After putting a lightweight flywheel in my little fwd hot hatch and seeing how much more quickly the engine revved and how much easier it was to rev match....it has become a "must have" upgrade for me.

A heavier flywheel is helpful when drag racing cars that have low torque, like a rotary engine. The reason is that a heavier flywheel will store a bunch of energy before the green light, artificially improving the launch and 60 foot times. Beyond that, the lighter the better when it comes to ET's. For almost all cars, the better launch (if traction is available) is negated by the inertial losses, especially in the lower gears. This is both from a scientific standpoint, simulation and years of track testing.

Short and concise. Love it.

Had a lightweight flywheel in my accord ages ago. Made the motor rev happy, and was able to raise and drop revs at a moment's notice however when driving uphill without the lighter flywheel I only had to drop to 4th or maybe 3rd gear to make it up the hill. But with the lighter flywheel I had to drop to 3rd, or even second gear due to less rotational mass helping the engine push the gearing. Went from a nearly 23lb stock flywheel to a 17.5lb fidanza.

Thank you. Great video. What if the car will be used on a short circuit arranged by cones? Slalom on a parking lot, with very short straights (less than 15 metres) and sharp corner (90/ 180 degrees). Lighter flywheel or heavy?

great explanation, thanks!

Love your videos!! So helpful

The trans does not slow the engine down. The engine slows to idle when you put the clutch pedal in because because your also lifting off throttle. And the benefit of a lighter flywheel is lower inertia so the engine rpms drop/climb faster. Making rev matching up or down faster. The engine is mechanically disconnected when you push the clutch "in".

Nicely explained love your car by the way

The factory put heavy flywheels on to allow a smoother and easier driving experience. Yes the rotational mass is beneficial as a vibrational dampener but means it takes more torque to initiate the rotation but once it is rotating it will continue by itself for longer. Stored energy. A lightened flywheel is beneficial in many ways. From Launch to acceleration to deceleration and stopping. If you buy a cheap one then you will be disappointed as it will be out of balance which will increase the harmonics inside the engine that has the potential to break things and cause alot of rotational resistance slowing down the engine and causing power loss. (Torque) I would advise that regardless of what brand you get get it balanced and skimmed that way you are certain of its specs. I use an excedy lightened flywheel on my rb25det. It was skimmed and balanced before installing it. It was out of balance and out of square out if the box. I have spent in excess of 25k in the engine bay alone so an out of balance flywheel on it for how it is tuned for hight rpm and other things would cause vibrations that could easily turn my 25k into a boat anchor. So the 100$ for machine saves me alot in the ling run. .

Would this also apply to vehicles with a dual mass flywheel? Would one be able to shave a stock flywheel down or would one need to buy a specific lightened flywheel?

Very well explain, plain and simple. Great info!!!!

Don’t forget that when you disengage the clutch and the motor is spinning freely the flywheel weight is what helps prevent sudden drop in RPM as it’s rotating mass decreases the decceleration effect of passive compression in the engine. So a short shifter to quicken your shifts and even double clutching can keep revs steady and get through gears easily whether up shifting or downshifting. So if you’re driving the twisties a standard weight flywheel is fine considering you have a clutch and a gear shift to stay in the peak HP range. On modern cars a lightweight flywheel is a great way to generate phantom misfires and trick your car into limp mode which isn’t going to add performance that’s for sure. Downshifts and gear rattle can be harsh with lightweight flywheel because the tranny is spinning so much faster than the engine as the flywheel doesn’t keep the engine rotating at a matching RPM which can be pretty hard on tranny parts and the low end of the engine. Lots better ways to gain performance without compromising the reliability of you’re looking to improve a car that you also daily drive or want to be reliable

You hit the nail on the head ... If one has a 5 hp Briggs Engine that was turning a 500.lbs flywheel versus a 5.lbs flywheel, whitch of the two flywheels would have the most torque while spinning ?

Which lightweight flywheel and clutch kit recommend on a C5 Corvette?

Great video

Great video man, nicely explained. Been looking at getting a lightweight flywheel for my z32 tt for dem revs.

Hi Griffin, Thanks for your great video, I installed a lightened flywheel on my car around 5 years ago, it worked great for 5 years, now the clutch slips under heavy acceleration. Is it possible the lightened flywheel could be warped causing the clutch to slip and require replacement? Is there anyway I can test for this without pulling the flywheel out? Thanks

If you want a light weight flywheel and you also want to drag race, get a set of adjustable cam gears and short headers/intake manifold. The idea is that you are moving the power curb to lower RPMs. The cam gear can be set to give you power at low RPMs. This is ideal for a light weight car like the civics that can hook and go without moving so much weight.

That was helpful, thank you

Great explanation. For drag racing (and acceleration in general) you Most Definitely want to reduce rotational inertia as much as possible: the car accelerates faster in short gears. It is less noticeable in high gears only because the engine acceleration is less than in short gears but it never hurts. However, since there is less kinetic energy available during launch, the drivers must adapt their launch technique, typically rev the engine quicker to compensate. There is nothing wrong with launching from the rev limiter if the clutch can take it, the car on my avatar is a 300hp 4-cyl 2.0L N/A with a 5" clutch and it launches at 8,500 RPM :-)

All I’m here for is can you used an OE Exedy Flywheel with a stage 1 Exedy clutch?

great video.. thanks!

My vote yes on lightweight flywheel.

Good explanation. 👍🏽

Hey Griffin, question for you. I have a 65 mustang I am rebuilding. I have a 351Windsor and using a T5 Manual Trans. I'm NOT drag racing. Just a Daily driver. I'm looking for Flywheel info. Whats your thoughts on which one I should use? Thanks

My question is unrelated to this video, but what transmission are you running in your truck? I've got my own build going and I'm using a lsx 454 engine for sure but I'm wanting going to with a turbo 400 and a overdrive unit, but then there's also the newer 4L70's or 85 that'll do the job without the overdrive unit. Any feedback will help, thanks!

So why do you hear chatter when u upgrade clutch and fly wheel

nice vid

I have a volvo 850 t5, I dynod the car with stock fly wheel then changed the flywheel for a lightened one and made more power to the wheels with the lightened flywheel than I did to the crank with stock 👍 lightened flywheel all the way

Love the video man ! really help in not buying the flywheel ! I was about to purchase one, but thanks to your video, i will not now.. i'll stick with the stock and just order new clutch ! Do you recommend Stage 2 Clutch on stock Flywheel ? Thanks

wow very short simple and informative video thank you!!!

Nice video. I have some mods on my accord 2.4 mt. 165kws 250nm. Replacing the clutch. Adding a 3.5kg flywheel. Do you have experience with this build, I'm uncertain about problems that may arise.

Mclaren F1, Carrera CT both have NO fly wheel. The revs drop tremendously during gear changes so it makes for a less "smooth" drive BUT for road racing it is superior if an experienced driver is on board. A weighted flywheel just helps keep the revs up during changes for those that don't have the skills to change up or down rapidly.

Hey I remember you. Same graduating class at UTI rancho haha

Sorry man , but revving quicker works equally well going straight as it does going around corners .

Press the clutch and off you go?

You should have spoken about the durability of them. I dont know the differences but I've heard different materials ware worse than others.

Let’s see before and after rev

Is it correct to say that ITBs will give you the same benefits of a lighter flywheel (faster throttle response), but without the disadvantages? Thanks for the video

whats ur take on putting a lightweight flywheel in a rx8, and does anyone know i you need tge counterweight if u go with a lightweight flywheel

I got light flywheel on my 300 hp car, its gd for accelerarion but it really sux with normal driving coz thr rpm drops sooo fast between gears

For race purposes, yes. For street, no: Driveline whine, decel vibrations, sometimes tricky engagement.

Does it matter if your car has blower or turbo on it.

Lightweight flywheels are great! Not too light though, or you'll loose drivability.

Modern manual cars with too mucb rev hang would probably benefit from a lightweight flywheel.

what is stock flywheel weight for g35 2006 v35?

Just use a plastic fly wherl

I did not expect to hear about Newton’s laws when clicking on this video 😂😂. Nice job explaining 👍

what are some brands you recommend?

wait a second... if it frees few bhp, for example 4-5 hp... how does that momentum in engine still makes you loose at drag race? what about racing from 20mph or from a dig? Does it changes only when you are out of gear(while you try to get into another) or in gear?

would a lightweight flywheel not be better for turbo cars take off time? as it revs faster therefore spooling the turbo quicker.

adding weight makes no sense, horse power comes down to speed. the faster you can accelerate, the faster you will get to where you are going, that is not to say that using certain light weight parts in your car will not adversely affect it...you are correct about having more weight in motion tends to slow down more slowly HOWEVER first you have to get that weight "in motion" and guess what? the heavier an object is that you have to move, the longer it will take!!! that's a fact. if you take 2 identical cars and add more weight to one and then race them witch one would you bet on your house on if you had to??? with that said, i have to disagree with you on that part.

Good day & good evening Griffin just having one new energy drinks in snack but taste is not good I miss all of you alot 😁😁😁😁😁😁🥤 making some very beautiful and sweet memories ....how about you how things are going 😁 cheers 🥤🍺🍵

I'm taking the lightweight flywheel OFF my C5 Corvette. It completely ruined the car. RPMs crash and sometimes stall out the engine when I push the clutch in at speed or between shifts. If it doesn't stall, the RPMs bounce around until it stabilizes which is really annoying. Really sucks in stop and go traffic. Yes this is after an expensive dyno tune to try to fix it.

i had a light one and did not notice any performance advantaje. and for a daily driver is not good

How is a lightweight flywheel on a daily driver? How much does it affect the ride quality?

Great point about drag race. It all I car about is 0-60

I have heard that a lighter flywheel gives more vibration/rattle in the cabin, for a street car does this affect the driveability of car and how annoying is this ? Good Video - Thank u

Just get the lightweight flywheel and call it a day.

Can a lightweight fly wheel be compatible with a stage2 clutch I have a Honda 2001 civic ex vetc coupe

With a light flywheel, you need a super good clutch. I have a 9.5 exedy and it won't grab. I can feel it slip at high rpms when I'm slamming to the gears. It is better for mountains. It climbs with ease that's what I notice. I'm still not sure what people are talking about being rough chatter for everyday driving. People not must know how to drive.

how’s about top speed with lightweight flywheel?

Aside from the performance aspects, there's also the street drive ability aspects to think about. With a lighter flywheel, you'll need to rev the car WAY more to take off from every stop sign , red light etc. You'll also get a lot more noise coming from the transmission and will make the car sound like a dump truck.

If you add the lightened flywheel you will need to get the crank balanced so you wont tear up some bearing

So of it frees up more hp why would u not want it for drag racing?

this video looks like what LSD trips might look like.

I always though of this, drag racing you want a heavier flywheel, road racing you want a light flywheel. Edit: you literally just said this lol

Only better for racing applications not for street driving.

Would this flywheel be bad for the track?

Wow The Comments people really?? If you care about performance and racing of any kind GET A LIGHTWEIGHT FLYWHEEL, zero people in racing use a heavy flywheel THOUSANDS of dollars spent making race cars lighter you really think they have the stock 20+lb wheel spinning in there? No it’s the lightest one they can find, and at constant high rpm aka drag racing rotational inertia isn’t as important.

Heavy flywheel allows the car to not stall easily

I have a question: I drive a MK7 Fiesta ST. And when I‘m driving fast, I change gears also too fast for the car(It can’t slow down the rpm as much as it should) So it also would be better in both directions...? So it would benefit me in increasing the speed of the rpm climbing up and also of getting the rpm faster down? I hope you understand what I‘m trying to ask. (English is not my motherlanguage😅)

52 pound flywheel? You drive a tank??? you mean 25?

Would carbon fibre flywheels ever be a thing?

faster more revs equal more motion blur so there.

love your sister so much @haileesteinfeld

Lol 52lbs.

How bout offroading.Trying to squeeze some extra power out of the engine...low - mid end torque is required...

Just make the car lighter another way. There is always someone faster than you are.

Light weight your car better lol

in 1:30 he's talking bullshitts. With clutch pressed into the floor (between the gears), flywheel is disconnected from the gearbox. The only mass which will be bonded to transmission (input shaft ) is clutch friction plate. The lighter it is - the less effort synchro rings needs to slow the input shaft down whilst clutch pedal is down. Lighter flywheel, apart from less resistance to engine when it increases its RPM, in the traffic environment (1-2-3, stop, 1-2-3 and so on) will also result in less fuel consumption. We've proven it empirically at UNI, verified on Ricardo Wave simulation SW and finally proof in real life vehicle.Simply, an engine requires to waste some torque to speed up heavy flywheel from n1 to n2, instead of transmitting this torque to your wheels. Also, heavy flywheel limits engine max RPM as some energy is needed to keep heavy mass at constant angular velocity. Simple exercise form young years - a moped with 2 stroke engine, after just removing totally flywheel, disintegrating flywheel to remove just a cam (for operating contact points - non-electronic ignition), installing just a cam for its own, was driving faster than with OEM heavy flywheel.No other mods been performed.