My Mazda 6 3.0L has a 27-lb flywheel. When I do the clutch this summer, I might upgrade to an 15-lb aftermarket flywheel ($350). I'd like to know if this would be an investment or a waste? Can we talk about heavy vs light flywheels?
Effects of flywheel weight
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the heavier the flywheel the greater the "slowing of the car when you let off the gas" .. also when reving the engine it should zing to redline much quicker...also dropping 12 pounds should free up quite a few ponies to the wheels ...if you have the $$ I would do it
I believe a light flywheel will zing to redline much quicker.
Wait wait wait. Be careful. Yes, a lighter flywheel results in less overall rotational mass, and less parasitic drag on your engine. Therefore, ideally, your car will do a 0-60 faster on level ground.
But beware; if your flywheel is too light, you will notice a decrease in torque when going up a steep hill. You will find that you must rev the engine higher to get the same amount of speed traveling uphill, due to the decreased inertia from the lighter flywheel. Depending on the car, engine, and how much weight you shave from the new flywheel, this characteristic will be shown in varying degrees. I'd suggest you find someone else with a Mazda6 that has done the mod (search Mazda forums) and see their results before going ahead. Good luck!
But beware; if your flywheel is too light, you will notice a decrease in torque when going up a steep hill. You will find that you must rev the engine higher to get the same amount of speed traveling uphill, due to the decreased inertia from the lighter flywheel. Depending on the car, engine, and how much weight you shave from the new flywheel, this characteristic will be shown in varying degrees. I'd suggest you find someone else with a Mazda6 that has done the mod (search Mazda forums) and see their results before going ahead. Good luck!
A lighter F/W will not alter the HP or the Torque of your engine, It WILL allow the engine to rev to the red line Quicker in neutral, and slightly quicker in the lower gears. It will also (slightly) lower the overall weight of your car. It will NOT help you launch the car from a stand-still without playing with the revs to prevent stalling.
I once calculated the power lost to a heavier F/W on a 1/4 run, it was a fraction of a HP!
I once calculated the power lost to a heavier F/W on a 1/4 run, it was a fraction of a HP!
Correct me if I'm wrong, but won't a lighter flywheel cause the engine to be out of balance?
Also, doesn't the flywheel and harmonic balancer have to be the same weight?
Also, doesn't the flywheel and harmonic balancer have to be the same weight?
Spitty is right. Get the flywheel too light and you will have a hard time getting off the line. In fact, you might have a hard time keeping the engine running, or rather, not be able to idle the engine. There is a reason why race cars (Indy I think, not follow racing) keep revving the engine when slowed down for the pits and its not to make cool engine revving sounds.
Kestas
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Race cars rev high because that's how the cams are timed for efficiency. They're valved to run the high rpms (11K?) and simply won't idle properly. Yet you can't set the idle screw too high or the car will waste gas during braking. I don't think flywheel weight has anything to do with it.
I just repeated from memory what I read in a book or magazine long ago. Yes the valving would be an effect also as we see hot cam street cars idle like a beater with burnt valves. At any rate, the light flywheel isn't going to be any help for a car like that at idle.
I just don't think they're worth the cost for a daily driver. Your RPMs will fall quicker between shifts, so you have to always quick shift like you were "racing".
In the 2.5L MX6/626/Probes, a popular mod was to use the flywheel from a v6 MX3 - it was 17-18lbs stock IIRC and very cheap to purchase. Went a little lighter w/o having to go too light.
In the 2.5L MX6/626/Probes, a popular mod was to use the flywheel from a v6 MX3 - it was 17-18lbs stock IIRC and very cheap to purchase. Went a little lighter w/o having to go too light.
The effects of a lighter flywheel will be felt most in first gear, less in second, less in third, and so on.
It does make a big difference in lower gears. It also helps with shifting.
Your actual HP and torque are not changed. There is simply less inertia at rest to overcome. That's why it is most effective in the quicker lower gears.
For the average citizen tooling around town, a heavier flywheel is easier to drive. For an enthusiast and best performance, there is an advantage to a lighter flywheel.
It does make a big difference in lower gears. It also helps with shifting.
Your actual HP and torque are not changed. There is simply less inertia at rest to overcome. That's why it is most effective in the quicker lower gears.
For the average citizen tooling around town, a heavier flywheel is easier to drive. For an enthusiast and best performance, there is an advantage to a lighter flywheel.
It will be harder to take off from a light with a light flywheel. It will rev quicker. The engine may seem to not be as 'smooth' with the lighter flywheel.
As said by others, a lighter flywheel will enable the engine to rev quicker due to less inertia to overcome. The idle will be rougher also. Spitty is correct about increased difficulty in launching the vehicle; some early Hemi racers used to run with flywheels weighing up to 70 pounds...!
A heavier flywheel will smooth the idle somewhat and make launching easier, thoough the engine will not be as 'snappy' throttle-wise because of the extra whirling iron. I've often thought that a heavier flywheel may help with gas mileage though it's pure speculation on my behalf.
A heavier flywheel will smooth the idle somewhat and make launching easier, thoough the engine will not be as 'snappy' throttle-wise because of the extra whirling iron. I've often thought that a heavier flywheel may help with gas mileage though it's pure speculation on my behalf.
Depends on what you're looking for. The flywheel/engine has a certain spin-down time (momentum). If you like to get into the rthyum of smooth shifting without loading the tramsmission sycros the flywheel weight become improtant. I lighter flywheel will reduce the spin-down time requireing you to shift faster to maintain the smooth rthyum. I need a spell checker for this one. Sorry. I hope I've explained it correctly about the spin-down time and shifting sequence. O-Well.
That does make sense Eddie.
Other Mazda 6 owners who bought this flywheel gave mostly positive feedback. Nobody reported major issues with stop/go driving, hills, shifting, or anything else for that matter.
What is the practicality of getting a lighter flywheel? For example, fuel consumption?
Engine/transmission wear is another crucial factor. Is engine tuning designed around the flywheel in any way (or vice versa)? Is a change in noise vibration harshness probable? All these factors are of interest.
Other Mazda 6 owners who bought this flywheel gave mostly positive feedback. Nobody reported major issues with stop/go driving, hills, shifting, or anything else for that matter.
What is the practicality of getting a lighter flywheel? For example, fuel consumption?
Engine/transmission wear is another crucial factor. Is engine tuning designed around the flywheel in any way (or vice versa)? Is a change in noise vibration harshness probable? All these factors are of interest.
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