So my idea is this.... completely remove the idler pulley and buy a smaller belt to take up the slack. I figure the idler pulley weighs a half pound or so and a smaller belt would be just a tad lighter, so the gains would be small; but if there aren't any downsides, then there are worse things I could spend $7 on.

So I guess my question is this... what does the idler pulley do and why couldn't I just remove it for some rotational weight reduction?

 

The idler pulley keeps the belt tight. I don't think there is any other adjustment for the belt. How are you going to tighten up the shorter belt?

 

Everything is mounted rigid. There is no way to adjust the slack on the belt without the idler.

 

You are right..the gain would be very small. So pretty much a waste of time. Just take a crap before you drive....the difference would be about the same.

 

Im talking about the idler pulley, not the tensioner. The tensioner pulley is the one that keeps the belt tight.

 

I poop before every single time I get in my car, so I am looking for a little something extra with the idler pulley. Also, I make all my passengers poop before they ride, so don't bother telling me to do that either.

 

Its a pretty easy concept to do this. So why even make a post about it? Just buy a smaller belt, take the idler off, and your done! you free up 1/10th of a horsepower!

I think the main resaon for the idler is to put more contact surface on the tensioner, and the crank pulley. Perhaps Honda saw slippage issues when they were designing the pulleys/belt setup

 

This is exactly why I posted. I hadn't even thought of this as a use for the idler pulley.

 

I could tell you that my friend bought his S2000, and the prvious owner removed the tensioner...but kept the same OEM sized belt on it This resulted in a squeel on startup. We finally realized the idler was gone, so we added it...and also found out that the belt was so long for that configuration that the tensioner was "open" all the way...and not making the belt tight at all..

 

haha,