Rotor weight , Picking correct counter weight
 

Put used auto counterweight and Mcloed rst clutch and flywheel on my fd , in higher revs it seams unbalanced and not smooth . How do I know what weight the counter weight needs to be ? Ft rotor is 4321 grams and rear 4353 grams don’t know what (rotor code) that is

Counterweights are only modified by the balancer.

ive heard that there is abcd code rotors and also counter weights to match those weights factory . How is one to put a aftermarket clutch/flywheel on with the correct weight counter weight without disassemble the motor to keep it balanced without vibrating ?

https://cimg4.ibsrv.net/gimg/www.rx7...a994a8a506.jpg

thanks very helpful …… glad your here

same to you :) gotta love the interwebz

all those “letter” rotors use the same counterweights. You’ll get the same half-crap balance the engine came with from Mazda. Not only is there a wide variance with the letters, but the cw’s too. Mazda’s version of Russian roulette so to speak.

the correct way to do it is to have the entire rotating assembly microbalanced properly, a highly under-appreciated service imo; Rob Dahm’s opinion be dahmed … :suspect:
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Without the front counterweight included in the mix too, it wouldn't be a balanced assembly anyway, if rear counterweights were available like that.

You could spin up the clutch and flywheel assembly for a hail mary. Not familiar with the brand, but unless they're made by gronks, shouldn't be like the bad old days of imbalance.

My rotating assy is balanced and lightened. quite a lot of machining was done. But smooth as butter all the way up.

"Mcleod RST clutch" awesome:)

if you are really having a balance issue it is probably something other than your rotor weights or the CW.

imbalance says hello on an exponential basis w RPM. if you are running near 9000 and above a lot i suggest a dynamic balance.

as to rotor weight... i don't look at rotor coding... i have found rotors 50+ grams apart with the adjoining letters. 50 grams is too much.

of course ideally it would be great if they matched. when the motor gets running the rotors take on lots of oil and probably differing amounts resulting in differing weights. your 30 grams diff is on the O K edge of acceptable if you are not spending all your time at 9000+.

i would look elsewhere and i would also consider it important to find the fix..

let’s not forget that 3 is a sacred number in the rotor orbiting universe 😇
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howard , this is a motor you built and was fine until the cd009 conversion using the auto counterweight you gave me and the flywheel and clutch from McLoed and the careless conversion kit , just doesn’t make sense with clutch push in and reved up that it vibrates more then normal now

pm

Best to have the complete rotating assembly dynamically balance! End Of Line.

Can someone move this to another section? Nothing to do with single turbo.