Last night, I replaced my thermal pellet with the solid aluminum pellet. I followed proper procedure on keeping the clutch pushed in while performing the switch. Problem is, that when I was removing the e-shaft bolt, I had to keep the pulley from turning, and in the process, I bent the pulley.

Now, when the car runs, it makes a faint "clacking" sound every so often. I assume that this is caused by the pulley being bent. My question is, when I replace the pulley, can I replace just that one (which is the pulley that runs the AC belt) or do I have to replace the three as a set in order to make sure that they are balanced to each other.

I did a search and saw reference to the fact that the pulleys are "zero balanced"--which I think may mean that I can replace just the one pulley.

Hey, any information is appreciated. Thanks for keeping the RX7 Forums such a great community of rotorheads!!!

 

Sounds simular to what happened to me at the time of removing the Thermal Pellet. I wouldn't sweat It. Just use pliars, or simular, to straighten the edges out again.

Providing the 4 bolts line up to the Pullies, I wouldn't replace them.

 

I'm glad I'm not the only one. When I started the engine after switching it out, my heart just sank when I heard the noise---then I realized about the pulley. I'll know better next time!

I found a guy on the forum to sell me a set of pulleys pretty cheap, so I might just switch them out. I'll hang the old ones on the wall in the garage for decoration

 

if you dont buy the pulleys tell me who and how much.

 

I replaced the pulleys and everything is fine now. Thanks for the help!

 

hey do the pulley really help cuz i was thinking of buying some but i am not sure if they are worth it or if they are really beneficial

 

There are undrive pulleys and light weight pullies. From what I understnad undrive pulleys are not recommended for street driving. light weight pullies free up a minimal amount of horsepower because of less rotational mass. I think mazdaracing advertised more than 10whp which is very farfetched.

 

Just about every underdrive pulley is alluminum which means it is lighter then stock(MazdaRacing's pulleys weigh like 2# less then stock) The horsepower comes from underdriving the alternator and water pump. The weight only helps the engine rev faster which leads to quicker acceleration(like a light wieght flywheel)
If your car has very poor cooling(clogged radiator, faulty water pump or obstructed air path) then you may have an overheating problem when you switch to underdrive.
There is a dyno sheet on MazdaRacing.com showing the HP gain.

 

take a read and see if your mind changes.

https://www.rx7club.com/forum/showth...hreadid=224688