Thread: SR Flywheels

There were 4 basic combinations of flywheels you could get from Fidanza.

Combinations are

1. 10 pound flyhweel that you have Vadim that has 108 teeth. This Flywheel was designed originaly by JWT using Nissan ring gears.

2. 10 pound Flywheel you that have that has 109 teeth. This flywheel was designes as they were trying to keep costs down with a generic ring gear made in the USA.

3 There is the 8.5 flyhweel. This flywheel comes with more aluminum removed off of the back of the flywheel and has 108 teeth.

4.There is the 8.5 flyhweel. This flywheel comes with more aluminum removed off of the back of the flywheel. and has 109 teeth.



There are also 2 styles of flywheel you need to look out for when ordering flywheel heat rings.

1. Older flyhweel has 20 bolt holes.
2. New flywheel like what Vadim has, has 16 bolt holes.

The 20 bolt hole flywheel is out of production now. This move was done for 3 reasons one was to save money. Why 4 less bolts, nuts and washers. The other reason is 4 less holes to be drilled to save time. The last reason was for increasing contact surface area for more friction.

So be specific when ordering heat rings and be sure to count the number of bolt holes.


Someone posted pics of the 2 diffrent weight 10 pounds and 8.5 pound flywheels from the back but I can not find them.

Yes Fidanza makes flywheels for JWT,

^Bingo. This is correct. It has nothing to do with the oem ring gear vs the aftermarket ring gear. How do I know? I have both designs.





^I've been wanting to know this as I couldn't get any answer for the longest. So they make both the 108 and 109 in 10lbs and 8.5lbs? Cool.

^With this info being said, are there four different part numbers? I would think so as they would be the best way to tell them about instead of counting the teeth about 5 times.

Can you post a pic of both your flywheels front and back.

There is also no need tocount the teeth of the flywheel as it can be plain as day which one is diffrent

The Nissan ring gear the theeth are basically square.

The other ring gear the corners slant inwards toward the flywheel.

Hard to explain but if you take a pic of both the ring gears it will be easily seen from the back side.

Good info there Miko.

I rephrased what the Fidanza specialist told me over the phone. It seems like he only new about the two different flywheels, 108 tooth and 109 tooth, not the whole weight difference and the amount of bolts used.

The older 20th bolt flywheel was discontinued.

When ordering the metal plate you must let them knw how many bolt holes it has as you will have a 50/50 chance of getting the wrong part

^This is the only pic I have right now of the two. The front sides of both are identical. I get another pic when I get home.

8.5 pound is on the left and 10 pound on the right

^Correct.

^Also, the one the left is 109 and the one on the right is 108.



^How would I be able to tell if both flywheels were 109 with the different designs or 108 with a different designs besides the parts #'s? I still don't know if there are 4 different part numbers as I think it should be.

^What should we be looking for from the pic?

you need a closer look at the ring gear