Light weight flywheel

[Donald]

Anybody have a lightweight flywheel installed?
Does it affect your low speed driveability?
Is there a noticeable improvement in performance?
Was it worth the cost?
What weight, what brand?

[4speedsleeper]

Well, nomatter what brand it is you can only take so much weight off and it should be 9 lbs if it is lightened they only weight in at 16 lbs.

[ToyotaTechGeek]

i have a custom lightened flywheel. i didn't go radical, but played it safe. when your flywheel is too light, drop-off when upshifting is experienced. up/downshift 'blipping' almost becomes a necessity since rpms drop-off so rapidly (as rapidly as they [flywheels] allow the engine to rev-up). someone once explained to me using a great analogy, and it has since escaped me, but flywheel weight is somehow related to torque.

[1991tercelasdf]

a heavier flywheel helps your engine to retain rotational inertia, but makes it more resistant to changes in rpm (it revs slower). this helps some when drag racing, but mostly on the launch, because it helps to keep the motor from bogging off the line. a lighter flywheel is great if you need to change rpm rapidly, like in rally or drifting, but otherwise, your engine may seem jerky, because it will react much quicker to your inputs.

[Donald]

Originally Posted by ToyotaTechGeek

i have a custom lightened flywheel. i didn't go radical, but played it safe.

So did you have a machine shop do it for you?
How much weight was taken off.


[QUOTE=1991tercelasdf; a heavier flywheel helps your engine to retain rotational inertia, but makes it more resistant to changes in rpm (it revs slower). your engine may seem jerky, because it will react much quicker to your inputs.[/QUOTE]


The jerkyness is what I am most concerned about.

Also, a co-worker of mine that used to race SCCA, told me that if I go too light, I might need to get a high torque starter since the inertia of flywheel helps overcome compression.

I am wondering what is a good weight, and is machining a stock one down difficult?

[ToyotaTechGeek]

Originally Posted by Donald

So did you have a machine shop do it for you?
How much weight was taken off.

I am wondering what is a good weight, and is machining a stock one down difficult?

yes, machining a stock one os VERY difficult. many people hack them up. you need some really specialized equipment to do it properly. i machined mine. 6 lbs is about the max you can safely remove without risking things like warpage and loss of integrity.

[Donald]

Originally Posted by ToyotaTechGeek

yes, machining a stock one os VERY difficult. many people hack them up. you need some really specialized equipment to do it properly. i machined mine. 6 lbs is about the max you can safely remove without risking things like warpage and loss of integrity.

So you did it yourself? Dam! I wish I could do that stuff.

Is your car a daily driver or just a track car?
Did it make starting harder?
Is the driveability difference (Jerkyness, having to blip the throttle) annoying on the street?
What is the stock weight?
Do you think a 2 or 4 lbs reduction be worth the effort?

[ToyotaTechGeek]

yeah, me and my pops machined it one afternoon. after i did that, i took it and had it balanced. i believe i took approx 4 lbs from it...mostly 'cleaning' casting flash and re-shaping the shoulder on the backside of the flywheel. i also zeroed on the two factory lightening holes and then went and machined 2 90* holes from each then i elongated all of the holes by about 20* on either side. i stayed clear of trying to remove too much material so that i wouldn't run into problems with warpage. maybe i can take a pic so that you can see. the only thing is i don't have another factory flywheel with which to compare.

the car is a daily with track capabilities. starting was fine. i up and downshift blip anyway...even on the street...keeps me sharp on the track!

[Donald]

Has it helped noticeably with accelleration?

[1991tercelasdf]

toyota tech geek, if i sent you a tercel flywheel, could you machine it for me? i will pay money....

[ToyotaTechGeek]

Originally Posted by Donald

Has it helped noticeably with accelleration?

kinda hard to tell with my setup. i've got so many things (mods) that it's difficult to tell just what 'did' what. but yes, my car feels much, much better than it did stock with BPU's.

[ToyotaTechGeek]

Originally Posted by 1991tercelasdf

toyota tech geek, if i sent you a tercel flywheel, could you machine it for me? i will pay money....

we will have to see. sounds like fun, but i don't machine for a living nor do i turn wrenches anymore [thank GOD!] -and- i'm in the middle of a very large project involving my AW11SC right now.

[Paseo15psi]

It's hard to find a lightened flywheel for the 5efe now. Yet another reason why I'm going back to a 4efte in my 92 Paseo. I do have one in it now with the 5efhe and it is great on the track, but you kinda have to blip the throttle and hold revs while circuit racing anyway. It does suck on the street though. I find myself holding the revs with the throttle in between gears and that is taxing when you must deal with pot holes, traffic lights, and idiot drivers.

[Donald]

I posted the same question in the Corolla (AE92) forum and no one over there seems to have one.
It did raise quite a controversy though, about whether it helps accelleration or not.

The street part is a big concern too. If it makes daily driving a chore, that's not good.

Oh well. Just one of those things inquiring minds want to know.

Thanks for the replies fellows.

[ToyotaTechGeek]

yeah, that is why going too light is not so good. the single most asked question should be: what will the car be used for? will it be street, drag, autocross, roadcourse, or a combination of two or more?