custom ud pulley

[sam c.]

My new pulley showed up in the mail yesterday so I went ahead an put it on the car. Pretty nice looking piece... paid $200 and that included the necessarily shorter 8 ribbed belt.

[sam c.]

Removing the pulleys made things a lot more accessible IMO. Also, I didn't monkey around with trying to remove the old belt.. I was just throwing it away anyway so I just cut it off and pulled it out (after removing it from the tensioner so it didn't snap back and put out my eye!)

[sam c.]

I think I'm going to hold off on pursuing an even smaller pulley until I get the electric PS pump and electric water pump installed. That's quite a bit of added electrical loading and I don't want to over tax the charging system. If everything is good to go, I might throw a custom cut 3 or 3.5 inch pulley on there just to see what happens. I plan on sticking with the 4" pulley for now though to determine the impact of the other modified systems.

[Homeboy981]

Looks like your engine struck GOLD! Looks cool!

[stephen wilson]

You could also use a larger pulley to selectively underdrive one particular accessory, without changing the others.

[sam c.]

Originally Posted by stephen wilson

You could also use a larger pulley to selectively underdrive one particular accessory, without changing the others.

That is true. If u want my honest opinion, the value of these pulleys are that they under drive the water pump, the alt, and the PS pump. The AC is being under driven as well, but ur controlling that load with the panel on the dash in accordance with ur own preference. So if u drive it slower with an UD pulley but ur still too hot (in a convertible.. ), u'll just turn it up anyways so the AC is a none issue in my opinion. That just leaves the other 3 loads.

Its been proven that the other 3 loads are being over driven from the factory which is why ud pulleys work.

In my case, because I'm removing two of those loads and effectively giving their work to the alt, I may just find that it needs to be driven closer to the factory speed. I seriously doubt it but maybe.

The other potential benefit of the ud pulley is that they could be made lighter than the factory pulley and therefore give less rotational mass/inertia for the engine to have to overcome to rev. However, from what I've seen, all these UD pulleys are actually slightly heavier then stock. If I were to cut a custom pulley, that's one improvement I would def pursue - weight - even if it meant going to a different material such as titanium.

[sam c.]

Btw, replaced my idler pulleys yesterday... used just off the shelf 70mm pulleys that are used on dozens of Audi and VW cars. Price=$20/pulley. Found out too that the bearing on these pulleys are just an off the shelf bearing and super common. If you still have the stock metal pulleys, you can press out the old bearings and press in a new one for less then $4.