replacing the clutch on my b16 with Y1 with LSD with an ACT clutch and want to get a lightened flywheel in there while i'm at it. I will be getting a clutchmasters flywheel because they are cheap. but the question is:

7.5 pound, 9.5 pound, or 11.5 pound?

the car is a daily driver with occasional stints to the track or to autocross.

 

IMO you don't want one that is too light becuase you want the weight to keep the engine moving smooth. If you JUSt use your car for drag then the lightest one would probably be best becuase you would rev fastest, but for driving around town; a heavier one would be better in two ways...
1) better if you ever get stuck in traffic or have to stop a lot @ traffic lights
2) the weight will resist sudden changes in motion by the crank, so the car will run smoother

So i see it as a compromise, but i would probably go with the 11.5 becuase my car is a daily driver. If i had just a drag car then by all means...the 7.5 would probably be great. Personaly i have a 2000 ITR flywheel

 

i have the exedy lightened flywheel..i'm not sure the exact weight (around 11 lbs?) but the engine revs faster, and i have no adverse effects in daily driving.

 

from the combinations you have listed I had all....
12lbs stock shaved unit
8.5lbs Cusco
7lbs Fidanza

all defiantly reved nicer then the stock unit but the 12lbs seemed as the best as far as deily driving and when drag racing.....the fidanza unit is excellent especially for autox, but a little too light on a b16a when trying to keep the momentum when shifting....

no matter which way you go....all are good choices

 

11.5lb clutchmaster

 

a friend of mine has a 8.5 pound TODA flywheel, he got his for $400 to his door. his car runs a smooth as a stock 2000 SI. as for revving, i give it a 10. and a thumbs up. no problems driving around on the street. i would not be interested in clutchmasters product. TODA flywheels and EXEDY clutches are #1 in my book.