Corvette Performance - Input on clutches...

Meh. 98 corvette coupe.

I have searched...I have spoken with many experts...and still I am like :confused: :confused: :confused: :confused: when it comes to making a decision :jest:

I need to revamp my clutch. Not so much the clutch but the hydraulics. I am SO FREAKING SICK of the pedal sticking to the floor. It's probably the slave/master + the fact that the lines get so hot and burn the fluid so fast...but since I have 72k miles I am just going to do everything at one time.

Just normal driving, it sticks. I was trying to merge into fast traffic today, shifted second and lifted off the pedal, it stuck, then finally caught and the tires chirped as traction control came on :eyes: It's kind of dangerous.

I change the fluid every 3-4 days and keep it super clean but now it's just getting worse. I drive the car to work every day so I can't really live with this problem much longer.

I'm going to stay with a stock-esque clutch. For one thing I love this car as-is, and won't do more to it besides a couple of bolt ons. Money doesn't really permit a huge blower anyway :( And since I'll be moving next year, the light bolt on stage is going to be a rather permanent one for my car.

With that being said I don't want a fancy, expensive 600hp clutch. I am going between the Ls7 and LS6 setups, with new LS6 master & slave, brass pilot bushing, and a new throwout bearing (anyone got the GM part # for the throwout?)

I'm confused on the flywheel. I was thinking of going to a lighter one but damn I hear 50/50 comments either way. My #1 job for this car is to be a daily driver. Then auto crossing, then the occasional (no more than once a month) drag racing on street tires. Thoughts?? I know I can just resurface my stock one, but I don't really want to. If I go LS7 I'd have to get a new flywheel anyway, and if I go Ls6 clutch I want to try the AL i think...

:confused: :engarde: :confused: :engarde:

If you're doing a clutch, do a Centerforce Dual Friction - for the price, you win and it holds decently. They drive like stock because of the throw out weights on them and they hold decently well. Just my opinion, but definately grab some 2004 z06 hydraulics...

whatever you do DO NOT use a centerforce, I've tried them in the past and they are absolute crap on our cars, biggest waist of time and $$ in my life, everybody that told me how great they were never had experience with them...... ........... .......................... but now I know.. (also, the throw out weights put too much pressure on the slave when trying to disengage..)

seeing as how you dont want to spend much $$, your plan you have now is pretty good, I've resurfaced flywheels in the past and its great, only cost 40bucks, so if your going to go w/ a stock flywheel I say resurface the one you have now and grab an ls6 pressure plate and disc, slave, master, seals, ect... I wouldnt go aluminum flywheel if your in heavy traffic daily....

I'm using a McLeod twin disc w/steel flywheel, McLeod master and ls6 slave... handles 5kdumps all day long... I auto-x w/slicks alot, and also my daily driver...... the absolute best clutch for our cars.!

a buddy of mine with a GTO just put a ls7 in its not the best cluch but better then his stocker for sure... i just ordered a textralia clutch with new hydraulics for my frc. a guy i know with a 427 has it and it drives so smooth. my stock clutch is hurting bad went 12.84@ 109.97 stock and then at etown last weekend went 13.2 @109 in the 100 degree heat then smoked the clutch on the second run with coolant temps of over 240 and oil temps like 235... was freaking HOT.

Why is this even up for debate? You need a clutch that handles a bit more power than the current setup, and is streetable. LS7 clutch, case closed?

I would highly recommend making sure that the hydraulics are upgraded to 04 specs. Also, if you do use a LS7 clutch there are a few tips and tricks needed to install on a LS1 motor.

Chad

Keliente, don't see a description of your set-up. So I will assume your rwhp is 390 or less.

I've made 500 passes in stock C5Z06 and 33 now on the C6Z.

I can tell you that I don't recommend the LS7 clutch to anyone who plans to make passes. It's fine on the street but not at the track.

My C5Zs glazed the clutch twice in 500 passes. The C6Z glazes at least once a day at the drags. The LS7 clutch won't tolerate slip, period. The LS6 clutch will. LS7 clutch won't accept a launch rpm >3800 no matter how fast the clutch release is.

I've not met a single C6Z owner at the drags who likes the LS7 clutch.

Ranger

Sorry Ranger - no set up really. Vararam, shifter, catback, probably less than 320hp. Maybe will add headers in the future.

Sorry Ranger - no set up really. Vararam, shifter, catback, probably less than 320hp. Maybe will add headers in the future.

Then the LS6 clutch should give you good service. I'd suggest replacing all the clutch parts and related hydraulic. A remote bleeder is a nice addition and so is sheathing the hydraulic lines in KoolSox to reduce the heat load. Might want to consider a McLeod adjustable master.

But you need a very good installer to ensure you remain free of vibration.

Ranger

All I know (Mainly from Jaime (V-Series Tech)) is to stay way clear of Spec clutches. Sorry, but that's about all my clutch info.

Before I sold my 04Z06, I was having the same issue (just not nearly as bad as yours apparently) with the clutch sticking, but with mine, it was only while "getting on it." I really drove her nicely most of the time, but when I first bought it, it needed rear tires after only 18K miles, so the first owner must've really burned the crap outta the clutch, b/c most of the people I've spoken to with Z06's have had no probs with their clutches, some w/more than 70K miles on them.

Let us know what you decide, and how you like it once it's installed.

Then the LS6 clutch should give you good service. I'd suggest replacing all the clutch parts and related hydraulic. A remote bleeder is a nice addition and so it sheathing the hydraulic lines in KoolSox to reduce the heat load. Might want to consider a McLeod adjustable master.

But you need a very good installer to ensure you remain free of vibration.

Ranger

KoolSox, that's what else I was going to ask about. That's the best stuff to get? Is it like a tape or a wrap etc? I was going to do a remote bleeder also. Clutch, flywheel, pressure plate, pilot bushing (going to brass) throwout bearing, master, slave, add bleeder, add koolsox, and possibly a hardened output shaft while its all apart.

...I was having the same issue (just not nearly as bad as yours apparently) with the clutch sticking, but with mine, it was only while "getting on it." ....

To help with your pedal woes, here are three clutch fluid issue threads to review:

Clutch Pedal Woes--Fluid Impact (http://forums.corvetteforum.com/showthread.php?t=1353621)

C6Z06 Clutch Hydraulic Fluid--the Chevy Spec (http://forums.corvetteforum.com/showthread.php?t=1325077)

Clutch Pedal Woes--Fluid Changing Kit (http://forums.corvetteforum.com/showthread.php?t=1355341)

Ranger

Thanks Ranger....BTW, when you recommended a VERY GOOD INSTALLER, do you recommend, say, a dealership? I mean, how do I know it's a really knowledgable installer? What can we look for when we're searching?

I agree with Ranger on going with the ls6 clutch for your power level. OEM quality and should last some time with less than z06 power.

If you order a new slave it will come with a new throwout bearing so dont worry about the bearing part number.

On the flywheel I would stick with the stocker for everyday driving. Resurface yours or get a new GM flywheel. They can be found on ebay for $100 new.

KoolSox, that's what else I was going to ask about. That's the best stuff to get? Is it like a tape or a wrap etc?....

"KOOLSOX (http://www.koolmat.com/wire.shtml) is an impressive new double layered fiberglass sock designed to add extra protection to exposed spark plug boots and wires."

I used them to keep the heat off the clutch hydraulic lines. Cheap insurance for helping avoid pedal woes. Must be installed while you have everything apart.

Ranger

Thanks Ranger....BTW, when you recommended a VERY GOOD INSTALLER, do you recommend, say, a dealership? I mean, how do I know it's a really knowledgable installer? What can we look for when we're searching?
I highly recommend doing the install yourself. Its not that bad of a job and if you have a spare weekend you and a buddy should be able to get it done. Plus you will have the piece of mind that it was done right and will learn a few things about your car in the process.

Here is a nice write up.
http://64.81.110.163/~dope/c5_clutch_install_pics.html

Thanks Ranger....BTW, when you recommended a VERY GOOD INSTALLER, do you recommend, say, a dealership? I mean, how do I know it's a really knowledgable installer? What can we look for when we're searching?

Finding the right installer takes research. Here is my usual advice....

Four small suggestions to those facing a clutch replacement.

(1) Seach the CF and LS1tech archives (C5 Z06 and C5 Tech) for the words "clutch" AND "vibration" because there is a history of post-clutch-swap woes you need to be aware of.

(2) Choose your installer carefully. If you don't, the odds are good that you will not be happy with the results. You want a technician with a lot of (favorable) experience in swapping C5/C6 clutches.

(3) Insist that the new clutch assembly be sent to a reputable machine shop for balancing before the installation. Do this even if the installer insists it is unnecessary, "because it comes balanced by the manufacturer."

(4) Before you drop your car off for the installation, be very careful to memorize how much your shifter vibrates under various conditions.

Anyone that shrugs and ignores this advice has heighten the odds they will end up with notable drive train vibrations, originating from the clutch assembly, and they will have a bad time getting them resolved by their installer or anyone else.

Ranger

Thanks LS1 Jeff and Ranger. Good advice. Different opinions, but both good advice.

:cheers:

Finding the right installer takes research. Here is my usual advice....

Four small suggestions to those facing a clutch replacement.

(1) Seach the CF archives (C5 Z06 and C5 Tech) for the words "clutch" AND "vibration" because there is a history of post-clutch-swap woes you need to be aware of.

(2) Choose your installer carefully. If you don't, the odds are good that you will not be happy with the results. You want a technician with a lot of (favorable) experience in swapping C5/C6 clutches.

(3) Insist that the new clutch assembly be sent to a reputable machine shop for balancing before the installation. Do this even if the installer insists it is unnecessary, "because it comes balanced by the manufacturer."

(4) Before you drop your car off for the installation, be very careful to memorize how much your shifter vibrates under various conditions.

Anyone that shrugs and ignores this advice has heighten the odds they will end up with notable drive train vibrations, originating from the clutch assembly, and they will have a bad time getting them resolved by their installer or anyone else.

Ranger


This guy's the man. :devil:
I think he's the stock clutch master. like obi one.

Nice write up bro. If it wasn't for your post/experience....i'd be recommending LS7 clutchs all day....just cause it "seems" like it would be better.

Thanks for your advice.

Jamie

This guy's the man...Thanks for your advice....

Thanks for the kind words, Jamie. My advice on this and other topics tends to be from my own personal experience owning, drag racing and maintaining my Corvettes, breakage-free thus far.

Ranger

Thanks for the kind words, Jamie. My advice on this and other topics tends to be from my own personal experience owning, drag racing and maintaining my Corvettes, breakage-free thus far.

Ranger

My pleasure...

You can tell of your real experience....thats why I dig it.

Nothing better then that. We all reap the rewards. See you around.

Jamie

Nice write up bro. If it wasn't for your post/experience....i'd be recommending LS7 clutchs all day....just cause it "seems" like it would be better.

Thanks for your advice.

Jamie


Me too! :(

Ranger, while we're on the subject, I'd like to run something by you. I recently had the headers swapped on my car, and now I get a vibration from the shifter (and even from the seat bottom, it feels like) between 3500-6000rpms.

The clutch was perfect prior to the header install. Any idea why it would start doing this all of a sudden? Its an RPS with 3k miles on it. Think it might be the clutch even so?

Me too! :(

Ranger, while we're on the subject, I'd like to run something by you. I recently had the headers swapped on my car, and now I get a vibration from the shifter (and even from the seat bottom, it feels like) between 3500-6000rpms.

The clutch was perfect prior to the header install. Any idea why it would start doing this all of a sudden? Its an RPS with 3k miles on it. Think it might be the clutch even so?

Hi pakisho,

If the vibration was NOT present until immediately following a header installation, then I'd suggest returning to your installer for some help. I'd suspect a clearance issue beween the header, exhaust and frame or one or more fasteners needs to be retorqued. Finding the specific source of the offending part is best done with the car on a lift and someone in the car to raise the rpm. A pair of heavy leather gloves can help too.

Did your installer use new bolts or reuse the ones from your previous headers?

Ranger
__________________

I think that keliente would probly do her own clutch... Just from looking at her page

I think that keliente would probly do her own clutch... Just from looking at her page

It's true I do my own stuff...cams, gear installs, 12 bolt installs, I have done a few clutches before and did the one in my Z28 also...but this will be the first time I am handing over my car to a shop. We just got a new GM at our dealership and he is insanely anal about people working on their own cars, so I don't have access to a lift anymore :(

And to be honest doing a clutch on my garage floor is not really anything I feel like doing in the 100 degree heat. I know a great mechanic that I trust, who is insanely affordable. For the rate he charges I'm glad to give up the car for the weekend.

Hi pakisho,

If the vibration was NOT present until immediately following a header installation, then I'd suggest returning to your installer for some help. I'd suspect a clearance issue beween the header, exhaust and frame or one or more fasteners needs to be retorqued. Finding the specific source of the offending part is best done with the car on a lift and someone in the car to raise the rpm. A pair of heavy leather gloves can help too.

Did your installer use new bolts or reuse the ones from your previous headers?

Ranger
__________________

Ranger, not sure. I will ask. But I figured I'd work backwards with the last modification as a starting point.

Thanks for the advice!
Oz

Just skimmed through some of the replies, but I'll offer my experience...

The LS7 clutch is brand new, but I think I'd let other people test it out before jumping on the bandwagon. I'm very happy with my LS6 clutch on my C5. Very smooth, and it grips great for a stock clutch. It feels much better (after a night at the strip) than my OE LT1 clutch, and it feels better than any of the LS1 Fbody's I've driven. With your mods and plans, get the LS6 clutch.

I had a Street Twin clutch. It cost a small fortune, but it gripped like no other. The flip side of it was that it only lasted about 35k miles of daily duty, and it cost me another 350 bucks to have rebuilt.

I've been to the strip and honestly only seen one C6 Z06 there. The guy could drive worth a flip, and was complaining that his clutch wasn't "biting." While the guy probably had never been to a drag strip before (running 15s in a 500hp car), he was probably riding/slipping the clutch too much on top of everything else. That's only one instance that I've seen, so maybe it is isolated. Everyone like to point out how great the LS7 clutch must be, but I'm just saying to be careful :).

Good luck. Its a bear to change, so I'd rather do it once.

Ryan

Does anyone have the part number for JUST the LS6 clutch/pressure plate? #12570806 is the whole thing including the flywheel, and I don't need that.

Also Ranger specifically which kool sox did you get? There seems to be a lot of options as far as size/length.

Does anyone have the part number for JUST the LS6 clutch/pressure plate? #12570806 is the whole thing including the flywheel, and I don't need that.

Also Ranger specifically which kool sox did you get? There seems to be a lot of options as far as size/length.

Regarding clutch components, your call obviously, but I'd suggest replacing everything while you have it apart (including all the hydraulics). Might want to take a look at my advice in Post #17. Vibration is what you want to avoid in the finished job. Reusing a non-matching flywheel risks vibration.

On the KoolSox, suggest the .75" x 8". One set of 8 should give you enough to insulate separately both the line for the MC and a remote bleeder line to the area near the MC reservoir. You might save some money on the KoolSox by precisely measuring the length of the lines and buying exactly the number of pairs of the larger diameter Sox.

Ranger

Regarding clutch components, your call obviously, but I'd suggest replacing everything while you have it apart (including all the hydraulics). Might want to take a look at my advice in Post #17. Vibration is what you want to avoid in the finished job. Reusing a non-matching flywheel risks vibration.


I already have the #'s for the hydraulics, replacing them is a given because they are the root of my problem.

I was going to get an aluminum flywheel, Ls6 clutch/pressure plate and take it somewhere to get balanced. I can do that, right?

I already have the #'s for the hydraulics, replacing them is a given because they are the root of my problem.

I was going to get an aluminum flywheel, Ls6 clutch/pressure plate and take it somewhere to get balanced. I can do that, right?

keliente, Sure, that will work. But that AL flywheel will make the car harder to launch well and I doubt it will actually improve either the 60' or the ET. And it is less consistent in a near stock car. Notwithstanding, some folks like it.

Ranger

keliente, Sure, that will work. But that AL flywheel will make the car harder to launch well and I doubt it will actually improve either the 60' or the ET. And it is less consistent in a near stock car. Notwithstanding, some folks like it.

Ranger

Groovy. I was planning on having it all balanced no matter what setup I went with.

I don't drag race much at all, so I'm not so concerned with the 60' or ET. What I really love this car for is just cruising & auto cross.

FWIW, a C4 LT1 car was making about 430rwhp with a standard aftermarket clutch. They switched to a Street Twin (which weigh around 50lbs) and lost about 10-12rwhp. Do you know that weight difference in between the stock/AL flywheel? The whole point of the AL flywheel is to reduce parasitic losses, but I'd look other places to help the car.

For a cruiser needing reliability, I'd just stick with the resurfaced stocker. Save yourself the 100-200 bucks for an AL flywheel. However, if its burning a hole in your pocket...;)

Ryan

I'm partial to the Textralia clutch. Stock pedal height. Stock type feel. Good power holding capacity. We're running one in Tommy's car and its making ~503 RWHP.

Ive had great luck with the Spec 3+ so far.....It has great pedal feel, not too harsh and grips like a mofo...Drives almost like the stock Ls6 clutch..It has held 450rwhp(soon to spray to 600rwhp) with absolutely no problems, and I am running the fidanza alum flywheel and mccloud master. That being said I dont daily drive my car, and I do not expect more than 20,000 miles out of this clutch.... In your case Id definitely stick with the stock Ls6 setup, it will have no problems holding 320-350rwhp....

I ran a Ram sintered iron setup before with the fidanza alum flywheel and that thing chaterred like a red headed stepchild in city driving....It held GREAT at the track but was almost unbearable driving around town. The 3+ does not chatter and holds the same or more power.

I have been running the Ram clutch in mine for 4 years and the last 2 with 489 rwhp. It has never slipped once but it is Very stiff! It is the Ram 980.

I like my RAM. One of my really good friends and I are both running them. No problems.

STAY AWAY from Spec, like Jaime said.

As far as the LS7, I would pass.

The "LS6" clutch as it's called is the stock clutch used on all 01-02 F-bodies and all 01+ C5's. I know a few that have toasted them and also most have had sticky pedal issues. My 01 Z06 had the sticky pedal too. It's due to the crappy design of the pressure plate. Almost identical to the standard "LS1" clutch. One of my other friends is getting ready to rip his out within a month and going with somethign better..

For a daily driver with limited track usage... it's ok. Plus it's cheap as hell. But I'd step up..

BTW.. the slave cylinder comes complete with the throwout bearing. Make sure you upgrade both the master and slave..

Steve

Ive had great luck with the Spec 3+ so far.
Me too, no chatter like the SPEC Stage 3, good for 850rwt and installed by my tuner that has done over 40 installs. This is the only thing I have not done myself to this car, I left it to an expert installer, no chances taken. The engagement of this clutch is silky smooth. I have the SPEC flywheel too that is balanced. No noise at all sitting at a stop like the stock ZO6 clutch. The hotter this clutch gets, the better.

The "LS6" clutch as it's called is the stock clutch used on all 01-02 F-bodies

I heard this is not true. The clutch is different/better from the 98-00 f-bodies, but it is not an LS6 clutch. It even has a different part number.

Guys, I ended up going with the LS6 clutch. Money is kind of tight so I had to skip the aluminum flywheel, I'm just going to use the new LS6 one that comes with that setup.

So this weekend, going in I have the LS6 setup, new master, new slave, brass pilot bushing, Koolsox to insulate the lines with, an LAPD remote bleeder, and I'm also going to change the trans fluid & rear end with Royal Purple since I don't even know if they have ever been changed. I will be so glad to have my baby back...I have been driving my grand prix this week since it was no fun to drive with a sticking clutch :(

I heard this is not true. The clutch is different/better from the 98-00 f-bodies, but it is not an LS6 clutch. It even has a different part number.

Guys, I ended up going with the LS6 clutch. Money is kind of tight so I had to skip the aluminum flywheel, I'm just going to use the new LS6 one that comes with that setup.

So this weekend, going in I have the LS6 setup, new master, new slave, brass pilot bushing, Koolsox to insulate the lines with, an LAPD remote bleeder, and I'm also going to change the trans fluid & rear end with Royal Purple since I don't even know if they have ever been changed. I will be so glad to have my baby back...I have been driving my grand prix this week since it was no fun to drive with a sticking clutch :(

You will be fine with that setup... I am using the same and have been beating the crap out of it for over a year (83 dyno runs, 100s of late night WOT runs) with no problems... BTW, I change my clutch fluid every other oil change.

:cheers:

Now that I have the remote bleeder it should make quick work of changing the clutch fluid! :)

Good choices Kaliente.

In case you've missed my customary advice on clutch installations on other theads, here it is:

Four small suggestions to those facing a clutch replacement.

(1) Seach the archives (C5 Z06 and C5 Tech) for the words "clutch" AND "vibration" because there is a history of post-clutch-swap woes you need to be aware of.

(2) Choose your installer carefully. If you don't, the odds are good that you will not be happy with the results. You want a technician with a lot of (favorable) experience in swapping C5/C6 clutches.

(3) Insist that the new clutch assembly be sent to a reputable machine shop for balancing before the installation. Do this even if the installer insists it is unnecessary, "because it comes balanced by the manufacturer."

(4) Before you drop your car off for the installation, be very careful to memorize how much your shifter vibrates under various conditions.

Anyone that shrugs off this advice heightens the odds he/she will end up with notable drive train vibrations, originating from the clutch assembly, and they will have a hard time getting them resolved by their installer or anyone else.

Of the five LS6 clutches I've had prepared for installation in my C5s, four were badly out-of-balance, e.g. off by 40 grams or more on at least one component. Had they been installed without proper balancing, they'd have vibrated the fillings right out of my teeth.

Ranger

and change the pilot bearing too...

Yeah I have one..

Clutch is in, feels great. Also did the left axle seal since it was leaking (not dripping on the ground, but seeping). The transmission shifts loads better now that it has fresh royal purple fluid in it. The clutch is SO much easier to push in, I love it.

I wear sandals/heels to work every day, so 99% of the time I drive barefoot, put my shoes in the passenger seat. For the longest time I have had a towel wadded up & attached to my clutch pedal, because pushing it in bare would make my foot hurt so damn bad since it was so stiff. Now with the LS6 setup, it's much more comfortable ;)

so far so good!

wanna see a naughty clutch....

http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0002.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0003.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0004.jpg

i'll post more as I upload them. I forgot I had these. Now the whole world can remember. These are some pictures of my spec clutch failure in my last corvette. It did total the car. i'll show some in car shots.

More...never before seen pictures from my car.

http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0132.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0133.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0137-1.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0136-1.jpg

more...

http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0135-1.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0134-1.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0141.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0140-1.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0139-1.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0138-1.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0144.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0143.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0142.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0150.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0147.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0146.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0145.jpg

..and ofcourse lastly, the proof that I did indeed at one point, due to these clutch woes...have two white, 2000 FRC's... here they are. My old car, is seen in these pictures with the DARK wheels. The one I have now, no longer has the silver wheels but, my old gunmetal painted factory stock wheels. (no I have black Z06 wheels)

http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0028.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0027.jpg
http://i70.photobucket.com/albums/i86/V-seriesTech/Imag0026.jpg


Thats it.