NA Power Stage 3: More In-Depth Upgrades

[prlichtman]

Light Flywheel - important theory to remember

You can't simply say, a light flywheel will increase power. Any power increase only occurs during acceleration, and the amount of increase depends on the rate of acceleration. At top speed, for example, a light flywheel will give you absolutely zero power increase.

As an example, I put an aluminum flywheel on a supercharged BMW I built up. The power increase, by calculation as well as by feel, was 7 hp in 1st gear, 4 hp in 2nd gear, and not much in the higher gears. To understand what's happening you can go to any basic mechanical engineering book and look up power required to accelerate a rotating mass at a specified rate. But take my word for it, it checks out.

On the Mazdaspeed 3, if it's true that power is limited in 1st and 2nd gear by the factory, you may not gain much acceleration with a light flywheel. However, there may be other benefits, such as the nice feel when you blip the engine and it has a racier feel. How the sophisticated engine management of the Mazdaspeed 3 would affect this, I have no idea, being a new owner without much experience with the car. All I'm doing is stating some theory that's not widely recognized by hot rodders.

 

[tsunami]

just a reminder guys these mods are intended for the n/a mazda3 not the ms3... the ms3 has different tuning options avialable as well as many different stock parts like a dual mass flywheel that the n/a3 doesn't have....

 

[davens]

Great set of posts...nice to see some some dyno documentation.

But I'm going to have to disagree on the somewhat negative lightened flywheel statements.
I've had several lightened flywheels...a couple of hondas, my old '02 Protege, now I'm shopping for my 3.
It sounds like you went too light, which is a common mistake. And too light can be compounded by some of the crazy, excessive clutch options out there. It's been my experience, on a NA car, that a lightened flywheel works best with a very mild clutch upgrade.

I wouldn't look to a flywheel by itself as a great mod for the money, but when combined with a sensible clutch and short shifter, it enhances the whole package significantly.

I sold my 02 Protege to a friend...his non car enthusiast wife daily drives it with no problems. I even prepped her before they drove it the first time...she noticed that the engine was "zingy" but no had issues with engagement.

The only place I've seen it as a negative is at long elevation climbs...the engine has to work a little harder, which is presented as a slight decrease in mpg.
But I live in Texas and that isn't required very often.

 

[lucaspl88]

i agree...
i went ahead with Exedy lightweight flywheel (13lbs) and Exedy stage 2 clutch (3 puck sprung).
i never had a problem with engagement, just requires a little higher revs to get it going.. around 1300 to get a smooth take off, otherwise i love it !!! makes the car feel "zippy" in any gear..

 

[09WhiteBlackAzz]

im planning on all stages mods now lol