Screech!
 

My 85 RX7 likes to screech really loud around 5k rmp, making redlining not really an option.

I have exploded a belt or two (no power steering, so only two belts) and have adjusted belt tensions a few times. Granted I have adjusted using the defraction of what appears to follow the manual guidlines, but haven't used an actual tool to measure it.

Should I get a belt tensioner? Is it not even a belt?

Thank you,
Sarah

Could also be bearings in one of the accessories, or the water pump. Might want to check those as well. Remove the belt from the PS and AC and see if it still does it.

cheap belts at a parts store are $4-5. Get new belts. adjust.

**running air pump? fan clutch? Make sure you have enough belt contact on the water pump pulley.

I've had an alternator or 2 that would do that. Especially once it had a load put on it.
Good luck.