I was bored and happened to be surfing around SC parts and noticed XAT recently started making these:

https://www.suprastore.com/xatra1uz3uzb.html

No clue if they would even be worth it on our engines, but I've noticed nice throttle response improvements on 4 cylinder engines. That being said, there's more torque in 1 3uz cylinder than those engines had, lol.

I wouldn't go ripping things apart to do this upgrade, but something to consider next time the timing belt is due for replacement.

 

I watched this awhile back.

 

Great video, I recorded the weights for anyone curious in the future, incase the video gets taken down.

Stock Weight / XAT Weight: Delta
Power Steering: 713g / 266g: -447g
Alternator: 742g / 336g: -406
Idler: 300g / 200g: -100g
Water Pump Cover: 345g / 230g: -115g
Tensioner Pulley: Didn't fit

Total weight loss: 1068g = 2.35lbs.

Like he said in the video, it's probably not going to result in much of a performance increase. 2.35lbs rotational mass of a Miata engine would probably be useful, off ours, my guess is probably not noticable. Still, I'm glad to see new parts being made for our engines.

 

I decided to do a little math after reading this:
https://www.w8ji.com/rotating_mass_acceleration.htm
https://www.botlanta.org/converters/.../flywheel.html

The bottom line is unless you're dealing with a flywheel which, has a large diameter (around 13") and can be lightened by many lbs, you're basically looking at like 1hp for all of the pulleys combined, lol. (minus drivetrain loss)


Side note: If you ever have the chance to do a lightened flywheel in a manual car, it makes it REALLY fun to drive. (fast revs, very responsive)

 

Big bummer having all that jingoistic flag dropping in backround.
Sheesh,get this guy in politics-his kids are cute and he appears honest (though he appears a bit like Christopher Walken).
Can't say I like his leanings pol. but they aren't supposed to be a part of this site anyway.

 

I had a 1996 320i with a lioghtweight manual put on (5 spd)....ddidn't make enough of a difference to notice!

 

I remember these things back in the day when I was playing with Honda's, I never bought them though the light weight pulleys. I recall some takes out the harmonic balancer and can cause damage to the engine?