What difference, if any, is there between the ACT counterweight and the Mazda 52x? Last time I looked the Mazda one wasn't there (On BHRs website).

 

ACT one is balanced for a 6port and mazda one bakanced for a 4 port apparently. I have used both on a 6port though so dunno.

 

1986-88 13B All (Mazda # N3Y8-11-52X)
1989-95 13B All (Mazda # N3Y2-11-52X)
2004-11 13B RX-8 (Mazda # N3Z2-11-52X)

 

Does one need to be looking at any specific flywheels for an automatic, or will they all pretty much have the same effect as on a standard transmission?

Thanks!

 

There is no flywheel on an automatic. There is a faceplate that the starter teeth engage....but thats it

 

There is no flywheel on an automatic. There is a faceplate that the starter teeth engage....but thats it

 

Oh word. Damn, feel kinda stupid. Thanks for the quick response!

 

The balance testing I'm aware of indicates that the ACT counterweight requires more adjustment than the OE counterweight to achieve a finely balanced rotating assembly i.e. it was further off than the factory CW. Thats based on a very limited quantity and not using an ACT flywheel, but given how broad the OE balance variance is I can't see any justification beyond buying the least expensive CW option. The only way your going to get a properly balanced Renesis engine is to have it professionally done. IMO the factory component variance is one of the key issues/factors with Renesis durability. There's no way to address it by simply bolting on a part rather than an actual balancing procedure specific to all of the rotating parts on each given engine.

 

I agree......and despite what a few on here have said about balancing....it makes a huge difference

 

So essentially, when we purchase a flywheel and CW set, we should go and get the CW balanced at a shop anyways? For instance, even if I was to get a Mazdaspeed flywheel (which comes with the counterweight), I should get the CW balanced, despite it being a Mazdaspeed product?

 

the engine has to be disassembled to balance it all properly.

Just bolt it on and get what you get otherwise.

 

Oh I see! I understand what you mean earlier now! Thanks for clarifying that for me!

 

Going to have to agree with this. Just installed my Racing Beat aluminum flywheel along with an Exedy OE replacement clutch. The car is definitely more responsive, but only for the first couple of gears... It's not all cracked up to be, but I find it more fun to drive Lol.

 

It is a lot easier to shift at high RPM's...and easier on the transmission if you shift it wrong ;-)

With a balanced assembly and a light flywheel they spin up so much faster than with a stock flywheel

I wouldn't give mine back for anything

It isn't a horsepower producing mod though for those searching for numbers ;-)

 

Haha agreed. I definitely wasnt expecting any gains after all the research I've done, but I do love the new feeling of "lightness" and I don't plan on going back to stock either.

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So my novice question here is , are all counterweights the same? They all seem same shape and weight, what if any are the difference between all the counterweights available? Recently purchased xtreme flywheel fmz004cl at 4.31kg(9.6lb) but counterweight was unavailable and have ordered something i think "fits" however have probly ended up with a nice paperweight

 

You need the RX8 s automatic counterweight with any aftermarket flywheel.

edited out some of my response based on ACTman’s reply below
.

 

The one i ordered fits Prolite, EFT, ACT and Fidanza which got me thinking they were basically the same. Mazda OEM parts over here are crazily priced Team unfortunately.

 

Most aftermarket shops stocking counterweights have been waiting 2 months for them with an ETA of a further 2 months hence my gamble

 

Wow, I haven't seen this thread come up in a long time. The short answer is no they are not the same. I don't have time to review the 500+ posts so I will just re-post our findings for the RX8 counterweight:
1. All RX2-RX8 counterweights will bolt up the same but counterweight amounts vary greatly.
2. The RX8 automatic rear counterweight has a different amount of unbalance than the manual shift flywheel.
3. The RX8 front counterweight (counteracts the rear counterweight by being 180 degrees on the shaft) is different on the manual shift than the automatic.
4. Although not proven detrimental to the engine, IMO the correct course of action is to either change both front and rear counterweights to automatic counterweights or match the balance of the rear counterweight to the manual shift flywheel (which is what ACT does).
Phreakapotamus - Maybe I can help. Is it specifically for the RX8? If so they are all the same. If not, do you know the part number of the counterweight you purchased? Unfortunately it is not on the part, only on the packaging. I may be able to check records and tell how far off the balance is.

 

thanks for straightening this out, I’ve been incorrect on this point for a long time.

Which based on what a well known Renesis race engine builder told me; it’s all a crap shoot anyway without balancing the entire rotating assembly. Because based on his experience the component weights vary so much that the balance is often way off straight out of the factory. It’s one of the long term reliability issues with this engine. So for those people who choose to buy a factory rebuild engine rather than have it rebuilt, this is one thing you won’t get straightened out going that route.

 

I have heard unlike earlier Mazda rotary engines which were balanced as an assembly, the Renesis is only component balanced then assembled using complimentary balanced components.

 

From what I've been hearing the components aren't really self balanced either. I'm having to pull apart a new 21k mi engine with shot bearings likely due to poor balancing. Is it recommended to send in the counterweight AND flywheel for balancing? Are any of the flywheels decently self balanced to not need to be balanced again? I assume the stock flywheel was balanced from factory, I know my 85 rx-7 was, but I wouldn't be all that surprised anymore.

 

Kimura - Poor balancing should not lunch the bearings in 21k unless you are sitting on/near redline all the time.
Not sure what you mean by "self balanced" but my understanding is they would counteract the balance of one part (rotor for instance) with another part (the second rotor).
The OE flywheel is counterbalanced so there is no way to check except as an assembly. All aftermarket flywheels mount to the automatic counterweight and should be neutral balanced. If using an aftermarket flywheel, it should be balanced separately so parts can be changed later without major influence to the balanced engine. Not sure about other brands, but ACT has a maximum imbalance of .25 ounce inch. The clutch and flywheel can be done additionally to the assembly but position needs to be marked since the hole patterns are symmetrical.

 

We will find out. I don't know how PO treated the engine but I only saw bearing material in the oil in the last 1k miles or so, rapidly progressing the last few months. If by near redline you mean above 6k then yes. By self balance I mean the rotors themselves allegedly are often poorly balanced on their own, let alone when balanced together with the rest of the assembly.