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8.4lb flywheel.....streetable?

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Old 07-10-08, 11:15 PM
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8.4lb flywheel.....streetable?

Ok, so just as the title states, is an 8.4 lb flywheel streetable as a daily driver? I've already ordered one in my haste......... I'm also curious to see what it'll do to my MPG? Let the flaming begin!
Old 07-10-08, 11:21 PM
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I've had mine on my n/a for about 5yrs, I got no complaints. Sure rev's a hell of a lot faster.
Old 07-10-08, 11:43 PM
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Originally Posted by RotaryWeaponSE7EN
I've had mine on my n/a for about 5yrs, I got no complaints. Sure rev's a hell of a lot faster.

My style of driving is to be as smooth as possible. Is it a challenge to take off without the car jerking really hard. I've read a lot of people saying that its almost impossible to be comfortable in the car, is this an accurate statement. My setup should be about 200 rwhp on an NA S4.
Old 07-11-08, 07:36 AM
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200rwp out of an NA S4 is big big numbers, what setup are you running?
Old 07-11-08, 07:45 AM
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dont listen to all those "light flywheel makes ur car un-streetable" crap, its all BS
i didnt feel the car being un-streetable at all back when i had the 9lb FW

the best way is to find a local guy with that flywheel and take the car for a spin
Old 07-11-08, 07:49 AM
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these flywheels are pretty expensive, are they worth it? I imagine they would be more helpful on a turbo car.
Old 07-11-08, 07:50 AM
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Originally Posted by Burnin_streets
My style of driving is to be as smooth as possible. Is it a challenge to take off without the car jerking really hard. I've read a lot of people saying that its almost impossible to be comfortable in the car, is this an accurate statement. My setup should be about 200 rwhp on an NA S4.
No its not a challenge, but it does jerk a little on some release points. Once you get use to it, it's a blast to drive. Makes a huge difference on how the car accelerates. I've got mine paired with a ACT 6 puck unsprung clutch. Its interesting on some softer surfaces.
Old 07-11-08, 07:51 AM
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only thing i can see wrong with it that is going to affect MPG is while on a highway your gonna have to stay on the gas due to the fact that it's going to have alot less inertia (sp) to eep moving on it's own so your speed will decrease quicker once you let off the gas compared to the stock flywheel has more weight wich equals more inertia.


Hope that help and you kinda get the idea.

Im prob going to go with maybe a 9lb or so. I didnt buy this car to be good on gas just to have fun. lol

Good luck
Old 07-11-08, 09:01 AM
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Originally Posted by a2dadamm
only thing i can see wrong with it that is going to affect MPG is while on a highway your gonna have to stay on the gas due to the fact that it's going to have alot less inertia (sp) to eep moving on it's own so your speed will decrease quicker once you let off the gas compared to the stock flywheel has more weight wich equals more inertia.
I really don't see it affecting gas mileage. Sure, it's apparently easier for speed to decrease with a lighter flywheel, it's also easier for it to accelerate. Seems to me that it evens out.
Old 07-11-08, 10:08 AM
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Originally Posted by My5ABaby
I really don't see it affecting gas mileage. Sure, it's apparently easier for speed to decrease with a lighter flywheel, it's also easier for it to accelerate. Seems to me that it evens out.
true. after you say that it makes sense that it would even out.

I was just thinking like when i drive to work on the highway i let off the gas to kinda coast a little and once i fell im slowing i get back on the gas a lil,

i figured with the lighter flywheel it would slow quicker so like for me i would pretty mych be constantly on the gas pedal which would consume more gas than i do now.

I gues it all depend on you driving.

Old 07-11-08, 10:15 AM
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It would slow Slower not quicker.....so your point is kinda BS. I drove my 8lb fidanza on the street and loved it. Very streetable.
Old 07-11-08, 10:58 AM
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I have the act prolight (I think 9lbs) on a mostly stock TII it rev's much quicker up and down. I also have the unsprung 6-puck disc, it makes it a little more difficult to take off from a dead stop but you will get use to it. I biggest problem I have is the down rev; it drops so fast that you really need to shift quickly to higher gears or it will fall off boost….that might have more to do with my turbo starting to fail.
Old 07-11-08, 11:01 AM
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Once you get used to it you'll wonder why cars don't come with them stock. The car really comes alive with it.
Old 07-11-08, 11:13 AM
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Originally Posted by siguy2k
It would slow Slower not quicker.....so your point is kinda BS. I drove my 8lb fidanza on the street and loved it. Very streetable.

I now drive his old 8lb Fidanza on the street and it's not bad at all. I sure do get wheelhop now when I take off and I feel like I will break my tranny soon but.... It is fun
Old 07-11-08, 02:24 PM
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Thanks for the input everyone! I too did not buy this car for its AWESOME MPG but I wanna see if I can get it close to the 30s. Stock on a motor with 186XXX miles I was making 22 MPG.

My goal is 200 or so. I am going to.....
1. Port and polish the motor -- waiting for total disassembly.
2. Swap in S5 rotors (looking for the rotors & weight) I have a pair of S4 rotors and the counter weight if someone wanted to trade or sell them...
3. Swap in an e-fan -- need to do research.
4. remove the secondary plates in the throttle body (completed)
5. tune it with haltech. -- we'll cross that bridge when we're there.
6. Headers (would like RB, but will probably be pacesetter) - I already have a gutted main cat and 3" from there on back. -- looking for a header, possibly used?
7. Short ram intake (less power, but better fuel economy) -- taken care of.
8. MSD ignition -- burn more fuel (more power and less waste)

I also have removed AC, PS and emissions. I think with that set up and the way I drive (like a little old man) I should be getting 26 MPG pretty easily. I'm also looking into pre mixing instead of the stock OMP. I think overall if I can tune it right, I'll have a half decent car and maybe hit 200hp! If anyone knows where I can get some parts from above that i need please PM me.

Last edited by Burnin_streets; 07-11-08 at 02:32 PM. Reason: #8 & #2
Old 07-11-08, 02:31 PM
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I also realize that the flywheel will not add any power, but allow the car to realize its full potential faster and remain there longer, all things held constant!
Old 07-11-08, 02:51 PM
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Originally Posted by Burnin_streets
Thanks for the input everyone! I too did not buy this car for its AWESOME MPG but I wanna see if I can get it close to the 30s. Stock on a motor with 186XXX miles I was making 22 MPG.

My goal is 200 or so. I am going to.....
1. Port and polish the motor -- waiting for total disassembly.
2. Swap in S5 rotors (looking for the rotors & weight) I have a pair of S4 rotors and the counter weight if someone wanted to trade or sell them...
3. Swap in an e-fan -- need to do research.
4. remove the secondary plates in the throttle body (completed)
5. tune it with haltech. -- we'll cross that bridge when we're there.
6. Headers (would like RB, but will probably be pacesetter) - I already have a gutted main cat and 3" from there on back. -- looking for a header, possibly used?
7. Short ram intake (less power, but better fuel economy) -- taken care of.
8. MSD ignition -- burn more fuel (more power and less waste)

I also have removed AC, PS and emissions. I think with that set up and the way I drive (like a little old man) I should be getting 26 MPG pretty easily. I'm also looking into pre mixing instead of the stock OMP. I think overall if I can tune it right, I'll have a half decent car and maybe hit 200hp! If anyone knows where I can get some parts from above that i need please PM me.
Sounds great, but to get to 200rwhp, you're going to need to have a pretty hefty port size, which should decrease your fuel economy pretty bad. Not to mention a standalone computer. Twenty-six miles per gallon may be a little far fetched, unless you're turning your engine off when coasting downhill.
Old 07-11-08, 02:59 PM
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Originally Posted by RotaryWeaponSE7EN
No its not a challenge, but it does jerk a little on some release points. Once you get use to it, it's a blast to drive. Makes a huge difference on how the car accelerates. I've got mine paired with a ACT 6 puck unsprung clutch. Its interesting on some softer surfaces.
i got the same clutch, and i got a 9lb zoom flywheel. I jerk a little when i first get going sometimes just takes some getting used to.
Old 07-11-08, 03:41 PM
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Originally Posted by TheAbsence
Sounds great, but to get to 200rwhp, you're going to need to have a pretty hefty port size, which should decrease your fuel economy pretty bad. Not to mention a standalone computer. Twenty-six miles per gallon may be a little far fetched, unless you're turning your engine off when coasting downhill.
Yea, I'm doing a large streetport! I think that in the low end it shouldn't be too bad as far as fuel consumption goes. I think in the higher RPM I'll loose hella gas mileage. I don't think 26 is too bad, I saw a guy on here making 27 running a similar setup. I don't think its out of reach at all. Just be optimistic and have a light foot. After I do my rebuild and run 3-4 tanks I'll post results!!!
Old 07-11-08, 03:47 PM
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Originally Posted by Burnin_streets
8. MSD ignition -- burn more fuel (more power and less waste)
good thought on most of those, but wtf is with burning more fuel here ? u want to burn more fuel and get better mpg ?

fyi stock ecu runs rich as hell already, the haltech idea is great, but look into the r-tek (spelling) if u want something cheaper.
Old 07-11-08, 03:56 PM
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Originally Posted by sub9lulu
good thought on most of those, but wtf is with burning more fuel here ? u want to burn more fuel and get better mpg ?

fyi stock ecu runs rich as hell already, the haltech idea is great, but look into the r-tek (spelling) if u want something cheaper.
What I meant by that is burning more of the fuel that isn't burnt in the normal combustion cycle. Like the left over fuel....stronger spark means more of the fuel will be burnt. Theoretical......probably but we all know the Rx7s run rich in general!
Old 07-11-08, 04:05 PM
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Originally Posted by sub9lulu
good thought on most of those, but wtf is with burning more fuel here ? u want to burn more fuel and get better mpg ?

fyi stock ecu runs rich as hell already, the haltech idea is great, but look into the r-tek (spelling) if u want something cheaper.
yeah i thought the same thing at first but i think he means the msd will burn for of the injected fuel. not that he wants to get msd so he can inject any more fuel then he is.
Old 07-11-08, 04:10 PM
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Originally Posted by fcforlife
yeah i thought the same thing at first but i think he means the msd will burn for of the injected fuel. not that he wants to get msd so he can inject any more fuel then he is.
Yea, I'm not injecting any more fuel, just trying to burn more of what is left over. Becoming, dare I say it, more efficient! That way too I'll have a better chance of passing emissions also.
Old 07-11-08, 04:18 PM
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You have 2000+ posts and you didn't understand what he meant?

I did. Right away.

Stronger spark will more USE the current fuel more efficiently = less fuel being WASTED (thrown away instead of converted into energy)

I think your setup sounds great, get the racing beat header, its worth it.
Old 07-11-08, 04:42 PM
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What makes the racing beat header superior to the pacesetter? Any additional flow? Additional power? Easier installation?



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