Originally Posted by Adrenaline
I've been doing some major research on this and from what I've read, 1st and 2nd gears will show a substancial improvement. In one of the articles I read where the stock flywheel was 25lbs with a 2.5L engine, in first gear it was equivalent to having 225lbs less in the car, nearly 80lbs in 2nd gear. It all depends on the gear ratios of course, but during a launch there should be noticeable improvement.
Well, remember, the heavier the flywheel, the more low-end torque it helps produce. The lighter the flywheel, the quicker the motor builds it's RPMs.
So off the line, you'll feel less pull... it'll feel weaker until it gets to around 3,000 rpms and then you'll start to see an improvement.
If you were going to drive your car on the highway ALL the time, racing around at high rpms, a lightened flywheel would be an excellent modification. Or, even if you were going to participate in something like the Petite LeMans or something... but, if your going to use it in stop and go traffic, stop light to stop light, you may want to consider keeping your stock flywheel.
These car manufactures don't just build a massively heavy flywheel cause they're stupid and they don't know any better... they build the flywheel in such a way as to give a good median between low-rpm torque and high-rpm horsepower. If all you want to do is just improve the "overall" power of your car, save your money and spend it on something else.
If you plan to rally or road-race your Solstice... then get this flywheel.
If anyone doesn't understand this concept, consider that the flywheel is a link between the motor and transmission. When you get that heavy flywheel moving, it acts like a spinning weight (balanced). The road is friction, and is constantly trying to slow you down, the heavier the flywheel, the more force it helps put against the resistance that is the road. It improves low-end torque until you begin to build rpms and then it becomes a hinderance.
Keep in mind, you MAY improve the quarter mile time by going with a lighter fly-wheel. But... when you're driving your car around in normal stop and go traffic, you'll have to practically floor it to get the car to accelerate as smoothly as say a GM sedan with the naturally aspirated 3800 motor.
Just FYI... keep that in mind if you're considering it.