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Old 08-31-2010, 01:02 PM   #126
ACTman
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Quote:
Originally Posted by bcjp11 View Post
Obviously not a clutch expert so seeking feedback and opinions from more experienced minds.

I read the warning about buying too much clutch. However, is it mechanically acceptable to buy too much clutch with the idea that your car will "grow" into the clutch?

I have my motor and tranny out and I am replacing the clutch. I am going to go with a higher HP setup next Spring. I don't want to redo the clutch work only six months down the road.

Thanks.
Too much clutch and you can potentially damage parts that you may not if you have "just enough" clutch. By far the biggest influence on how fast you break parts has less to do with the clutch and more to do with the driver. Holding more torque than what the engine needs is only a problem if you are putting a lot more torque through the clutch than the engine produces. This is done by introducing a lot of inerita... In other words - dropping the clutch at high rpm, super aggressive downshifts, WOT shifting, etc.

Also torque capacity is not as much of an issue as clutch design, IMO. Having a race type clutch with aggressive friction material is going to be harsher engaging so you give up drivability when you may not need to, and it has more instant engagement. A solid center disc will transfer more torsional vibration than a spring center disc, cause rapid spline wear on the disc, increased gear noise and even more instant engagement. I hope that helps.
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Old 08-31-2010, 04:43 PM   #127
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Quote:
Originally Posted by ACTman View Post
Too much clutch and you can potentially damage parts that you may not if you have "just enough" clutch. By far the biggest influence on how fast you break parts has less to do with the clutch and more to do with the driver. Holding more torque than what the engine needs is only a problem if you are putting a lot more torque through the clutch than the engine produces. This is done by introducing a lot of inerita... In other words - dropping the clutch at high rpm, super aggressive downshifts, WOT shifting, etc.

Also torque capacity is not as much of an issue as clutch design, IMO. Having a race type clutch with aggressive friction material is going to be harsher engaging so you give up drivability when you may not need to, and it has more instant engagement. A solid center disc will transfer more torsional vibration than a spring center disc, cause rapid spline wear on the disc, increased gear noise and even more instant engagement. I hope that helps.
From what I gather, if I overbuy on a clutch now, "grow" into it with a turbo upgrade in the Spring, and I don't look for red light racing in the city, then I should be great until Spring.

I read that if you go with Spring Clutch design, it will be less harsh on the driveline and more importantly, a twin plate is better than a harsh six puck.

Again, just regurgitating what I have read so please correct me.
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Old 08-31-2010, 05:24 PM   #128
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Originally Posted by bcjp11 View Post
From what I gather, if I overbuy on a clutch now, "grow" into it with a turbo upgrade in the Spring, and I don't look for red light racing in the city, then I should be great until Spring.

I read that if you go with Spring Clutch design, it will be less harsh on the driveline and more importantly, a twin plate is better than a harsh six puck.

Again, just regurgitating what I have read so please correct me.
The typical twin plate also uses cerametallic friction materials so it will just as harsh as a six puck (only more expensive) with the advantage of less pedal effort, and possibly more durability (heat capacity).
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Old 10-16-2010, 09:33 AM   #129
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The fastest Subarus in the world use those multiplate clutches, and they last for one event, and are replaced. They are also approximately $1000 and up for a "weekend warrior" clutch... if you are headed for Nurburgring, $5000 for a days fun...

I just got a kit from ACT that offers a great warranty on top of a few performance features that made them more enticing than Subaru.
Also, it was the exact price of the original equipment/OE parts from SOA.

Lightened flywheel is computer designed and weighted to determine maximum loss of mass before misfire, with a good margin for those of us with pulley sets.

I have a RalcoRZ 3 pulley kit, no issues, excellent machine work, lighter and faster throttle... that's what sent me shopping for the clutch... our OEM Exedy Organic clutch heats too fast for me, due to it's small surfaces. My forward bearing is shot also. Might has well do it all at once...

The clutch is an ACT SB3 HDSS/Streetlite Solid Flywheel. It's not much more than stock, but a stiffer pedal would be nice. It's sprung, and should be a lot quieter than the one I've got... it's dissolving, I can feel it melting away.

The flywheel is about 4lbs lighter than stock. Not enough to create an issue, but combined with pulleys, it will be nice.

The CEL worry is a misnomer, at least on pulleys...

Have you looked at your pulleys up close? Taken out your clutch and flywheel? Yuck, y'all...

It's Nasty.

All that corrosion (I've got an '02 Sedan ProDrive, it's got some ugly in it)
makes for some bad balance. There's enough that if you turn one on a single-sensor scale, it will throw the reading. All of them together make for a crankshaft that dances around, hauled in every direction by the little "weights" made from chipped metal and rust on them. Precision lightweight pulleys of stock diameter will not throw a CEL code. If anything, they'll prevent it, along with belt wear.

The flywheel is similar. A one piece forged chromoly flywheel is more precise, less likely to warp from heat, and will withstand higher clamping loads without failure. Cleanliness is next to the trophy case, right? If you want to get an old daily driver to stop beating your eardrums, sometimes pulleys and flywheel are number one.

I'll have the clutch done on Wednesday, and I'll let you know what happens.
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Old 11-11-2010, 12:18 AM   #130
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Thanks for this thread! I keep hearing from other members that some of these clutch kits are "rebuild-able"

what exactly are they referring to? I can purchase a new clutch disk to go with the pressure plate from the kit? Do i send the disk back to the mfg to have the rebuild it...?

Or do i need to purchase a new kit based on the condition of the pressure plate, disk, and so forth?
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Old 11-11-2010, 01:58 PM   #131
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How long, if at all is a new clutch suppose to slip during 500 mile break in? I have 200 miles of NO boost driving on oem exedy replacement on a lightened f1 racing flywheel. Any input would greatly be appreciated for some reason I think it's a defective clutch
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Old 01-12-2011, 09:50 PM   #132
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Thank you for saving me money on a clutch and explaining why I get the error code all of the time.
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Old 01-29-2011, 12:32 AM   #133
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Quote:
Originally Posted by blue03_wrx View Post
How long, if at all is a new clutch suppose to slip during 500 mile break in? I have 200 miles of NO boost driving on oem exedy replacement on a lightened f1 racing flywheel. Any input would greatly be appreciated for some reason I think it's a defective clutch
You possibly need clutch pedal adjusted. When I replaced my clutch with a 6-puck, I had the same thing and thought that harshness was overrated. Then I realized the clutch was not grabbing fully. When I adjusted clutch pedal rod, I realized what "harsh" mean. And the slip was gone too. Make sure you have a little play in the pedal. If the pedal being up top is still preloaded (no free play), that means it's still holding the pressure plate and not letting it to grab fully, wearing out the throwout bearing too.


PS: To all talking about decel noise... Wait until you do like I did:
GroupN mounts, Streetlite flywheel, Clutchmasters FX-400 (6-puck), and of course Unabombers Sexy Rearend (No! I'm not gay ) which consists of race differential bushings, outrigger bushings and lock bolts.
When you experience this combination then start talking about deceleration noise, and this is still far from maximum... A lot of times I wish I didn't go that hard, but then I do like the performance and tightness of the car... Your choice.
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Old 02-10-2011, 11:21 AM   #134
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About a year ago I replaced my stock clutch with an ACT HD, 6 Puck Sprung, StreetLite FW. My current setup is with an AVO 380, Single cat DP, AVO TMIC, K&N Typhoon Intake. My power levels are around 350HP/320TQ. I don't dump the clutch and I don't race, I do however like driving quickly. The ACT only lasted a year and it's rated for 4--TQ if I remember right.
Needless to say I'm looking at a new clutch already, just wondering what all the Subie pros on here thought of going with a twin plate system. I was looking at the Carbonetic Twin Clutch. Anyone have input on that or the exedy?
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Old 02-22-2011, 02:57 PM   #135
Slim1721
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man i wish i would have looked at this before i put in my lightened flywheel, its been a pita to get my CEL to stay out for emmissions
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Old 03-04-2011, 10:53 AM   #136
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Default Stock '97 Impreza L 2.2 needing clutch and tranny info.

Completely factory stock driveline and may keep it that way.

Tranny now in car was a junkyard unit of unspecified miles put in January '05 at a Subaru dealer when my old one went bad at 100,000 miles.

Now I'm at 197K. This one is doing the same thing that one did: No noise when in gear, clutch in. Idling, in neutral, clutch out, the bearings rattle and howl noticably. (Input shaft bearings?) Then, when I drive it, it has horrendous gear whine in all gears when you apply any gas. When you lift, the gear whine disappears. I'm looking for a stock used tranny with the 3.90 diff and 1:1 transfer gears. I'm going to check with a photo tachometer while my side wheels are elevated to see which gears I have in this tranny for 2ND, 3rd, and 4th. I'll compare engine speed to wheel speed realizing wheel speed in this case will be double the diff speed. I saw the tranny chart. It SEEMS '96 -'01 2.2 cable clutch trannys will work. Mine has the cable drive speedo, too. Is it possible to easily use an electric drive speedo tranny in a cable drive car?

Clutch question: If I change to a different cable actuated 5MT AWD tranny with a 3.90 diff '96-'01, will I have to change any clutch pieces from my stock '97 spec? I'm using all factory parts now AND in the future.
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Old 04-13-2011, 11:21 PM   #137
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so i know that no one reccomends that you use one brand of clutch disc with another brands pressure plate, but what about one matching clutch kit with another brand of flywheel? does anyone have experience with this setup and what are the ill-effects if any?
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Old 04-14-2011, 12:08 AM   #138
ACTman
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With the Subie, you should be ok to swap to a different brand flywheel without compatability problems. Of course that doesn't mean that all flywheels are created equal.
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Old 04-14-2011, 01:11 PM   #139
TCL1999
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Default Clutch Questions

Ok, so I looked through the FAQ and didn't see the Qs or As that I was looking for, so I'm going to ask them:

Are Subie motors internally balanced? In other words, do flywheels not require any balancing before placing them on the motors? The reason I ask is because I'm looking to replace the OEM flywheel with a stock replacement and in my previous non-subie experience, my engines have been externally balanced between the harmonic balancer and flywheel. I figure the flat-4 configuration lends itself to being internally balanced, I just want to make sure.

Also, do the flywheel bolts line up such that the flywheel will only mount to the motor in one position?

And finally, since it looks like dropping the tranny is a PITA, if I'm going to do a timing belt change at the same time, would it be easier to just yank to motor, change the belt and clutch at the same time and leave the tranny where it sits?

Thanks!
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Old 04-14-2011, 01:29 PM   #140
ACTman
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Originally Posted by TCL1999 View Post
Ok, so I looked through the FAQ and didn't see the Qs or As that I was looking for, so I'm going to ask them:

Are Subie motors internally balanced? In other words, do flywheels not require any balancing before placing them on the motors? The reason I ask is because I'm looking to replace the OEM flywheel with a stock replacement and in my previous non-subie experience, my engines have been externally balanced between the harmonic balancer and flywheel. I figure the flat-4 configuration lends itself to being internally balanced, I just want to make sure.

Also, do the flywheel bolts line up such that the flywheel will only mount to the motor in one position?

And finally, since it looks like dropping the tranny is a PITA, if I'm going to do a timing belt change at the same time, would it be easier to just yank to motor, change the belt and clutch at the same time and leave the tranny where it sits?

Thanks!
The flywheels are neutral balance for the Subie and have a symetrical bolt pattern. Years ago auto makers had not only the components balanced (internal balancing), but went on to balancing the assembly by taking a small amount from the balancer or flywheel to fine-tune balance the engine, but most automakers have moved away from that method and just balance the components.

With an opposed four cylinder engine it is pretty safe to assume the engine is going to be internally balanced since the crank throws are opposite eachother and the counterweights are easy to position internally. Of course some engines are designed with external balancing and the flywheel will only bolt on in one position, etc (not the Subie).
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Old 04-14-2011, 01:34 PM   #141
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That's kinda what I figured, but thanks for the confirmation. Has anyone else had trouble finding OEM replacement flywheels (without getting abused by the local dealership) or is it just me?
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Old 04-14-2011, 03:46 PM   #142
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Can anyone tell me what the difference is between the 2002 wrx flywheel and the 2002 impreza flywheel? Everywhere I look (including dealerships) says the wrx flywheel is different from the impreza's, and most say the wrx flywheel is discontinued. Why would Subaru discontinue only the wrx flywheel?

Nevermind...I am finding stuff on the judder issue and service bulletin. Looks like maybe Subaru changed something midway through 2002 because of the judder? Anyway, I'll look for part numbers associated with the fix.

Last edited by TCL1999; 04-14-2011 at 04:49 PM.
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Old 04-14-2011, 09:14 PM   #143
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IMHO pulling the trans is much more difficult than pulling out the engine, assuming you have an engine hoist if not you may not have a choice. i will be doing my clutch soon and plan on doing a detailed write up along with it since i will be pulling the engine and at the same time replacing the timing belt/pulleys, seals and gaskets and motor mounts. Subaru engines are mounted with 2 motor mounts and the rear pitch stop so one you remove those its only a matter of wires and accessories to get out of the way.
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Old 04-25-2011, 03:52 PM   #144
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ive been looking for days can anybody tell me what power level the stock clutch is good for in an 08 wrx?
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Old 05-01-2011, 10:17 PM   #145
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Default TY Unabomber

Thanks Unabomber for starting this thread, it has a boatload of useful info. Before reading this complete thread I was going to use an Exedy clutch kit on my hybrid build. After reading about all the transmission noise issues when using a non-OEM friction plate and/or a lighter flywheel I have decided on the following - stock flywheel with an RPS Turboclutch (for me it's an MS-20WRX-ST). This setup uses an OEM friction plate and their patented pressure plate which delivers much more clamping pressure. This combo (should) avoid any amplified transmission noise (stock flywheel and friction plate) and is supposed to be good for up to 400 fp tq at the flywheel, fwiw the STI kit is rated for up to 475 tq. I'll be done in about a month and will check back in and let you know the results.
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Old 05-20-2011, 06:33 PM   #146
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At 118,000 miles, plus the super awesome shudder ,I figured it's time to replace my clutch. After MUCH reading I have decided it's in my and my cars best interest to stick with the OEM setup. Question is, if I call up my Nasioc approved local dealer and request a clutch kit and flywheel for an 02 Wrx am I going to get the newer updated parts that solved(hopefully) the shudder issues?

I've read using 05 stuff worked great. Please help, just can't sift through anymore threads.


Thanks
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Old 07-25-2011, 01:13 AM   #147
David964
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Default Thank you for posting this awesome Sticky!


Thank you very much for posting this information, you've probably helped hundreds of thousands, and now +1 for me!

I'm thinking of getting a new clutch and this shed light where light use to not be shed! Great work and know that it's very much appreciated!
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Old 07-25-2011, 07:35 AM   #148
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Quote:
Originally Posted by skip4343 View Post
At 118,000 miles, plus the super awesome shudder ,I figured it's time to replace my clutch. After MUCH reading I have decided it's in my and my cars best interest to stick with the OEM setup. Question is, if I call up my Nasioc approved local dealer and request a clutch kit and flywheel for an 02 Wrx am I going to get the newer updated parts that solved(hopefully) the shudder issues?

I've read using 05 stuff worked great. Please help, just can't sift through anymore threads.


Thanks
A dealer, using your VIN number will know if the judder TSB was applied to your car. In time, TSB parts superceed the initial parts, so you will get the updated parts.
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Old 08-03-2011, 11:40 PM   #149
King solomon
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I bought a 1999 2.5 rs with a light weight flywheel already installed which is awesome, however it throughs a code for a misfire. So to take care of it, im going to reinstall the stock flywheel and i figure i might as well replace the clutch while im there, since it has almost 70,000 miles on it. the only problem is i dont know what to get. i was looking at the exedy OEM replacement clutch kit, and the F1 stage 1 clutch kit, and the XTR racing stage 1 performance street clutck kit. Has anyone heard anything good or bad about these kits? your suggestions are appreciated.
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Old 08-22-2011, 09:21 PM   #150
05subiegtwagon
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This might be a dumb question will a 05 wrx flywheel fit on a 05 LGT and if so will it work good and have any improvement. Thanks for any help
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