M50 engine upgrade : Thermoplastic WP Pulley

I just changed my aluminium water pump pulley to a thermoplastic one. It was half the weight of the aluminium pulley.

The car is faster and more perky !

The difference made by this one pulley was greater than a composite impeller water pump and a clutch fan delete combined. Yes, the pulley was replaced a few days after the wp was swopped and the fan clutch was deleted, so I could tell the difference.

I've looked online...most places are only selling the aluminium water pump pulley. Avoid ! Anyone who finds links to thermoplastic pulleys, please post them here and everyone seriously ought to rush out and purchase, especially those who intend to change or delete their fan clutch, or change out their wp, soon.

Am now in the market for a thermoplastic p/s pulley as well. Have not found that so far.

Turner motorsports sells a performance pulley and belt set for $250. Too expensive, imo, but worth looking at to understand the possibilities.

Padre, I humbly submit this for addition to your E34 upgrades thread.

rgds,
Roberto

p.s. Explanatory note : Anything that is part of the belt driven system, is a load on the engine due to its inertia. Lighten the components, and you'll reduce the load, thus increasing power to the engine. This applies to stuff like forged pistons, lightened flywheels and crankshafts, etc etc. However, anything related to the engine's internals needs to be very carefully investigated before purchase (and you'll likely need to purchase several elements together to ensure consistency).

I got my OEM replacement pulley from the stealership and it is not aluminum or metal at all. OEM material wasnt supposed to be aluminum. I dont know what thermoplastic is but mine is some sort of composite...

Originally Posted by 95 E34

I got my OEM replacement pulley from the stealership and it is not aluminum or metal at all. OEM material wasnt supposed to be aluminum. I dont know what thermoplastic is but mine is some sort of composite...

Thermoplastic is a kind of resin that can handle stress and high heat for years and years and years.

Did you get better performance on your engine ?

Thermoplastic resin sounds like plastic when tapped with a fingertip. 'Composite', that's often used on bmw water pumps these days, sounds distinctly metallic when tapped (however it does not sound like normal metal would).

What did your WP pulley sound like ?

Originally Posted by robertobaggio20

Thermoplastic resin sounds like plastic when tapped with a fingertip. 'Composite', that's often used on bmw water pumps these days, sounds distinctly metallic when tapped (however it does not sound like normal metal would).

What did your WP pulley sound like ?

Plastic i would say. Definitely not metaillic. I also have my busted old OEM one hanging in my cubicle and thats not metail either.







Neither (OEM) are aluminum, or even metal for that matter.

Mine certainly was aluminium.

I dont doubt that at all. My point is that M50s should already be fitting with plastic/composit/resin, pulleys.

Aluminum is more sensitive to tempertaures and is already a very malliable material, relatively. These pulleys are under alot of pressure, exist at high revolutions and in high temp environments. I would not trust aluminum on my car. A little road debris, maybe a very very very small rock or bit of pavement flings up, I would expect it to easily bend or dent a heated aluminum part which would throw off the balance of a rotational component, then youre throwing belts and accessories become damaged and you run the risk of fiery death.

Originally Posted by 95 E34

I got my OEM replacement pulley from the stealership and it is not aluminum or metal at all. OEM material wasnt supposed to be aluminum. I dont know what thermoplastic is but mine is some sort of composite...

It is Bake a lite , that is the material I believe !

Sent from my Desire HD using Bimmer App

Originally Posted by supertech777

It is Bake a lite , that is the material I believe !

Sent from my Desire HD using Bimmer App

Bakelite was invented nearly a century ago. It can't be bakelite.