My "end goal" for this car was a HCI setup that is VERY street friendly and derivable. I knew once the heads were done I'd need a clutch...however the car had other ideas. When casually driving to a friends house I pulled into their driveway, downshifted into 1st to "chug along" and when I went to stop, I put the clutch in and it went limp . No fluid under the car, just the very last 1" of pedal travel would you feel the clutch build resistance to push the PP fingers...odd. So it sat for 3 weeks figuring out clutch options/schedules at the shop and ordering parts.

The car:
03 C5Z
Full exhaust
BTR STage 2 cam
Dorman LS2 intake (Ported Dorman LS2 Intake+Results)
LS3/7 CAI
Ridetech coilovers
C6 ZR1 swyabars

How I use the car:
I USE this car. I love to drive it and simply be in it. It's a 80% daily driver as much as I can except for when there snow/ice on the roads. It also is used for local autocross in CAM-S that I do maybe a couple times a year (but working on doing more). It will eventually see a road course or two. All racing is for fun and something to enjoy with my wife who ALSO has co-driven my old 95 Camaro Z28. She will drive this car and race this car with me eventually. We also plan to take trips in this and go anywhere we want to.

The goals for clutch choice:
Given the above, I wanted something that was an upgrade from stock...I mean what car guy doesn't? There are SO many options I ended up making an EXCEL sheet comparing Mantic/RAM/McLeod/SPEC/Monster/QuarterMaster/LS7/stock LS6 units for weights, overall diameters, clutch materials, clutch design (puck or full face) and cost . I went further to find all specs on aluminum FW offerings. I knew products like RPS was WAY out of the budget and intended use for this car.

The clutch/FW combo needed to be lighter than stock LS6 unit, I knew I wanted AT LEAST an aluminum FW option (no brainier to save weight), retain VERY good street manners since I like to drive and my wife will drive it so pedal pressure could not be a dramatic increase from stock. Oh and I wasn't wanting to spend $1200+ on JUST a clutch/FW when I knew I needed to get a slave cylinder/pilot bearing/clutch MC (more on this later) torque tube bearings and couplers (if needed for rebuild).

Taking action:
With the car "dead" there were three possible issues. 1) The clutch MC failed and was not pushing fluid. 2) The slave failed internally (since it was not leaking) 3) The PP fingers failed. So I started with the cheapest option and replaced the MC with a Tick/Tilton 3/4" Bore unit. I did this for a couple of reasons. 1) I went with the Tick/Tilton IN CASE the clutch that I MIGHT NEED required an adjustable unit (some clutch companies suggest a 7/8" bore in which case I COULD swap to a 7/8" if needed). 2) I went 3/4" bore because I did not want a lot more pedal effort...see reason #1. Replaced the MC...and no dice...something inside the bellhousing failed. SO went forward with finalizing clutch and ordering parts.

With help of my friend that owns a local speed shop and calling Spec tech support I went with a Spec Stage2+ 10.5" with aluminum pressure plate mated to their 10.5" aluminum FW. I discussed with Spec my uses/goals to confirm the 3/4" bore MC and that the 2+ is better suited for my future HP goals of ~450/400 at the tire. Their ratings are at the FW. This new combo came in at 31 lbs which is almost 20lbs less weight AND smaller overall diameter.

Other parts:
LUK Slave Cylinder
AC Delco pilot bearing
Tick Slave shim kit (ended up using thinnest shim)
Tick Slave Quick disconnect tool (WORKS GREAT for as simple as it is)
12mm torque tube couplers - FEBI/Bilstein 5084
AC Delco slinger 12456208
Torque Tube bearings SKF 6008-2RSJEM (qty 2) and SKF 6007-2RSJEM (qty1)

We all know the PITA and how big of a job this is so no need to hash over the struggles/details. I did it on a lift with a trans jack and all the proper tools needed...after all this was done at a speed shop lol.

Key notes:
-The snap ring on the TT is no joke. People said it was hard and I can confirm. Even using "larger than normal" snap ring pliers it was a struggle and you WILL pinch fingers or the ring will fly around unless you use the "official" pliers for the job that are the size of hedge trimmers LOL.
-My TT couplers and bearings looked and felt AMAZING so in the essence of time and all things considered...we made a call to NOT replace them and to reassemble the TT.
-Clutch itself installed easily and as expected
-BE MINDFUL OF THE SHIFTER LINKAGE WHEN PUTTING IT BACK ONTO THE TRANS AND WHEN RAISING EVERYTHING INTO THE CAR. When I mated the TT to the trans I missed the fact the shifter linkage was up against the aluminum block welded to the TT to hold the shifter base...I proceeded to pull the TT onto the trans with all the bolts and THEN realized what happened. This, as it turns out) must have slightly bent the linkage because reinstalling the shifter and trying to shift gears made things slightly "off". My buddy had the idea to elongate the mounting holes in my MGW shifter base to accommodate this misalignment and all is well. When we went to raise the whole assembly for install, the damn linkage got sandwiched between the TT and the lip of the tunnel where the belly pan bolts to which started to raise the body . Rookie mistake on my part as I was the one to install the TT on the trans AND I was "up front" guiding everything into the car as the shop owner operated the rear cradle.
-DO NOT USE THE LOWER BELLHOUSING BOLT TO PULL THE TT ASSY TOGETHER. Mine was already cracked in 2 places and shop owner cut grooves, sprayed it with brake cleaner then use a propane torch to urn out any impurities then did a weld repair. We needed longer bolts placed at the 3/9 o clock spots to gradually pull the assembly together to overcome the slave against PP fingers.
-Plan to cuss and freak out when you see half your car coming out from under it LOL

First 50mi driving impressions:
Even at 20lbs lighter assembly, it's not THAT drastic of quick revs nor does it need a lot more RPM to get the car to move from a stop. This MC and clutch combo is VERY nice, the pedal effort is slightly more than stock but this is still 100% streetable. The pedal travel has been reduced which is nice as my pedal sits maybe 1/2" below the brake pedal. Engagement is smooth and easily modulated. No chatter or excessive idle clutch out noise, it is slightly nosier than stock but IMO nothing to be annoyed with. Doing back to back 3/4 WOT pulls on the highway to 6000rpm results in maintained pedal firmness where the stock setup would "go limp". I'm very happy with this clutch/MC combo so far. Looking forward to finishing the break-in miles and putting it through it's paces at a local event at the end of the month.

Once I get more miles on it, I will hit the dyno to see what gains are to be had with this clutch setup.

Overview pictures:

It's out

Cracked bellhousing and repair

Look at how porous this casting is

Welded/sanded and tapped

PP failed as you can see an air gap on some of the fingers:

It's in and installed according to the SPEC yellow orientation marks. No need to "match balance" to stock setup.

I'll try to remember any updated on this as time goes on as I break it in. Any questions, let me know and I'll be happy to help.

Big shout out goes to @CinciZ06 for letting me ask a bunch of questions and confirming things for me as he just went though this as well. Thanks A LOT! Conversing with him put me more at ease with what I was getting into and had no hiccups along the way (other than the stupid self inflected ones).

 

Nice work brother! Looking forward to hearing how it treats you over time. I have a feeling I’ll have clutch envy! Haha

 

Thanks! With only a 5 mile commute one way to work gives me a 10mi round trip, this "500mi break in" will take me a month and a half to do! Gotta find places to drive! Local event is July 25/26 so I got some work to do.

I did not see many people running this setup and figured I'd take a chance on it. Price was right for the performance offerings.

 

Even though my clutch only has 33k miles on it I will be heading down this road shortly. Thanks for the review/write up Smitty! especially now that the belt driven intake manifold appears to be a go.

 

No problem. Goodluck with the selection! There is plenty to choose from lol

 

Nice work and write up! Spec makes good product. Hope it lasts a long time!

 

Thanks. This is the first SPEC clutch I have used. So far so good and we will definitely see how this holds up.

I may still play with the Tick MC for pedal heights, but where I have it now you barely need to lift your thigh'leg off the seat to use the clutch. You can almost roll your foot over from dead pedal to clutch pedal and use only flex your ankle to depress the clutch.

 

My 02 C5Z had the standard size 12" 2+ with billet aluminum PP and aluminum flywheel. With the multi-friction disc in the 2+ it drove smooth as any factory unit. I added a Mcleod adjustable MC later to fine tune the engagement and it was a great combination of drivability, performance and cost. In combination with a mild cam 226-230 I could idle through parking lots without a hint of surge or bucking and driving HPDE events I could wind it to 7K and shift without fuss so the clutch had all the boxes checked. I believe that assembly weighed around 36-37 lbs but if the 10.5" was offered at the time I would have gone with it. Good Choice.

 

220mi update:

My wife and I took a trip around NKY to some nice backroads and logged a total of 101.6mi . The clutch saw extended 2nd/3rd 5000rpm between turns, upshifts/downshifts and plenty of rev matching. Got on some open roads and let it eat to 6000rpm with ZERO issues with the "limp clutch pedal" after.

It grabs harder now and needs a little more RPM at a stop in order to not have it shudder/chatter. I chalk it up to the puck style disc being a slightly more aggressive design than a solid disc. With the cam I have I noticed a little more tendency to buck but nothing major and easily managed. Pedal effort with the Tick 3/4" bore is still REALLY nice. Real happy with this combo.

First autocross event is at the end of the month for a Sat/Sun. Since last year the car got coilovers, ZR1 sway bars, 315/335 Rivals and now this clutch. Swing for the fence!

 

Hi All:

I just came across this thread because I am looking to upgrade my master cylinder and have heard good things about the TICK unit and would like to solicit input from the forum.

Also, I happened to install the same SPEC 2+ clutch and lightweight flywheel a couple of years ago at 129k miles. The car now has 133k miles. I'm putting down about 405 hp to the wheels. It has worked very well but as noted does require a little higher revs to get off from a start. When new the clutch would squeal/chatter a little from a dead start in 1st but that has for the most part gone away as the unit broke in. I found that letting the clutch engage a bit more quickly would minimize it. I have autocrossed it 3-4 times now and the new clutch set-up is great. Really bites nicely!

I am having an issue though lately which is why I am considering the new TICK MC. I've noticed that when shifting from 1-2 & 2-3 after full throttle acceleration the transmission doesn't want to allow the shift until the revs have come back down. Standard shifts when driving mellow on the street are smooth as silk. Also, shifting into reverse takes some effort but it never pops out as I have heard some people have trouble with.

I should note that the transmission was completely rebuilt by the ZF DOCTOR (Bill) in Phoenix at 111k miles and as he said, "I'll build you a bullet proof tranny that will be much better than a "rebuilt" one", and he did (I've got details of the parts used if anyone is interested). I've changed the transmission fluid (REDLINE DT-ATF) and differential fluid (REDLINE GL5 75W-90) every couple of years or 10k miles. Also, when he did the work he installed a new clutch slave cylinder and remote bleeder so I also bleed the clutch system every year.

So anyhow, I was told that the stock master cylinder is a weak link in the C5 and that it doesn't have quite enough stroke which causes the issues that I am seeing and that the TICK unit will solve my issues. The TICK website claims this as well. I would appreciate any input insights that you can offer before I order the TICK unit. Also, I have heard mention that there are two versions, one with a 3/4" piston and another with a 7/8". Can anyone tell me what the trade offs are and which you would recommend to address my issues?

Thanks in advance!

Tom

 

The Tilton MC is a better unit. Tick puts a kit together to work in the C5. It's nice to have the pedal be adjustable (within reason) for your driving style. I have my pedal on the lower side so all my pedal movement is by ankle pivot only. I don't have a need to lift my thigh off the seat to get on top f the pedal. Really nice. Be mindful of adjustment though since you can adjust the pedal so far (high) you will over extend the slave.

The stock MC MAY be the issue and or the slave. With only a couple thousand miles on the clutch (I assume you replaced the slave as well?) then the MC may be getting tired. IMO stick with the 3/4" bore unit to keep pedal effort close to stock. I don't know why it is almost a $40-50 up-charge to spec a MC kit with a 3/4" bore...3/4" is what is stock in the C5.

I now have a tad over 550mi on my setup and zero issues. I have another two day autocross event this weekend and expect it to "just work". Saturday will be a Novice event and my wife will be racing the C5. Sunday is a points event for me to give it hell.

 

Hi Smitty: Thanks for the reply! Yes, we put in a new clutch slave cylinder when doing the tranny work. Replacing the clutch master cylinder is about the only thing in the system that has not been renewed and since it's original with over 130k on it and now being 21 years old is worth doing. With the SPEC Stage 2+ clutch I do not want anymore clutch pedal effort (it's already stiff enough) so I will inquire with TICK about the 3/4" vs. 7/8" version. Also, I will be mindful of not setting it up so that I would overtravel the slave cylinder. Thanks for the tips!

Good luck autocrossing! I normally race my 2004 Mazdaspeed Miata for autocross but 2x per year the local Corvette club (Corvettes of MN... http://corvettesofmn.com/) puts on an event and then I take out the Vette and race in CAMS. Very different cars but both are fantastic. I've taken the Vette to BIR (Brainerd) a few times over the years and it's really better suited to a higher speed track where you can use all the power than autocross but we race at DCTC which is a mini road course of sorts and so they typically set it up to allow fairly high speeds in certain sections which is fun. Glad to hear that your wife is into it too! Good luck!

 

Very good write-up. Best of luck with your new clutch.

Moving this over to the Tech section for further comment.

 

Thank you. Hopefully shed some light on another street-able clutch that is a weight benefit but not terribly expensive.

 

Well in the name of science....I decided to dyno the new clutch combo.

Before/after losing 20lbs off clutch/FW assembly. Decent area under the curve in the midrange RPM.

 

You'll see a bigger difference in the first few gears. The faster RPM is changing, the more it helps. I have a Spec Stage 1 alum fw/pp and the difference in acceleration was very noticeable. It does vibrate though, does yours? Mine vibrates close to 5000 even with the paint marker lined up.

 

No vibration pulling to 7000-7100 rpm.

 

I'm hoping this one was custom balanced to the PO's factory imbalance. We'll see here in the next few months.

 

Found my way in here from the RR/AX section, I'll add some closure to my scenario. Whoever balanced the clutch initially put the right amount of balance weight 180 degrees out. I love this clutch though, if it dies I'll get another.