How often should the pulleys be replaced?
The idler pulley should be replaced every 120,000 miles, or sooner if they start making noise.

How do I save the most money using these adapters?
If you save the pulley on the auto-tensioner from the 60K service, you will only need the long and short adapters to replace the two idlers with the two auto-tensioner pulleys you already have on hand. You won't need to buy any pulleys until 180K miles. At 180K, you will only need one of the upper idlers.

I didn't save the auto-tensioner last time. What now?
If you did not save the old pulley, you will need to get one of the upper idlers and one long adapter. Use the stock upper idler normally. Use the long adapter to use the auto-tensioner pulley you have on hand in the expensive location.

I don't want to use old pulleys on my car. What do I need?
You will need to get two of the upper idlers and one medium adapter. This will save you some money over buying the standard parts.

Why is the left hand side pulley so much more expensive than the upper pulley?
It's not anymore. When we developed the parts, that pulley was $210. It's now $70, so the cost savings isn't nearly as great as it was. Switching the tensioner pulley over using our adapter still saves some money.

I have a metal lathe, why should I buy these parts from 300 Degree?
You shouldn't. We are not making much money off this part, it is really just something to save TwinTurbo.NET members some money. Here is a dimensioned drawing so you can make them for yourself. Use steel or hard aluminum, brass is probably too soft. We used stainless billet for the prototypes, and thick walled DOM steel pipe for production.