I just noticed that the two S4 N/A rotors that I want to use in my motor for my car are a "C" weight and a "B" weight. Will that be alright? If this was for a customers car, I would definantly not be doing it, but since it's mine.....

I think it would be ok. Just don't do an A and a C, or B and a D etc.

CONTRARY to what PINEAPPLE RACING will install in customers engines:



a B and D do not balance out...





Now the question to answer: WHAT is the criteria used to "grade" rotors?

In the last two eninges i built I cleand them to pristine then balanced them on a scale. Removed the same ammount on both sides of each apex of the heavy rotor untill its the same weight as the light one.

[quote name='GMON' date='May 11 2005, 01:56 PM']In the last two eninges i built I cleand them to pristine then balanced them on a scale. Removed the same ammount on both sides of each apex of the heavy rotor untill its the same weight as the light one.


[/quote]





Still does not account for the dynamic imbalance. I need to video an out of balance set of rotors on the stand one day....................

Just get the whole assembly balanced and you won't have to worry about it.

Well I will install them in my motor and I will let everyone know how they do. I'm kind of pressed for time and need it together asap, otherwise I would be looking to match these rotors up with the right ones.

Mazda from the factory puts in rotors that are with in one letter of each other in many of their engine. It's nothing to worry about and will be fine. I would not go more than one letter though.