This is for a low budget racecar

Ok this is the deal, we have a 13B with S5 NA High Compression rotors, with a NA drive train.

The deal is, we have broke 3rd gear in the Transmission, so we are going to do a entire Turbo II drive line swap to eliminate the weak links.

What we have found is this, the S5 NA and TII uses the same counter weight, so this means the NA and TII Flywheels are interchangeable.

Also the S5 Turbo and S6 Flywheels are interchangeable. Same Counterweight and size.



The question I have is this, Can we install a S6 (FD) Flywheel into the S5 NA Motor and the motor still be balanced?



I am not worried about the Pressure Plates, they are the same between S5 TII and S6 (Except the Push/Pull Difference, but the mounting points are the same.


In my mind I say yes, but it would be nice to get a Yes/No on this.

 

If the counterweights are the same, I don't see why it wouldn't work since the engine will still be properly balanced. S4 are different weight from S5, thus they don't interchange. If S5 and S6 are the same, it will work in theory.....

I don't have real world experience with this setup, I am sure some more experienced users will chime in though....

 

hopefully this helps... http://rotaryresurrection.com/2ndgen...nter_info.html

 

Yeah, but Rotary Resurrection also says both s4/5/6 have 4.0 rear cw. But we know you can mix and match series but s5/6. I'm sure you can use the fd flywheel, I'm just about to use it within a couple of weeks.

 

http://webspace.webring.com/people/w.../flywheel.html
All S4s use the same counterweight while all S5s and FDs use the same counterweight. This might be contrary to some logic, but it's true. For instance S4 n/a rotors are different from S4 TII rotors, but they weight the same amount. N/A and TII flywheels are NOT the same. TII flywheels are larger in diameter. The S5 (89-92) and FD (93-95) rotating assemblies have the same weight and counterweight. Interestingly even though the S5 TII clutch is different from the FD clutch, the lighter stock FD flywheel can be used on a S5 TII. In other words you can pay $200-400 for a ~17lbs steel flywheel for your S5 TII or you can buy a used 19lbs FD flywheel for ~$30. In terms of aftermarket flywheels (externally balanced), you can use any TII flywheel on any TII or FD model, as long as you select the correct counterweight for your engine. I'm not 100% certain if the same is true for aftermarket flywheels for n/a models.
http://www.racingbeat.com/FRmazda3.htm
The weight of the stock flywheel is 22 lbs (89-91) and 19 lbs (93-95)
http://www.mazdatrix.com/faq/flywheel.htm
86-88 Turbo 318 ------- 27 lbs
89-92 Non-turbo 350 ----- 21 lbs
89-92 Turbo 370 --------- 23 lbs
93-95 TT N3A1 ------------ 20 lbs

 

This past year I did an S5 TII swap into my 89 convertible. I used an FD flywheel and it works great. As PvilKnight7 said it is substantially cheaper to go with the FD flywheel over an aftermarket and you get almost the same wieght reduction. My flywheel cost me 100.00 and that included getting it resurfaced.

 

I'm not sure if that part is true. Yes they use the same counterweight, but I believe the dimensions are different, the TII flywheel being larger than the NA flywheel.

By that logic, you cannot use an FD flywheel on an NA.

 

i'm not sure why it is worth bothering with for 2 lbs difference, is there a reason you have to use an OEM flywheel? you won't really notice a difference between the 2 performance wise.

to answer the question as best i can, no i don't believe the balance on S5 and S6 is exactly the same although they are close. if there is some huge underling reason why you really want to use an S6 flywheel then just have the whole rotating assembly balanced to match it. keep in mind you have to have a backup flywheel cut as well otherwise you will have to tear down the motor and redo everything if you need another flywheel replacement. yes it's a headache which is why i asked, why do it?

after looking into it a little more i suppose you could but i wouldn't want to guinea pig something like that without having the engine balance tested to verify. all numbers being equal it looks possible but iffy.

http://mazdatrix.com/faq/rotorwgt.htm

 

N/a and TII flywheels are OFF by 10mm (215 and 225mm).
Remember you are balancing the internals,not the Flywheel.
this makes me Mad that I didn't Weigh the Counterwights when I should have.When I had an S4 and an S5!..(I can't save the day with an answer!)

 

when you balance a rotating assembly you also balance the flywheel. it IS the rear counterweight.

 

If you think about it, since all the n/a s5 is high compression BUT the same weight, it should work out. It's balanced by weight not compression. Also it's easier to find fd flywheels then S5 TII oem ones.

Edit from above: You can't mix and match series but s5/s6 parts.

 

To clarify - on the car the original poster is inquiring about - its an S5 NA rotating assembly but being mated to a T2 transmission this time around. The NA transmission is being ditched.

This is why the larger FD flywheel is being used. The NA flywheel is too small for the T2 tranny going in obviously.

The FD flwheel isn't being chosen over a S5 T2 flywheel for performance, - we want to use it because we already HAVE an extra FD flywheel.

 

Since the rotors are the same rotors used in either engine (a part number check will confirm this), the counterweights are the same as well. Thus the stock S5 and stock S6 flywheels are balanced exactly the same. You could also check aftermarket manufacturers part numbers for both cars to see if the offerings for each generation use the same part. Intuition tells me so.

If you're using a TII transmission, then you are a-okay to go with the S6 flywheel.

There is a lot of misinformation in this thread.

All S5 and S6 rotors are balanced with the same front counterweight and rear counterweight. Knowing that, as long as your dimensions match (i.e. S5 NA tranny -> S5 NA clutch & flywheel/counterwight and S5 TII tranny -> TII Clutch & S5 TII/FD Flywheel/Counterweight), you can mate the above examples together.

 

As I stated above. I did a TII swap that included the full TII drive train and used an FD flywheel in the TII transmission. It is working perfectly with no problems. I know that the OP is wanting to use the NA engine but the balance is the same. When you go to an aftermarket flywheel, whether it is for an NA or Turbo you have to use the automatic counter weight from the same series S5 for S5 and S4 for S4.

That being said the S6 flywheel does work in a TII transmission whether it is mated to an S5 NA or TII engine. I know this for a fact because I am running that very setup.