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Discussion Starter #1
Anyone know how i can get a light weight
flywheel to my dealer in Delaware by monday
To be installed with C/F clutch.

Thanks

David Turner
 

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call Focus Performance.. i had no problem gettin one overnighted to NJ right before christmas.. so that may b your best bet...

B
 

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Talk to Alan, I believe his name is PhocusZX3
he has a BRAND NEW FS flywheel that I planed on buying... PM me with your phone number and I'll see to it that he contacts you asap
 

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Originally posted by JPUR:
The UR Flywheel for the focus weights 9.5 lbs which is a great upgrade from the heavy OEM unit.

Gains of 18-24hp typical

Log onto www.unorthodoxracing.com for details

Hope this info was helpful
<font size="2" face="Verdana, Arial">Umm are you sure about that??? There are usually "zero" measureable gains from a flywheel. It increases accelerations, much in the same weight "lightening" your car would, but the difference cannot be measured in HP on a dyno.
 

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it frees up rotating mass on the engine...I would think it can give you more HP just as a lightened crank pully does...but I could be wrong.
 

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Originally posted by JPUR:

Gains of 18-24hp typical

<font size="2" face="Verdana, Arial">Ya, riggght.



- Drew
 

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hey mt ractive intake gave me like 45 hp more at the wheels, oh yeah wait i think it was the nawwz........... if i added up all the claimed gains i would have more power than tom.... i think they should not even post agins unless they post dyno's to prove it....
 

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Basic Rotational HP Calculation:

OEM Flywheel mass = 9.54KG or 21lbs
UR Ultra L Mass = 4.3kg or 9.5lbs

Diff of rotational mass = OEM mass - UR FL mass = 11.5lbs (5.227kg)

Crank hp = 2.7hp/lb loss ot crank (Ratio of HP gain) x 11.5lbs = 31.05 hp

Theoretical wheel hp gain = 31.05(crank) x .82(18% drivetrain loss for 5/6 spd) = 25.4 hp with oem wheels(may be less with aftermarket wheels)

I hope this explains the math a little and how I arrived at the estimated ~18-24hp gains.
 

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I do believe that a light flywheel will show gains in HP. Two reasons for this. First is simple, just by changing from heavy to light wheels cars have shown an improvement on the dyno. Less mass rotating really does mean more power. Second reason is this, you are spending energy making things rotate, part of the energy is used up making the engine go from x rpm to y rpm. Think of trying to get a 1000lb flywheel moving. You might be able to do it, but you would have little or no power left over on the other side of the flywheel to do any MORE work. Basically you burn gas, the energy expended is used to move the car, the less energy used to accelerate the rotating parts of the engine, the more of that energy can be used to move the car forward, so the end result is that the car is faster and you measure more power at the wheels.
EDIT: I though about this more and I'm sure you'll measure more power at the wheels just from a conservation of energy standpoint. You get a given amount of power from burning the gasoline, that didn't change. What did change is where you put the energy. With the stock system you put the energy into rotating the stock flywheel, it's a storage medium. With the light flywheel you store less energy so you have more to put to the wheels. With that said, each engine would read the same power at a steady state, it's only on acceleration that the engine with the light flywheel would show a gain in power.

[ 02-05-2003, 06:58 PM: Message edited by: familyman ]
 

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I'm not a mechanic or physicist but there are a couple of things that stick out in my mind. First, this dyno from FocusSport shows a run with a FS flywheel having a 112hp/119ft.-lb peak measure with their flywheel. Unfortunately there's no baseline on that dyno but certainly there's nothing close to the kinds of gains JPUR is claiming. The FocusSport flywheel is 8.5 lbs, so whatever the gains to be had, it should have more than the 9.5 lb. UR one. Also if there were major HP gains to the wheels, I'm inclined to think FS would mention something about it on their flywheel's page.

Second, even if I'm somehow misinterpreting the FS dyno no one from a company selling performance products should make claims about HP without the dyno charts to back them up. It puts the company in a poor light, especially given UR's slant on making precision performance products. I would indeed pay more for a better made product and have been looking at the UR flywheel and clutch but this kind of hand-waving calculation doesn't help my view of them. I don't mean to discourage JPUR from making comments, or UR from develop more Focus products, I'm just trying to point out that a company should either know its numbers or not mention numbers at all.

[ 02-06-2003, 01:58 AM: Message edited by: proxemac ]
 

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Yes it costs horsepower to spin up a heavy flywheel.

Where are you putting that energy?

Into the flywheel which is like a kinetic energy battery.

Where does that energy go? BACK TO THE WHEELS the next time you shift. So no, you don't really gain any horsepower because you aren't wasting any of it. Its just like having a shower running and you catch some of it in your hands and then dump it and it goes all back into the same drain (your wheels).

What it WILL help with (which is my motivation for getting one) is rev matching and acceleration in any given gear. For example, if you rev the piss out of it in 3rd gear and then get on the brakes... where does the energy of the flywheel go? Into the BRAKES this time... So for track racing its a no-brainer. For drag racing though I don't see any real benefit (at least not from any cost/benefit ratio).
 

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That's kind of what I meant by the transient HP gains and how it would read higher on the dyno. Since a given dyno pull in done in one gear, that pull would read higher. I don't think they're lying, I just think that what the truth means is open to some interpretation.
 

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ok...for people who do not think you will get a gain...think of this, what will show more power on the dyno:

a car with light 15" rims or a car with heavy 17" rims?

the car with the lighter 15" will show more power, so I dont know why a lighter flywheel wouldnt do the same thing. its the same damn reason they use lighter engine internals, it frees up rotating mass on the engine.
 
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