-EFFECTS OF A LIGHT FLYWHEEL-
-EFFECTS OF A LIGHT FLYWHEEL-
September 6, 2001.
In the quest for going faster, a light-weight flywheel will sooner or later creep up on your "to do" list. Why a light-weight flywheel? After all, they cost upwards of $350 USD, and requires the hassle of taking the transmission out of the car. Well, the very obvious answer is the savings in weight. As a result of that, the engine is allowed to spin quicker, as it does not need to dedicate as much power to spin a light-weight than a stock flywheel. Which of course, translates into quicker acceleration, and more horsepower.
But is the weight savings that significant? For the 4AGE engine, the stock flywheel weighs roughly 16 lbs. A Fidanza flywheel weighs 9 lbs. So is the difference only 7 lbs.? 7 lbs. is not significant at all. Or so you think.
Rotating mass has energy in the form of rotational inertia, and because it is rotating, 7 lbs. may translate into weight savings of over 100 lbs.! Let me explain.
Taken from Dave Coleman's "Technobable" section that appears in the September 2001 issue of Sport Compact Car, rotational inertia can be translated into static weight by use of this formula:
The terms are easy to understand:
Let's put this
equation to good use. First, we need the gear ratios out of a C52
close-ratio (not C52 from 4ALC engine) transmission:
| C52 Transaxle | Reverse | 1st | 2nd | 3rd | 4th | 5th | Final Drive |
| 3.250 | 3.166 | 1.904 | 1.310 | 0.969 | 0.815 | 4.312 |
Since acceleration always begins in first gear, we shall examine the effects of a light weight flywheel in 1st gear.
Therefore, in first
gear, my car feels almost 145 lbs. lighter! Taking each gear into
account, my weight savings would look like this:
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As you can see, the effect of the light-flywheel tapers off as the gears go up. However, even in 5th gear, you have "removed" more weight than the actual static difference between the stock and the Fidanza flywheel!
So do I think it's worth it? Yes. The car feels very crisp in acceleration, very "free". I believe that anything that will help the 4AGE rev faster can only be a good thing. There really isn't a down side to a light-weight flywheel. For street driving, going under 9 or 8 lbs. is not recommended. Sometimes, during stop-and-go traffic, as soon as the engine is disengaged from first gear, the rpms dip down to 500 or so, and instantly come back up. Other than that, there isn't anything else I have noticed. Others say it is easy to stall the car with a light-flywheel. I haven't experienced this at all.
So in conclusion, replacing
the stock flywheel with a lighter unit is a very efficient means of removing
weight from the car, and thus increasing acceleration and power output.
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