For me to make an accurate detemination about pulley installs on MINIs does anyone know if the harmonic balancer or vibration dampner needs to be modified or removed?

 

>>For me to make an accurate detemination about pulley installs on MINIs does anyone know if the harmonic balancer or vibration dampner needs to be modified or removed?

The harmonic balancer is usualy located on one end of the crankshaft. There is no need to remove, modify or alter this part to install a reduction pulley of the supercharger.

Cheers

 

>>The harmonic balancer is usualy located on one end of the crankshaft. There is no need to remove, modify or alter this part to install a reduction pulley of the supercharger.
>>
>>Cheers

Correct. The harmonic balancer is on the crankshaft and is removed when installing an aftermarket underdrive pulley (underdrives the various accessories that are driven off the crankshaft to "free up" horsepower) and has nothing to do with installing a reduction pulley on the supercharger. Unfortunately, our engines probably won't respond well to not having this harmonic balancer which would result in too much crankshaft vibration and failure of the engine. Basically, supercharger reduction pulley = okay, crankshaft underdrive pulley = not such a good idea.

 

Stay away from any power pulley AKA under-pulley. This is bad news, go to the Dinan website you will find an article on techinical justification of why it's bad for your engine.

 

>>Stay away from any power pulley AKA under-pulley. This is bad news, go to the Dinan website you will find an article on techinical justification of why it's bad for your engine.

On inline engines it is a bad idea, however on certain V6s it actually helps a lot. My friend's Nissan 300ZX twinturbo gained a healthy amount of hp and tq. from the underdrive pulley and he's got about 130,000 miles on his car with it on.

 

---> Esoteric, I'm assuming you're referring to the supercharger pulley. If so, it's glaringly obvious that you only change the supercharger pulley, and none of the other pullies in the system. The harmonic balancer has nothing to do with the supercharger pulley or its' installation.

Installing an underdrive pulley set on the Cooper S is a total oxymoron, as you will then have to re-gear the supercharger to obtain the correct ratio. The only thing you can possibly gain by changing to an underdrive pulley set is less drag from the A/C condenser, as there is no power steering pump, and the water pump is driven via the supercharger. Bottom line; don't turn on your A/C and you won't have a problem with drag.