balancing rotors
 

I have a matching rotating assembly. 9.7 rotors, shaft, stat gears, and counterweights. but my e-shaft is toast. can i just replace the shaft and gears with my new Rx8 ones. or does it need to be balanced?

mainly im just wondering if i can just replace the rx7 shaft and gears with the RX8 ones without re-balancing the rotating assembly. also, if someone could explain the process of balancing. Im just curious on how it gets done and whats invloved...thanks.

I would send everything out to get balanced. Rob at Pineapple would be able to get this done for you. Reason why I say to balance your rotating assembly is cause even though the rx8 shaft is .5lbs lighter and its in the middle of the rotating mass it still makes a difference. I've seen first hand what a unbalanced motor and balanced motor revs like. Alot smoother coming from a motor that was completely balanced. Don't take my word for it, ask around and spea to the guru's. Good luck...

You don't need to get it balanced. If you are going to rev higher than 10k, then I would recommend balancing it.

is that an opinion? Or do you know for fact that you don't need to balance if your revving less than 10k?

It's always better to balance the complete rotating assy, including your clutch. Most of the factory rotary engines off the assembly line are far from being perfectly balanced. I myself am reving my all motor assy over 10k without balance with no issues and I know of many others going up to even 12k without issues. Having said that I dont' recommend it. Since he is only replacing the e shaft, which are pretty well balanced to begin with, and are low and in the middle of the rotating assy, he should be ok as long as everything else was in balance. If you want the most out of your engine, then it's always best to balance it. That goes for all motors.

I understand that its always better to balance everything. But i know you can always swap stat gears with no worries. and e-shafts too. as long as a the rotors matched eachother. I was just wondering about the rx8 shaft cause of the weight. I shouldnt be going any higher than 9k. its a turbo motor...

ok, so i'll just be swapping the rx8 stat gears and e-shaft in with the stock TII rotors. i think the rotors were balanced sometime in their life. got them from a JDM TII and looks as if they were machined already. Plus, the motor had upgraded springs and seals when i opened it up too...

side note... what if accidently mix up your front and rear rotor. and install them opposite. (front to rear, rear to front) would that make a difference. just curious...

The factory balance is good if you have the matching front and rear c/weights. Swapping stat gears is fine, but if you decide to use the rx8 crank you definitely 'should' get a balance done. I won't say 'must' as I haven't tried it without a re-balance, but I do know that the balancer I use takes into account the weight difference between the rx8 and earlier cranks.

13b rotors are interchangeable, meaning there is no front or rear like the 12a's.

Save your money... just change the E.Shaft and keep it under 10K . (-:

^ im just going to swap the TII stat gears and e-shaft for the rx8 ones. i wount be going over 9k. its a turbo motor and im sure my power band will drop off before 9k.