter flywheel? duno just a thought.

 

>>what abnout just a lighter pully? like a lighter flywheel? my brother has a 04 WRX and he put a lighter pully on his crank and it revs so fast its silly. mabey a cheeper alternative to lighter flywheel? duno just a thought.

The WRX has a boxer engine which is harmonically balanced by design, so it's safe to use a lightened pulley on one.

 

ok what about ours? is the balencer attached to the pully or is it seperate.?

 

Just like the Unorthodox racing underdrive lightweight crank pulleys sold on ebay.com-

I see Minimania has a light weight crank pulley in polished and black finishes
http://new.minimania.com/web/SUBTYPE..._Inventory.cfm
Performance gains through reduction of rotational mass in the engine is a tried and true concept. This lightened crank pulley for the MINI Cooper S is CNS-machined from premium 6061-T6 aluminum billet, and maintains the stock diameter while losing about 75% of the stock weight. The reduced rotational weight has shown increases in horsepower and torque across the entire RPM range (maximum gains @ 4000 rpm).
Note: Special Pricing applies to orders placed on the web only.
NME5030 Categories: [ENGINE] [ENGINE-TRANS_NM] [DRIVETRAIN_NM] [ENGINE_NM]
Internet Only Special Until Jun-18-04 for: $219.95


NME5030/BLK Categories: [ENGINE-TRANS_NM] [DRIVETRAIN_NM] [ENGINE_NM]
Internet Only Special Until Jun-18-04 for: $219.95


If it is not safe why would minimania carry the product?
_________________
MINIlani home of Jasmine Trias

 

It says max gains at 4k RPM (and accross the range), yet no numbers? I'm not totally sold on such weight reduction as a huge factor. Losing 75% on a free spinning mass such as wheel/tire is much impacting than a belt-driven mass. At least that is the knowledge I got when inquiring about SC pullies and their relative masses...

I'd want to know what is the weight delta, power (hp & torque) gained, and cost to install as this is bound not to be a typical DIYer. Only with that information would I then ponder this one. Gotta do the cost/benefit analysis!

 

It is curious that Alta has one out now...



[size=4]Alta lightened crankshaft bottom pulley[/size][size=1]AMP-ENG-500[/size]
[size=2]Original weighs 3.2kg, this lightened bottom pulley is only 417grams![/size]
£102.13 [size=1](ex VAT)[/size]


From MINISpeed.com

 

i never seen this on alta's website though... are you sure it ain't some pretender trying to make an alta product?

if it is such a good product alot of the mini owners here on nam would probably would've done it.. yet not a single source has reported long term effects; perhaps someone like randy or m7 can enlighten us on this subject than anyone else can

 

The problem I see with this and similar solid pulleys over time is undue wear on the supercharger due to unsupressed harmonics 'rattling' the rotors and gears. Granted, at higher speeds the belt does a decent job of absorbing these, but at idle and low rpms there can be some harmonics that would set in and bang the hell out of the SC. The dampened pulley that comes stock was designed to counter the vibrations/harmonics that were found during the engine design and testing.

Now, in the case of a race-only MCS, all bets are off!

These pulleys can be used on the MC engine without the SC issues and might be more beneficial there. The MCS engine will always have 'flywheel issues' from the rotating mass of the SC, with the 17% and higher pulleys exacerbating the problem.

 

I WANTED TO CLAIRFY:

THE ALTA IS NOT AN UNDERDRIVE PULLEY. it is a lighter version of the same diameter. thus all the problems discussed are erronious and were started with the inaccurate statement of it being an underdrive pulley, incorrectly meaning that it has a smaller diameter. Hopefully this will help anyone who searches and finds this post.

 

please check out information like this, as i did, by calling specialists. I picked up the phone and called Adam at Alta, Unorthodox Racing, Randy Webb, George from MINI-madness, and various others who know what they are talking about. To be honest many people on the forums know far less than they thing they know, and I am sure many of you already know this. The forums should have some sort of disclaimer.

 

So, in Lamens terms, this Alta drive is a go, without fears???
i.e. no probs using a lighweight crank pulley???

 

Yes, somebody has to have this. Any thoughts?

 

my understanding is that the in-line four requires a harmonic balancer. lose that function and expect main bearing wear, front seal issues and crank stress.

 

so far ive only hear talk, but no expert like randy, m7, rspeed has ever said anything about this.... those guys should be more informed about a crank pulley as they should be the ones that have taken the mini motor to its max

several key things is that if it's that reliable, randy would've pushed the product, promini should've had it on their silver turbo S, mania should've put it in their stage kits, so why has no one even touched a part like that?

 

I think that was understood prior to your post, but thanks for your clarification anyway. The lack of harmonic balancing is the concern here. And, by the way, some people do know more than you thing they know.

 

Is this covered under MiniMania's warranty.


Again, a lot of people are stating harmonic balancer problems, but do we know this is the case for this car? Mini Mania has been running this a while with no problems.

These initial comments are sounding like the same negative comments we heard in 2002 when the reduction pulleys starting coming out and everyone said that it would cause cavitation with the water pump. People were dead set on that thinking, but it didn't pan out. Is the harmonic balancer the same issue?

 

You are dead right about the harmonic balancing issues.... M7 said the same thing..... preach on brother