Manual Transmission T56 | T5 | MN12 | Clutches | Hydraulics | Shifters

Difference in flywheel weights... and "seat of the pants"

Thread Tools
 
Search this Thread
 
Old Jan 15, 2009 | 09:54 AM
  #1  
General Jack's Avatar
Thread Starter
TECH Enthusiast
20 Year Member
Liked
iTrader: (4)
 
Joined: Mar 2002
Posts: 540
Likes: 1
From: Austin, TX
Default Difference in flywheel weights... and "seat of the pants"

So correct me if I'm wrong, but the stock LS1 flywheel weights about 24 lbs, and the lightest aluminum flywheels are 12.5 lbs, with billet steel coming in around 18 and chrome moly around 15.

Obviously, there is a huge difference between stock and aluminum, relating to quick revs and launching at the track, since aluminum weighs only half or so of stock

But how noticeable is the difference between the billet and the chrome moly, assuming its about 3 lbs (18 versus 15, respectively). Will the 3 pounds make a noticeable difference in the quick revs and/or launching? I'm talking seat of the pants. And will the 18 lb billet steel rev noticeable quicker than stock?
Reply
Old Jan 15, 2009 | 10:45 AM
  #2  
Nightrydass's Avatar
TECH Enthusiast
 
Joined: Aug 2006
Posts: 623
Likes: 0
From: In your sisters panties
Default

take a 7lbs dumb bell in your hand and rotate your wrist; take a 10lbs dumb bell and do the same thing.

you tell me
Reply
Old Jan 15, 2009 | 12:16 PM
  #3  
Aetos's Avatar
TECH Regular
iTrader: (4)
 
Joined: May 2008
Posts: 473
Likes: 1
Default

Originally Posted by Nightrydass
take a 7lbs dumb bell in your hand and rotate your wrist; take a 10lbs dumb bell and do the same thing.

you tell me
I tried, but I'm too weak to pick up a 7lb dumb bell




If what I've read is correct, 10lbs of rotational mass(ie: most things on the drivetrain) is equal to 100lbs of static weight. Meaning, if we take the theory that 100lbs is equal to .1 seconds on the quarter then every loss of 10lb rotational mass should theoretically gain you .1 seconds at the strip.
Reply
Old Jan 15, 2009 | 12:28 PM
  #4  
68birdls1's Avatar
11 Second Club
20 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (46)
 
Joined: Feb 2004
Posts: 1,667
Likes: 0
From: jacksonville, fl
Default

is this right?
Reply
Old Jan 15, 2009 | 06:49 PM
  #5  
Black02SLPSS's Avatar
TECH Fanatic
15 Year Member
iTrader: (5)
 
Joined: Nov 2006
Posts: 1,485
Likes: 1
From: Owasso, Ok
Default

Yeah that sounds right to me
Reply
Old Jan 15, 2009 | 09:02 PM
  #6  
teke184's Avatar
TECH Junkie
iTrader: (5)
 
Joined: Feb 2007
Posts: 3,183
Likes: 3
From: Key West, Florida
Default

i went from stock to the fidanza flywheel.

while i could tell a difference it was NOT a night and day difference. it did rev faster but as far as feeling it SOTP in a race situation, i just barely could tell.

so the difference from a 3lb change probably would NOT be noticable.


although there are guys who say they can fell the power difference from doing a throttle body bypass.....3hp
Reply
Old Jan 15, 2009 | 09:16 PM
  #7  
BarneyMobile's Avatar
10 Second Club
iTrader: (4)
 
Joined: Nov 2005
Posts: 789
Likes: 1
From: New Jersey
Default

Originally Posted by teke184
i went from stock to the fidanza flywheel.

while i could tell a difference it was NOT a night and day difference. it did rev faster but as far as feeling it SOTP in a race situation, i just barely could tell.

so the difference from a 3lb change probably would NOT be noticable.


although there are guys who say they can fell the power difference from doing a throttle body bypass.....3hp
Agreed, I have the Fidanza 12.5lb fw and what I notice the most was the motor rev'd quicker but seat of the pants was almost unnoticed. It will show a difference on the dyno though.
Reply
Old Jan 16, 2009 | 08:15 AM
  #8  
teke184's Avatar
TECH Junkie
iTrader: (5)
 
Joined: Feb 2007
Posts: 3,183
Likes: 3
From: Key West, Florida
Default

i'm hoping i get an idea of gains from the light flywheel when i get dynotuned next month.

granted there are other mods...but i think my torque will jump more from the flywheel than it would with the other mods.

seems i remember the dyno comparison of the alum driveshaft resulting in more torque but nearly 0 hp gain.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-1

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-2

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-3

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-4

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-5

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-6

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-7

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-8

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-9

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
Old Jan 16, 2009 | 08:30 AM
  #9  
General Jack's Avatar
Thread Starter
TECH Enthusiast
20 Year Member
Liked
iTrader: (4)
 
Joined: Mar 2002
Posts: 540
Likes: 1
From: Austin, TX
Default

Originally Posted by teke184
i went from stock to the fidanza flywheel.

while i could tell a difference it was NOT a night and day difference. it did rev faster but as far as feeling it SOTP in a race situation, i just barely could tell.

so the difference from a 3lb change probably would NOT be noticable.


although there are guys who say they can fell the power difference from doing a throttle body bypass.....3hp
Thanks, this is kind of what I was looking for... So it sounds like:
  • probably not a discernable difference between the 18 lb and 15 lb
  • maybe some difference between the stock and 18 lb
  • probably a noticeable difference between the stock and 15 lb
Reply
Old Jan 16, 2009 | 08:55 AM
  #10  
ghettocruiser's Avatar
TECH Fanatic
iTrader: (17)
 
Joined: Mar 2006
Posts: 1,746
Likes: 2
From: West Chester, PA
Default

My donor car/motor/trans was set up with a spec 3 and aluminum fly wheel. Im now running an LS7 which has a HEAVY flywheel compared to the alum. I noticed a pretty big difference in motor response. The alum. flywheel set up was a lot quicker to snap to redline...like if the tires lost traction. They'd spin up fast as lightening. While my car still revs great, there is a definate difference.

As far as the SOTP for power...I didnt notice anything substancial. Nothing worth noting.

As far as SOTP for drivability...BIG difference. The alum. flywheel made driving in traffic alittle touch and go. Launching required more revs than with the heavier wheel. There was no way to just ease the clutch out and start moving with the alum. I mean..you could, but it was a pain. Now, I can pretty much start off from a light with no gas.

I liked the alum...but ILl never go back. If anything, Ill find a middle ground somewhere because the LS7 set up is definetly a boat anchor. Heavy as heck.

J.
Reply
Old Jan 16, 2009 | 09:27 AM
  #11  
teke184's Avatar
TECH Junkie
iTrader: (5)
 
Joined: Feb 2007
Posts: 3,183
Likes: 3
From: Key West, Florida
Default

agree with the above

stock i could just let the clutch out easy, and it would pull out from a stop. but the alum fw just stalls out. some of this could also be due to having a race oriented clutch disk (stg 4 with no sprung center hub).

you most def have to give more revs to pull out

and i also agree with how fast the car runs to redline once the tires break free. i guess without really thinking about it much i assumed it was due to the power i was making. but the faster reving of the light FW makes sense too.

down shifts are nice, if you like to throw it through the curves. a light tap of the throttle to rev match and release the clutch. not as much of a jolt when dropping gears at above normal speeds/rpms.
i notice it alot more when i drop 4th to 3rd to pass someone...i generally don't rev match then since i'm in a hurry...it just snaps to speed and i'm pinned to the seat. ....with the TDs wailing!!!



if you are really in tune with how your car feels under WOT, or in a drag race situation, you probably will notice a considerable difference going from stock to any light flywheel setup. say if you hit the track weekly, but i've never had my car at the track in almost 6 yrs. and all i do around town is slow starts...and fast shifts for 1 or 2 gears.
Reply
Old Jan 19, 2009 | 05:49 AM
  #12  
SuperSport01's Avatar
TECH Enthusiast
 
Joined: Apr 2007
Posts: 709
Likes: 2
From: 336 NC
Default

I used a billet steel flywheel in my SS due to having issues with the fidanza aluminum one in my boosted honda.
Reply
Old Jan 20, 2009 | 08:31 AM
  #13  
ghettocruiser's Avatar
TECH Fanatic
iTrader: (17)
 
Joined: Mar 2006
Posts: 1,746
Likes: 2
From: West Chester, PA
Default

teke184 good call on the downshifting. I forgot to mention blipping the throttle was effortless. Just a tap would send the RPMs where they needed to be.

I might be crazy here...but I felt that my trans was alittle smoother with the light set up. Could just be the perception from the snappier revs...or my hydraulic issues etc etc. Just something I noticed when I did my second build and installed the LS7 clutch.
Reply
Old Jan 21, 2009 | 09:34 AM
  #14  
teke184's Avatar
TECH Junkie
iTrader: (5)
 
Joined: Feb 2007
Posts: 3,183
Likes: 3
From: Key West, Florida
Default

something to add...

i did notice a slight increase in high frequency vibration after my clutch/flywheel install.

not sure it was the fw's fault...but with less mass to soak up vibration...its possible.

then again i've got poly motor, trans, and torque arm mounts
Reply
Old Jan 21, 2009 | 12:30 PM
  #15  
fortmyerspolice's Avatar
TECH Resident
iTrader: (7)
 
Joined: Jun 2006
Posts: 908
Likes: 0
From: Fort Myers FL
Default

Originally Posted by teke184
something to add...

i did notice a slight increase in high frequency vibration after my clutch/flywheel install.

not sure it was the fw's fault...but with less mass to soak up vibration...its possible.

then again i've got poly motor, trans, and torque arm mounts
Did you get it balanced?
Reply
Old Jan 21, 2009 | 05:03 PM
  #16  
Viper's Avatar
12 Second Club
20 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (6)
 
Joined: Dec 2001
Posts: 4,909
Likes: 3
From: Cleveland, OH
Default

Good question:
"Did you get it balanced?"

I had mine balanced and it was off quite a bit. I have poly motor, trans, and torque arm mounts too and it's very steady now, and the trans feels smoother. I'm running a Fidanza aluminum and SOTP was not noticeable but revs are lightning fast now; you have to be on your game to nail a shift at redline in 1+2.
Reply
Old Jan 21, 2009 | 06:33 PM
  #17  
MeentSS02's Avatar
Kleeborp the Moderator™
20 Year Member
iTrader: (11)
 
Joined: Mar 2004
Posts: 10,316
Likes: 6
From: Dayton, OH
Default

I went from a 58 lb Ram Powergrip/Ram billet steel flywheel setup (as weighed by me - full assembly) to a 37 lb RPS setup, and I noticed a BIG difference. It was harder to take off from a stop (just had to relearn how to drive it), and it was noticeably quicker just cruising around when giving it some gas just to putt around.

Dropping 3 lbs? Probably wouldn't notice that as much.
Reply
Old Jan 22, 2009 | 07:21 AM
  #18  
teke184's Avatar
TECH Junkie
iTrader: (5)
 
Joined: Feb 2007
Posts: 3,183
Likes: 3
From: Key West, Florida
Default

didn't balance it, but contacted fidanza and they said it was balanced.

that doesn't mean it couldn't have been balanced better....but oh well.

when i pull it out again...i'll have it redone...by that time it will be time for a new friction plate...
Reply




All times are GMT -5. The time now is 10:30 AM.

story-0
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-1
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-2
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-3
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-4
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-5
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-6
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-7
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-8
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-9
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE