Weight of flywheel vs. overall weight of clutch kit - driveability
07-30-2018, 03:50 PM
#1
Weight of flywheel vs. overall weight of clutch kit - driveability There's something I've been wondering about and figured someone on here could answer the question for me. I'm aware of the pros and cons of a lighter aluminum flywheel versus a heavier steel one. As most of us know, it's generally regarded that a heavier flywheel is more streetable so to speak than a lightweight aluminum one is, all else being equal. What I'm trying to figure out is...from a driveability standpoint, is it the flywheel weight or the overall weight of the entire clutch kit (clutch disk, pressure plate, flywheel, etc.) that is the main driver?
Example:
1. Stock LS6 clutch kit = ~50 lbs. (stock steel flywheel accounts for ~24 lbs. of that)
2. Stock LS7 clutch kit w/ Ram aluminum flywheel = ~50 lbs. (Ram aluminum flywheel accounts for ~17 lbs. of that)
Both of the above setups have an overall weight that is the same. Only difference is the flywheel weight where the Ram aluminum flywheel with the LS7 clutch kit weighs 7 lbs. less than the factory LS6 flywheel. So given that, will the driveability be about the same since the overall weight is the same OR will the driveability nod go to the LS6 setup because the heavier steel flywheel?
Example:
1. Stock LS6 clutch kit = ~50 lbs. (stock steel flywheel accounts for ~24 lbs. of that)
2. Stock LS7 clutch kit w/ Ram aluminum flywheel = ~50 lbs. (Ram aluminum flywheel accounts for ~17 lbs. of that)
Both of the above setups have an overall weight that is the same. Only difference is the flywheel weight where the Ram aluminum flywheel with the LS7 clutch kit weighs 7 lbs. less than the factory LS6 flywheel. So given that, will the driveability be about the same since the overall weight is the same OR will the driveability nod go to the LS6 setup because the heavier steel flywheel?
07-30-2018, 05:27 PM
#3
If you can’t get a big v8 moving with a lightweight flywheel, I think you need to sell all your cars and move on to something else. Seriously. There’s more than enough rotating mass in there without a flywheel at all.
08-01-2018, 09:46 AM
#5
Anyone else want to comment on the example in my first post? I'm assuming the flywheel weight has more of an effect on the driveability versus the weight of the overall clutch kit just not 100% sure.
I have a Mantic right now but have been considering an OEM LS7 clutch with an aluminum flywheel so there won't be an overall weight penalty versus what I have now; however, I have no interest in doing so if the lighter aluminum flywheel will put a damper on the driveability versus the heavier steel flywheel I have with my Mantic (cam with decent overlap and picky as hell driver over here).
08-02-2018, 01:51 PM
#6
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I have a Monster LT1-S twin disc in my car with the lightweight flywheel and driveability didn't change. I installed a tick master at the same time so learning the new clutch pedal (which is much shorter and takes more effort) movement and engagement might have hindered a direct comparison. I do love the fact that I can shift at high RPM quickly, and the motor does seem to respond faster to pedal input in and out of gear.
08-02-2018, 02:57 PM
#7
I have a Monster LT1-S twin disc in my car with the lightweight flywheel and driveability didn't change. I installed a tick master at the same time so learning the new clutch pedal (which is much shorter and takes more effort) movement and engagement might have hindered a direct comparison. I do love the fact that I can shift at high RPM quickly, and the motor does seem to respond faster to pedal input in and out of gear.
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08-02-2018, 09:02 PM
#8
TECH Senior Member
I had both clutch setups you listed on my car without changing anything in between (no extra mods or anything that I could mistake for bad results). I was actually disappointed that the lightweight flywheel version made little to no difference in the way the car drove. Shifting was no different at all, and starting out from a stop might have taken a few more revs but if I let someone else drive the car they would have thought the clutch setup was factory stock...
I have a monster stage 2 now with the lightweight flywheel, and again there is not much difference in feel from that to the LS7/ram flywheel setup, although this one shifts smoother (likely due to me being used to the LS7 starting to lock me out of gear and being notchy...)
I suggest not getting the LS7 just due to the fact that the pressure plate can end up getting goofy on you and lock you out of gear in higher RPMs. Also its a very dusty clutch which will get your clutch fluid dirtier more quickly.
Was this in in a heavily cammed car or something?
As I said above I had both stock LS6 and LS7/lightweight ram flyhweel on my car with just bolt on mods and there was little to no difference. After doing heads/cam I don't have a stock clutch setup/heavier flywheel setup to compare to but it was definitely no problem to DD or anything like that. I could see if you are talking about something like a super lightweight flywheel maybe but the 17lbs ram flywheel isn't that light...
I have a monster stage 2 now with the lightweight flywheel, and again there is not much difference in feel from that to the LS7/ram flywheel setup, although this one shifts smoother (likely due to me being used to the LS7 starting to lock me out of gear and being notchy...)
I suggest not getting the LS7 just due to the fact that the pressure plate can end up getting goofy on you and lock you out of gear in higher RPMs. Also its a very dusty clutch which will get your clutch fluid dirtier more quickly.
As I said above I had both stock LS6 and LS7/lightweight ram flyhweel on my car with just bolt on mods and there was little to no difference. After doing heads/cam I don't have a stock clutch setup/heavier flywheel setup to compare to but it was definitely no problem to DD or anything like that. I could see if you are talking about something like a super lightweight flywheel maybe but the 17lbs ram flywheel isn't that light...
08-03-2018, 08:33 AM
#9
....
Was this in in a heavily cammed car or something?
As I said above I had both stock LS6 and LS7/lightweight ram flyhweel on my car with just bolt on mods and there was little to no difference. After doing heads/cam I don't have a stock clutch setup/heavier flywheel setup to compare to but it was definitely no problem to DD or anything like that. I could see if you are talking about something like a super lightweight flywheel maybe but the 17lbs ram flywheel isn't that light...
Was this in in a heavily cammed car or something?
As I said above I had both stock LS6 and LS7/lightweight ram flyhweel on my car with just bolt on mods and there was little to no difference. After doing heads/cam I don't have a stock clutch setup/heavier flywheel setup to compare to but it was definitely no problem to DD or anything like that. I could see if you are talking about something like a super lightweight flywheel maybe but the 17lbs ram flywheel isn't that light...
It was aluminum and it was not DD friendly.
08-03-2018, 09:27 AM
#10
10 Second Club
iTrader: (8)
^^^^likely because your tune was ****.
this
some of you sound absolutely stupid about the aluminum flywheel not being dd friendly. Like completely and totally moronic and should be banned from life in general.
ex1- hondas have about a 30lb clutch/fly assembly. Never heard anyone say their stock honda wasn't dd friendly
ex2- mustangs has had around a 40lb clutch/fly assembly since almost the dawn of time. Anyone ever drive a stock mustang? Well they have alot less off idle tq than a ls so it's a wonder they even move.
ex3- my 16lb clutch/fly assembly in traffic. With a faceplated trans
now....you have 2 cars making the same power. You have one with a aluminum fly the other with a steel fly and their corresponding weights. They racing.....who wins?
now throw the guy in the mix thats not a ***** and has his clutch weighing in at 16-30lb. You both will get to watch him drive out of your life.
some of you sound absolutely stupid about the aluminum flywheel not being dd friendly. Like completely and totally moronic and should be banned from life in general.
ex1- hondas have about a 30lb clutch/fly assembly. Never heard anyone say their stock honda wasn't dd friendly
ex2- mustangs has had around a 40lb clutch/fly assembly since almost the dawn of time. Anyone ever drive a stock mustang? Well they have alot less off idle tq than a ls so it's a wonder they even move.
ex3- my 16lb clutch/fly assembly in traffic. With a faceplated trans
now....you have 2 cars making the same power. You have one with a aluminum fly the other with a steel fly and their corresponding weights. They racing.....who wins?
now throw the guy in the mix thats not a ***** and has his clutch weighing in at 16-30lb. You both will get to watch him drive out of your life.
08-03-2018, 03:27 PM
#11
I don’t give a **** whether the flywheel is made of paper or iron, I’m just trying to understand for my own knowledge whether it’s the flywheel weight or overall weight of the entire clutch kit that has the largest effect on the driveability. Everyone has their own opinion on what is daily driveable or not, everyone has different levels of tolerance which we see all the time with camshaft selection. However, I’m simply just trying to understand how this all works. According to what I’m seeing I’m now leaning towards the overall weight being the main driver but I’m still just assuming things.
I’m personally willing to pass on the benefits of a lighter setup IF I can obtain better driveability (to me driveability goes well beyond just how a car is to accelerate from a stop). If I can have my cake and eat it to with a lighter setup then I’m all for it. Prob a good idea that I seek someone out with a lighter setup and a healthy cam that I could try.
I’m personally willing to pass on the benefits of a lighter setup IF I can obtain better driveability (to me driveability goes well beyond just how a car is to accelerate from a stop). If I can have my cake and eat it to with a lighter setup then I’m all for it. Prob a good idea that I seek someone out with a lighter setup and a healthy cam that I could try.
Last edited by StealthFormula; 08-03-2018 at 03:38 PM.
08-03-2018, 04:16 PM
#12
I don’t give a **** whether the flywheel is made of paper or iron, I’m just trying to understand for my own knowledge whether it’s the flywheel weight or overall weight of the entire clutch kit that has the largest effect on the driveability. Everyone has their own opinion on what is daily driveable or not, everyone has different levels of tolerance which we see all the time with camshaft selection. However, I’m simply just trying to understand how this all works. According to what I’m seeing I’m now leaning towards the overall weight being the main driver but I’m still just assuming things.
I’m personally willing to pass on the benefits of a lighter setup IF I can obtain better driveability (to me driveability goes well beyond just how a car is to accelerate from a stop). If I can have my cake and eat it to with a lighter setup then I’m all for it. Prob a good idea that I seek someone out with a lighter setup and a healthy cam that I could try.
I’m personally willing to pass on the benefits of a lighter setup IF I can obtain better driveability (to me driveability goes well beyond just how a car is to accelerate from a stop). If I can have my cake and eat it to with a lighter setup then I’m all for it. Prob a good idea that I seek someone out with a lighter setup and a healthy cam that I could try.
08-03-2018, 06:43 PM
#13
Lightweight setup on both of my manual cars (STI and 408 Z28). Both drive fine with it. Launching under power is where I have to slip the clutch a bit slower to control wheel spin and keep rpm on point. Took all of 5 minutes in a neighborhood to get used to normal driving.
Its about total rotating mass. Engine internals, flywheel, cluth/PP, driveshaft, axles, wheels... everything that transmits power.
Its about total rotating mass. Engine internals, flywheel, cluth/PP, driveshaft, axles, wheels... everything that transmits power.
08-04-2018, 01:07 PM
#14
10 Second Club
iTrader: (8)
I don’t give a **** whether the flywheel is made of paper or iron, I’m just trying to understand for my own knowledge whether it’s the flywheel weight or overall weight of the entire clutch kit that has the largest effect on the driveability. Everyone has their own opinion on what is daily driveable or not, everyone has different levels of tolerance which we see all the time with camshaft selection. However, I’m simply just trying to understand how this all works. According to what I’m seeing I’m now leaning towards the overall weight being the main driver but I’m still just assuming things.
I’m personally willing to pass on the benefits of a lighter setup IF I can obtain better driveability (to me driveability goes well beyond just how a car is to accelerate from a stop). If I can have my cake and eat it to with a lighter setup then I’m all for it. Prob a good idea that I seek someone out with a lighter setup and a healthy cam that I could try.
I’m personally willing to pass on the benefits of a lighter setup IF I can obtain better driveability (to me driveability goes well beyond just how a car is to accelerate from a stop). If I can have my cake and eat it to with a lighter setup then I’m all for it. Prob a good idea that I seek someone out with a lighter setup and a healthy cam that I could try.
second biggest is tune. There are ways to tune so the lighter clutch drives better even with a aggressive friction material like my 5.5 tilton triple with sintered iron discs in the vid.
dp simply don't know wtf he is talking about on this subject. By his theory a honda would be just totally undrivable. A stock mustang would barely get moving and i would only be able to take off when pointed downhill.
you can have your cake and eat it to. It's called a rps. That's the best overall alternative to something light with the aluminum flywheel(26lb) and very very easy to drive with stock like manners.
Last edited by HioSSilver; 08-04-2018 at 01:13 PM.
08-04-2018, 09:20 PM
#15
ModSquad
iTrader: (6)
RPS BC2 in my Chevelle and it drives metric tons better than my Diamond stage3. The Diamond clutch would chatter and shake the entire dash assembly terribly. RPS is silky smooth, and drives like my stock 94 Silveraydo 4x4 5 speed. I’m not kidding...
i was sceptical, trust me. You won’t regret the lighter clutch. The RPS is $$$$$.
i was sceptical, trust me. You won’t regret the lighter clutch. The RPS is $$$$$.
08-06-2018, 04:50 PM
#16
RST/RXT twin disc with a lightweight alum flywheel 12lbs is around 38lbs total. Drives great and it does rev a lot faster than a 50lb setup. As others have stated.... if you can't drive a car with 400 ft/lbs+ and a lightweight clutch setup then you need to relearn how to drive. The engine accelerates noticeably quicker especially 5000-7000rpm+. While the steel flywheel is easier to launch at the strip.... the lighter version just takes a little practice. Your grandmother could drive the 50lbs+ clutch/flywheel combo if that is what you are going for.
08-06-2018, 05:16 PM
#17
RST/RXT twin disc with a lightweight alum flywheel 12lbs is around 38lbs total. Drives great and it does rev a lot faster than a 50lb setup. As others have stated.... if you can't drive a car with 400 ft/lbs+ and a lightweight clutch setup then you need to relearn how to drive. The engine accelerates noticeably quicker especially 5000-7000rpm+. While the steel flywheel is easier to launch at the strip.... the lighter version just takes a little practice. Your grandmother could drive the 50lbs+ clutch/flywheel combo if that is what you are going for.
It's been well proven that a relatively heavy car (most fbody owners aren't into major weight reduction) combined with a light flywheel/clutch setup do not drive like stock. Plenty claim theirs "drives like stock", but there's a reason race shops don't recommend a lightweight combo for true street cars that rarely see the track.
08-06-2018, 05:35 PM
#19
Some engines make 400 ft/lbs off idle 
Add a cam/headers and it would
https://www.corvetteactioncenter.com...curve/cat/6058
Add a cam/headers and it wouldhttps://www.corvetteactioncenter.com...curve/cat/6058
You make 400ftlbs at idle?....No. No one's arguing how it drives once you're in gear. It's about how smoothly it engages from a stop in all conditions.
It's been well proven that a relatively heavy car (most fbody owners aren't into major weight reduction) combined with a light flywheel/clutch setup do not drive like stock. Plenty claim theirs "drives like stock", but there's a reason race shops don't recommend a lightweight combo for true street cars that rarely see the track.
It's been well proven that a relatively heavy car (most fbody owners aren't into major weight reduction) combined with a light flywheel/clutch setup do not drive like stock. Plenty claim theirs "drives like stock", but there's a reason race shops don't recommend a lightweight combo for true street cars that rarely see the track.
08-06-2018, 05:47 PM
#20
Some engines make 400 ft/lbs off idle Add a cam/headers and it would
https://www.corvetteactioncenter.com...curve/cat/6058
Add a cam/headers and it wouldhttps://www.corvetteactioncenter.com...curve/cat/6058
Last edited by ddnspider; 08-06-2018 at 06:33 PM.