When using underdrive pulleys you need a shorter belt, correct? With the smog pump removal you also need a shorter belt, correct? when both mods have been applied to your car what length belt is then required?

 

Smog Pump removal makes you need a longer belt.... I think?

 

Has anybody done this modification? If so what belt length did you use?

I don't have smog, but am installing a crankshaft underdrive pulley and would like to know what belt lenght to use.....I'm thinking 95.8" but before I start buying belts and testing them a good reference starting point would be great

Thanks!

 

Just removing the smog pump from the belt routing (stock pulleys) requires a 96.8" belt. It's in the tech articles section of this board.

 

I found that, I actually had to install a underdrive crankshaft pulley (5.75") in place of the stocker (7.75") because the stock pulley was hitting the crossmember on my vette.

I wonder if there is a magic formula for figuring what length I now need starting with the 96.8" belt. It would make it so much easier than trying to buy, test-fit and swap for another if it doesn't work.

The crazy thing is that the stock belt using smog is supposed to be 94.56" long according to Autozone and Advanced...........shouldn't be longer

Thanks again

 

It's longer becuase you also have to change the routing. And the required routing takes more belt.

I usually go to the store, take my best guess and carry it out into the parking lot for a test fit. As long as the belt has never been RUN, you can return it. Installing for a test fit isn't running it. Get it?