Clutches.
Clutches.
Okay im asking the question I asked before (again)...
Im still shopping for a clutch. My question is, Which clutch to get? Do all clutches come with a pressure plate? a.k.a. does the KYclutch come with a pressure plate? is a new pressure plate necessary?
Do I need an aftermarket Flywheel? Does an aftermarket flywheel make the car less reliable? I notice the Exedy hypersingle come with a flywheel. Does that clutch kit work with the LNF?
I heard bad stuff about spec clutches so im pretty much turned off from those, but they seem cheap and include an alignment tool and a clutch pressure plate.
What stage clutch should I get? Which would be best for some dragstrip use and street diveable at say... 350trq and 330whp? If I want to make more power than what I am making (300whp and 330trq), what clutch would be a good compromise? Im thinking the most HP and torque i'd want to make would be 350whp and 400trq. Im not sure about a turbo swap yet, but I will probably require a new clutch when that time comes as well, lol.
Lots of questions... I know I just watched some videos on how they work and have a better understanding of them. It seems that a new flywheel would be pointless right? And the stiffness of the clutch comes from a combination of the master cylinder and the pressure plate correct?
Im still shopping for a clutch. My question is, Which clutch to get? Do all clutches come with a pressure plate? a.k.a. does the KYclutch come with a pressure plate? is a new pressure plate necessary?
Do I need an aftermarket Flywheel? Does an aftermarket flywheel make the car less reliable? I notice the Exedy hypersingle come with a flywheel. Does that clutch kit work with the LNF?
I heard bad stuff about spec clutches so im pretty much turned off from those, but they seem cheap and include an alignment tool and a clutch pressure plate.
What stage clutch should I get? Which would be best for some dragstrip use and street diveable at say... 350trq and 330whp? If I want to make more power than what I am making (300whp and 330trq), what clutch would be a good compromise? Im thinking the most HP and torque i'd want to make would be 350whp and 400trq. Im not sure about a turbo swap yet, but I will probably require a new clutch when that time comes as well, lol.
Lots of questions... I know I just watched some videos on how they work and have a better understanding of them. It seems that a new flywheel would be pointless right? And the stiffness of the clutch comes from a combination of the master cylinder and the pressure plate correct?
gotcha okay, Ive been leaning towards KYclutches the wholre time. I wasnt sure if it came with a pressure plate, alignment tool etc. resurfacing the flywheel is pretty much the consensus here.
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Joined: 05-18-05
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From: Boston & SoCal
Clutches are rated for their torque holding ability and not horsepower (at least reputable manufacturers should not be rating in horsepower alone). Also not every "Stage" clutch is going to be the same. It's essentially just an overused label that may only be valid for comparisons between one manufacturer's product line. The industry standard, and using the term standard very loosely is that a Stage 1 or 2 is pretty close to stock replacement, most Stage 3 clutches still use some sort of organic-based disc (carbon Kevlar, etc.), while Stage 4 clutches are generally the ceramic puck-type discs.
Some newer cars use a modular clutch assembly which is essentially a one piece flywheel/clutch disc/pressure plate assembly all bolted or riveted together that bolts to a flex plate connected to the crank (similar to how the torque converter on a conventional automatic transmission bolts to a flex plate). There are also some vehicles that use a dual-mass flywheel assembly that has the flywheel split into two pieces connected via large springs around the circumference that helps to absorb driveline shock. Both of those types of clutches generally can't be serviced, meaning if the clutch is end of life you can't surface the flywheel and install a new disc and pressure plate.
Luckily the F35 transaxle in the SS Turbo and older cars uses a conventional flywheel and clutch assembly. It has a regular flywheel that bolts directly to the crank and then the pressure plate bolts to the flywheel with the disc installed between the two. If the car had very low miles and no signs of wear or bluing (caused by slippage and/or overheating) and you're upgrading you might be able to get away with reusing a pressure plate and flywheel with a new disc but it is usually not recommended. At the very least you'd want to rough up the surface slightly. Even then, if there are deposits on either surface the new disc may not seat and break in properly. Therefore it's generally recommended to either replace or resurface the flywheel and install a new pressure plate when you change a clutch.
Some clutch companies will sell a "kit" that includes a new pressure plate, disc, and usually a throw-out (release) bearing for a car but assume you'll either surface or replace the flywheel on your own. Others will offer a full replacement set that comes with their own flywheel. This is usually some sort of lightened steel or aluminum (with steel insert) and/or SFI-certified flywheel that is approved for certain racing series.
Clutch pedal feel is mostly going to be determined by the pressure plate and more specifically if the diaphragm fingers are stiffer and apply more clamping force to hold the disc against the flywheel. This will generally increase the torque holding capacity but result in a stiffer pedal feel as it takes more force to disengage the clutch. Some clutch manufacturers also modify the pivot point of the diaphragm fingers which can result in a different engagement point.
Pressure plates with higher clamping loads might sound good but they also place more side loading on the thrust bearing that holds the crankshaft in place and locates it side-to-side. If that bearing is susceptible to premature wear the engine could develop "crank walk" where the thrust bearing has worn and the crank has excessive movement. For a daily driven car that's one reason why you don't want to go overboard and think that a higher clamping force (i.e. pressure plate strength) is always better. If you don't need it or can find another clutch disc that offers similar torque handling abilities without as much clamping pressure (due to the actual frictional material itself) it can reduce long-term wear on the engine.
Speaking of the pressure plate, some "performance" clutch builders make their own pressure plates but many cases you'll find others just re-use or brand an OEM plate (usually Sachs, LuK, or Exedy for a lot of newer domestic cars) as their own. Sometimes they'll modify the pivot point of the fingers. Occasionally they'll replace the diaphragm fingers. And sometimes they'll just painting it and calling it good enough. If you're buying from a smaller, specialized clutch company there's a greater chance they'll reuse a new factory type pressure plate so make sure to ask them if they're doing that and if so what they've done (if anything) to modify it. If they have altered it ask to see what the stock clamping force was and what the modified pressure plate is rated at.
As an example, say the stock pressure plate is rated at 2200 psi clamping force and they've modified it so that it produces 2400 psi force. That might not be an issue, but if they've modified it or have their own pressure plate design that is rated at 3200 psi that would be a significant bump and might not be good for a daily driven car down the road.
Some newer cars use a modular clutch assembly which is essentially a one piece flywheel/clutch disc/pressure plate assembly all bolted or riveted together that bolts to a flex plate connected to the crank (similar to how the torque converter on a conventional automatic transmission bolts to a flex plate). There are also some vehicles that use a dual-mass flywheel assembly that has the flywheel split into two pieces connected via large springs around the circumference that helps to absorb driveline shock. Both of those types of clutches generally can't be serviced, meaning if the clutch is end of life you can't surface the flywheel and install a new disc and pressure plate.
Luckily the F35 transaxle in the SS Turbo and older cars uses a conventional flywheel and clutch assembly. It has a regular flywheel that bolts directly to the crank and then the pressure plate bolts to the flywheel with the disc installed between the two. If the car had very low miles and no signs of wear or bluing (caused by slippage and/or overheating) and you're upgrading you might be able to get away with reusing a pressure plate and flywheel with a new disc but it is usually not recommended. At the very least you'd want to rough up the surface slightly. Even then, if there are deposits on either surface the new disc may not seat and break in properly. Therefore it's generally recommended to either replace or resurface the flywheel and install a new pressure plate when you change a clutch.
Some clutch companies will sell a "kit" that includes a new pressure plate, disc, and usually a throw-out (release) bearing for a car but assume you'll either surface or replace the flywheel on your own. Others will offer a full replacement set that comes with their own flywheel. This is usually some sort of lightened steel or aluminum (with steel insert) and/or SFI-certified flywheel that is approved for certain racing series.
Clutch pedal feel is mostly going to be determined by the pressure plate and more specifically if the diaphragm fingers are stiffer and apply more clamping force to hold the disc against the flywheel. This will generally increase the torque holding capacity but result in a stiffer pedal feel as it takes more force to disengage the clutch. Some clutch manufacturers also modify the pivot point of the diaphragm fingers which can result in a different engagement point.
Pressure plates with higher clamping loads might sound good but they also place more side loading on the thrust bearing that holds the crankshaft in place and locates it side-to-side. If that bearing is susceptible to premature wear the engine could develop "crank walk" where the thrust bearing has worn and the crank has excessive movement. For a daily driven car that's one reason why you don't want to go overboard and think that a higher clamping force (i.e. pressure plate strength) is always better. If you don't need it or can find another clutch disc that offers similar torque handling abilities without as much clamping pressure (due to the actual frictional material itself) it can reduce long-term wear on the engine.
Speaking of the pressure plate, some "performance" clutch builders make their own pressure plates but many cases you'll find others just re-use or brand an OEM plate (usually Sachs, LuK, or Exedy for a lot of newer domestic cars) as their own. Sometimes they'll modify the pivot point of the fingers. Occasionally they'll replace the diaphragm fingers. And sometimes they'll just painting it and calling it good enough. If you're buying from a smaller, specialized clutch company there's a greater chance they'll reuse a new factory type pressure plate so make sure to ask them if they're doing that and if so what they've done (if anything) to modify it. If they have altered it ask to see what the stock clamping force was and what the modified pressure plate is rated at.
As an example, say the stock pressure plate is rated at 2200 psi clamping force and they've modified it so that it produces 2400 psi force. That might not be an issue, but if they've modified it or have their own pressure plate design that is rated at 3200 psi that would be a significant bump and might not be good for a daily driven car down the road.
Last edited by blackbird; Jun 2, 2011 at 05:45 AM. Reason: speeling fixored
okay, THat is some good info there 
So it sounds like the ideal thing to do when buying a new clutch is to buy a factory flywheel along with it. Nobody sells flywheels with there clutch as a kit and I hear too many horror stories with lightweight flywheels. im not sure I want one of those. Rigidity of lightweight flywheels is reduced in order to drop 10Ibs of rotational mass... Stock flywheels look like they are cheap to purchase too.
When I order from KYclutches, I will ask what brand pressure plate it is and if they modified it and how. I will also purchase a new stock flywheel.
So it sounds like the ideal thing to do when buying a new clutch is to buy a factory flywheel along with it. Nobody sells flywheels with there clutch as a kit and I hear too many horror stories with lightweight flywheels. im not sure I want one of those. Rigidity of lightweight flywheels is reduced in order to drop 10Ibs of rotational mass... Stock flywheels look like they are cheap to purchase too.
When I order from KYclutches, I will ask what brand pressure plate it is and if they modified it and how. I will also purchase a new stock flywheel.
Senior Member
Joined: 05-18-05
Posts: 1,070
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From: Boston & SoCal
The GM engineers supposedly downsized the flywheel used on the LNF cars in order to fit a larger clutch. As such it doesn't sound like it is shared with other applications and was fairly expensive the last time I checked. You're probably better off checking with a local machine shop about getting your current flywheel surfaces (if necessary). Most good machine shops should be able to check the specifications, check your flywheel, and then remove material if needed and in the correct area (e.g. stepping).
What type of horror stories are you hearing about lightened flywheels? I'd say I hear way more stories about clutch durability issues, drivability due to selecting an inappropriate clutch for the application and so on. In general a slightly lighter steel clutch than stock shouldn't change the way the engine revs significantly. Most aluminum flywheels with steel friction inserts are going to weigh quite a bit less than a factory iron or steel flywheel, and they may allow the engine to rev quicker and be slightly more difficult to launch, but again I know many people who have bought ceramic four and six-puck discs that don't work very well and cause way more on-off type drivability issues.
What type of horror stories are you hearing about lightened flywheels? I'd say I hear way more stories about clutch durability issues, drivability due to selecting an inappropriate clutch for the application and so on. In general a slightly lighter steel clutch than stock shouldn't change the way the engine revs significantly. Most aluminum flywheels with steel friction inserts are going to weigh quite a bit less than a factory iron or steel flywheel, and they may allow the engine to rev quicker and be slightly more difficult to launch, but again I know many people who have bought ceramic four and six-puck discs that don't work very well and cause way more on-off type drivability issues.
The SPEC Stage 2+ and matching lightweight FW I drove for 40k miles worked together well. Only issue I had with the SPEC was it moaned a bit on the first few engages when cold.
As Blackbird said, it revved a bit quicker and was a bit harder to DD until I got used to it.
I know you don't like SPEC though.
As Blackbird said, it revved a bit quicker and was a bit harder to DD until I got used to it.
I know you don't like SPEC though.
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Joined: 09-04-09
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From: Alabama
I have a Spec 3+ and LW FW, but if I wouldn't have gotten the set for the cost of the clutch by itself (forum member) I would have went with Ky clutch.
As a matter of fact if my Spec dies for some reason I will be resurfacing my factory FW and getting a Ky clutch.
Id rather blow through $380 clutch's then a $600 clutch's, that my opinion.
As a matter of fact if my Spec dies for some reason I will be resurfacing my factory FW and getting a Ky clutch.
Id rather blow through $380 clutch's then a $600 clutch's, that my opinion.
Senior Member
Joined: 06-22-09
Posts: 5,989
Likes: 7
From: Kathmandu
I have a Spec 3+ and LW FW, but if I wouldn't have gotten the set for the cost of the clutch by itself (forum member) I would have went with Ky clutch.
As a matter of fact if my Spec dies for some reason I will be resurfacing my factory FW and getting a Ky clutch.
Id rather blow through $380 clutch's then a $600 clutch's, that my opinion.
As a matter of fact if my Spec dies for some reason I will be resurfacing my factory FW and getting a Ky clutch.
Id rather blow through $380 clutch's then a $600 clutch's, that my opinion.
Member
Joined: 10-19-09
Posts: 214
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From: Milton, FL
This question has been asked about 100x times on this board. The answer is always the same.
Exedy is great quality but out of their effin minds on price..
Spec clutches have had enough bad reviews to turn away most people, a good deal of good reviews as well...
zzp has graet clutches but a little high on price as well
ky is priced well and minus some bleeding issues which I believe are backyard mechanics faults, hold well, priced well, and work well.
I am installing my ky TODAY. I hope I made the right choice after reading all these threads. I believe I have though.
Exedy is great quality but out of their effin minds on price..
Spec clutches have had enough bad reviews to turn away most people, a good deal of good reviews as well...
zzp has graet clutches but a little high on price as well
ky is priced well and minus some bleeding issues which I believe are backyard mechanics faults, hold well, priced well, and work well.
I am installing my ky TODAY. I hope I made the right choice after reading all these threads. I believe I have though.
Senior Member
Joined: 06-22-09
Posts: 5,989
Likes: 7
From: Kathmandu
Seriously. Pointers, instructions, pics, would be super-helpful. Do you have to drop the subframe? If you do, do you separate the rack from the frame or another way? How do you bleed the new TOB/slave?
Edit: Oh crap, I just realized you have an HHR, hence the username.
Edit: Oh crap, I just realized you have an HHR, hence the username.
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Joined: 09-04-09
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From: Alabama
I used jack stands and did it by myself following the LSJ removal/install guide (minus the wife holding the brake to break free/torque the axle nut and clutch bleeding).
Use the LNF torque specs.
I installed a Spec 3+ clutch and Spec lightweight flywheel in my HHR SS.
I used jack stands and did it by myself following the LSJ install (minus the wife holding the brake to break free/torque the axle nut and clutch bleeding).
* We (LNF) do not need a E10 torx bit (in LSJ guide)
* We (LNF) also don't need a 30mm axle nut socket (in LSJ guide), we need a 36mm.
(at least the HHR SS did)
Last edited by HHRSSouth; Jun 1, 2011 at 04:21 PM.
another member from here (kyle4236) had a ky clutch put in about a month and a half ago and now needs a new clutch. Aparently the new throw out bearing took a deuce and the clutch wasn't disengaging because of it and the whole clutch is f#cked because of it. Obviously wasn't a bad clutch but still blows. After he paid for the ky and to have it installed he took it to the dealer and they are saying that he needs a new clutch and he has to pay like $1400 to get his car fixed so he can pick it up
another member from here (kyle4236) had a ky clutch put in about a month and a half ago and now needs a new clutch. Aparently the new throw out bearing took a deuce and the clutch wasn't disengaging because of it and the whole clutch is f#cked because of it. Obviously wasn't a bad clutch but still blows. After he paid for the ky and to have it installed he took it to the dealer and they are saying that he needs a new clutch and he has to pay like $1400 to get his car fixed so he can pick it up
$1400 is crazy just to get it up and runnin'
The removal/install of the transmission is the same for the HHR SS, Cobalt SS/TC, Cobalt SS/SC
I used jack stands and did it by myself following the LSJ removal/install guide (minus the wife holding the brake to break free/torque the axle nut and clutch bleeding).
Use the LNF torque specs.
I installed a Spec 3+ clutch and Spec lightweight flywheel in my HHR SS.
I used jack stands and did it by myself following the LSJ install (minus the wife holding the brake to break free/torque the axle nut and clutch bleeding).
* We (LNF) do not need a E10 torx bit (in LSJ guide)
* We (LNF) also don't need a 30mm axle nut socket (in LSJ guide), we need a 36mm.
(at least the HHR SS did)
I used jack stands and did it by myself following the LSJ removal/install guide (minus the wife holding the brake to break free/torque the axle nut and clutch bleeding).
Use the LNF torque specs.
I installed a Spec 3+ clutch and Spec lightweight flywheel in my HHR SS.
I used jack stands and did it by myself following the LSJ install (minus the wife holding the brake to break free/torque the axle nut and clutch bleeding).
* We (LNF) do not need a E10 torx bit (in LSJ guide)
* We (LNF) also don't need a 30mm axle nut socket (in LSJ guide), we need a 36mm.
(at least the HHR SS did)
I purchased a stock ss/tc clutch, throwout bearing, alignment tool, and a clutchmasters aluminum flywheel awhile back. Since that purchase I decided to add a decent amount of power to the car so the stock clutch idea got scraped. I tried getting a Spec Stage 3+ but Spec didn't want me using that clutch with a Clutchmaster or Stock flywheel for whatever reason. I ended up going with a Clutchmaster stage 4 6 puck clutch which should get here tomorrow.
The SPEC clutches are set up for their own flywheels. If you want to reuse the stock LNF FW, the dowel holes have to be bored out to 12mm to accept the SPEC Pressure Plate dowels. At least that was the case a year ago. Some have not used the dowel pins at all without issue but I would not recommend it.
Yes, I recall reading this somewhere. Thing is..I don't understand it! If the clutch on the TC was made *larger* (than previous ss/sc), why was the flywheel DOWNSIZED?