View Full Version : Flywheel????


white_tC
02-20-2008, 02:08 AM
I was j/w'ing... does a new flywheel help at all?

Any power gains...cause im trying to get as much gains without going FI

GenericUserName
02-20-2008, 02:14 AM
revs slightly faster, more power is transferred through the system to the wheels

white_tC
02-20-2008, 02:21 AM
so is it a good mod to do?

engifineer
02-20-2008, 03:43 AM
No more power is technically passed to the wheels. This goes for reducing rotational mass in any way. A completely true method for measuring power is steady state (not accelerating or decelerating) , so due to the way a lot of dynos measure power, they are in a sense "fooled" by the quicker revving system, making them read more power.

But, a lighter flywheel will make a difference, and part of this is a small increase in acceleration. The car will be easier to rev match, will engine brake after throttle lift harder and will just rev quicker in general.

BlckdOutTC
02-20-2008, 03:44 AM
yeah, lighter=spins faster, therefore gets your power to the wheels quicker. It reduces that percentage of power lost from your crank to the wheels. You'll feel it too.

engifineer
02-20-2008, 03:54 AM
Actually, what I was saying is that it does not reduce loss to the wheels :) Being able to accelerate faster does not equal more power to the wheels necessarily. If it were truly reducing loss to the wheels, it would also do so at a steady rpm, which it has zero effect on. The same dyno that will read more power with a lighter flywheel will read the same if you put on lighter wheels and tires.. which in no way increase power to the ground. You are reducing the moment of inertia, which affects acceleration.

BlckdOutTC
02-20-2008, 03:59 AM
so just since it's lighter it just spins faster, using it's power more efficiently? Just reducing weight makes it naturally go faster right? Correct me if i am wrong please :-/

Soulquarian
02-20-2008, 06:32 AM
so just since it's lighter it just spins faster, using it's power more efficiently? Just reducing weight makes it naturally go faster right? Correct me if i am wrong please :-/

You are right. No additional power, just better access to the power you already have!

white_tC
02-20-2008, 11:09 AM
thanks for all the info...

if u got any more then just post it

BlckdOutTC
02-20-2008, 03:11 PM
oh alright thats what i was thinkin just couldnt pick and choose the best words for it. Thanks

Soulquarian
02-20-2008, 06:33 PM
thanks for all the info...

if u got any more then just post it

You can also get a lightweight crank pulley.

A crank pulley drives your accessories (a/c, alternator, fuel pump, etc). A lightweight crank pulley means less drag, which frees up more horsepower. Of course, your accessories will be less effective, but hey, anytime you do aftermarket mods, you compromise something...

Check around for more info. Lightweight crank pulleys can be bad too...

engifineer
02-20-2008, 08:16 PM
You are thinking about an underdrive pulley. Those do in a very small way free up power, but IMO not enough to be near worth the money.

An lightweight pulley, just like what I said above, frees up power in NO way, ever. Just because it revs faster or accelerates faster does not mean you freed up power. If it is sitting at a static rpm, it cannot pull any harder than stock with that mod, meaning no power was freed up. You only reduced the moment of inertia of the crank.

And I have still yet to have one person prove all those false dyno reading from a lightweight pulley to me. I have seen those that claim 12 hp on a dyno get ZERO improvement on the 1/4 mile. One guy claims he has gotten .1 sec in 1/4 mile from one, yet I have seen no timeslips to confirm he ran so consistant that .1 sec was even provable to be just due to the mod.

As far s the rest on these:

http://www.yoursciontc.com/forums/index.php?showtopic=14934

Will it die outright on you? Maybe not.. who knows
Will it shed 20,000 miles off engine life? Never know, and couldnt prove outright it was the pulley or not

Is it worth the chance of any of the above happening for a tiny, tiny gain in performance? Hell no IMO.

Get the flywheel :) Much better choice, more effect on performance and easier on the engine down the road.

Rule of thumb:

If it is easy and cheap, it is most likely not the magic bullet for performance. It just doesnt work that way :) At least on a decently engineered car.

BlckdOutTC
02-20-2008, 08:25 PM
man what dont you know about cars lol. i know you over from ystc also and i always take your word for things

TimmyT
02-20-2008, 08:28 PM
i have a CM flywheel coupled with my supercharger :D it makes a difference.

SVicksTC
02-20-2008, 08:45 PM
What is the ballpark for flywheel clutch install?

kikcaffine
02-20-2008, 09:07 PM
Pulleys will actually make the car rev up faster due to less of a rotational mass on the belt system. Pulleys are a good bet to go with if you want cheap horsepower. Check out www.nonstoptuning.com, they sell a top notch product

TimmyT
02-20-2008, 09:17 PM
I had my LSD, clutch and flywheel installed at the same time. It cost me about 950

xezerax
02-20-2008, 09:27 PM
if you plan on changing your clutch i would deff upgrade the flywheel too, i love mine. install time is probably around 7-8 hours and with labor approx $100/hr figure $700-800

engifineer
02-20-2008, 09:38 PM
I am going to give up on explaining that rotational mass has no effect on hp :P

Thanks for the comment blckdout! I dont claim in any way to be a super guru or anything of the sort, but when you grow up with your old man making you learn to fix your own (he is a mechanic), and he is a good teacher, you just pick it up over time! Especially when you have little money, and you grow up driving beaters you have to fix all the time :rofl: Seriously though, he is a d@mned good mechanic and I was lucky to have learned from him. The physics stuff just came from my college, and the geeky side of me that came out in college :D

The labor for changing one will vary by location and shop. I am guessing PA is somewhat like it is here in the Twin Cities (aka, everything overpriced), so your labor will probably be in the ballpark of 80 - 100 bucks per hour. They will probably hit you for about 8 hours as xezerax said above.

BlckdOutTC
02-20-2008, 09:50 PM
^^ No problem at all just figured you deserve some respect lol. Yeah i love working on my car and I do all my own work (except mounting tires, aint got that machine lol). My friends come to me to i save them some money as well. I guess like you I've been brought up to do my own work and it has payed off!!

engifineer
02-20-2008, 10:56 PM
It is definitely a money saver! Plus, at least that way, even if you make a mistake, you know who worked on it :D

BlckdOutTC
02-21-2008, 05:26 AM
hahaha that is true. Always something new to learn or improve at too