kramsdell

A few months ago I installed the tick MC in my car and I've been loving it. Smooth shifts through and through. I took it to the track last Sunday and my first run I went through the wetbox and did a short burnout to dry/heat the tires, after I rolled out I noticed my clutch pedal was extremely hard to depress. After several pumps of the clutch pedal it almost went back to normal. When I took off from the line I could not get the car to accept second gear at all until a few pumps of the pedal. I limped down the track and tried another run, this time completely avoiding the wetbox and doing no burnout whatsoever. The shifts were smooth and I ran my best time yet. My question is, what would cause my clutch pedal to be hard like that only after burnouts, and be fine shifting at 5.5-6k down the track? Confused as hell right now...

SNLPerformance

iTrader: (15)

I assume this is a stock clutch, how much power are you making?

Nmbr1GMfan

iTrader: (1)

The way you are doing burnouts may be introducing too much heat into the clutch/fluid. I have seen people at the track slipping the clutch too much then having disengagement/shifting issues.

kramsdell

01 T/A, I only have SLP lid and a catback. Stock clutch, as far as I know, it grabs good when I can actually get it to engage. Do I need to adjust the master cylinder out further? I don't want to overextend my pressure plate. I just don't understand how a short burnout will make my pedal stiff, but on runs where I do no burnouts, and even shift at 5.5 or 6k the pedal feels good.

SPEC-01

iTrader: (2)

The short answer: Heat!
The long answer:
The fact that you are seeing the pedal get stiff would lead me to suggest the use of a Line-lock! I know, some may argue that it isn't required but everytime you do a burn-out without it (and are using your brakes to maintain the cars position) you are causing your clutch to fight your brakes and this can cause slip and subsequently great amounts if heat. Additionally, if the line that connects the Master to the Slave is not routed properly this too can allow the hydraulic fluid inside to boil as a result of the lines proximity to the header.

The first suggestion is to check the fluid in the reservoir. Is it dark or cloudy? If so, flush and refill. Additionally you want to check the routing of the aforementioned line. And if you don;t have line-lock...get it! Let me know if you have any further questions. Thanks!!

kramsdell

I'm not using my brakes to do a burnout at the moment, just running street tires and trying to avoid the wetbox, then doing a couple second spin out to the line to dry them/clear them of debris. I wrapped the tick unit line in heat tape, and wrapped the heat shield in heat tape as well.

I'm running stock intake manifolds, and they look like they have a heat shield around them, but the line does get very close to it. My fluid was pretty dirty the day of the track runs, but I ranger bled it and cleaned the reservoir and refilled with the same Prestone DOT4 fluid. (several times, to get the fluid looking good)

I think I've done just about everything I can do avoid heat. Hell, I even cut holes in my damn floorboard in order to run the line inside the car, and back out, into the transmission. If I ever get serious and go to the track more than twice a year I'll look into a line-lock, but until then I just want my damn clutch pedal to not fight with me after spending a lot of money on a tick unit.

SNLPerformance

iTrader: (15)

Doing a burnout in 1st gear will put less heat into the clutch if you're only on street tires and just needing to clean them off.

kramsdell

First gear is what I used, which caused the stiff pedal. After that, no burnout whatsoever and everything was OK.

SPEC-01

iTrader: (2)

The effort required to compress the diaphragm fingers should not change as a result of heat. This why it seems most likely to be relative to a fluid-transfer issue. It sounds like you do have a lot of steps taken to keep the temps down in an effort to be preventative--good job there!

Cass007

Having a similar issue, but on the dyno and street. Just finished an LS2/T56 GTO dropout swap into my '05 350Z and when I shift hard from 1st to 2nd I am getting the stiff pedal. I am also seeing some slippage over 5K rpms. Time for a new clutch? The dropout had 26K on it, but I have zero knowledge of the driving habits of the owner of the GTO.

SNLPerformance

iTrader: (15)

Sure sounds like unless you have some fluid contamination contributing to the slippage. Heat changes the properties of a spring...that's why there are different qualities of material. Also people generally break valvesprings on engines that haven't fully warmed up...

jason89i

any updates on a fix. i have a hard time believing its heat transferring to the fluid.

I have an '06 gto / t56 stuffed in my 88 m3. Shifts normal all day long. if it revs past 6400 the clutch pedal is instantly 5x as stiff. Pump clutch once, its back to normal. Full throttle up to 6k rpms, no problems. go over 6k rpm and it immediately has a stiff pedal. any gear, any speed.

06 ls2
t56 with factory clutch. (34k miles.)

wilwood compact master / pedal assembly.
stainless lines to new factory throwout / remote bleeder.

any insight would be greatly appreciated.

Jason

LS2-240z

I just worked thru this. Tick uses a Tilton master cylinder. I am finding that these master cylinders are very hit-or-miss. It isn't Tick's fault. Make sure that your pedal is adjusted (if it is adjustable) to allow the master cylinder to return totally up with a little slack in the pedal at the top. If that doesn't fix it, replace the master cylinder. You MIGHT get lucky and get one that works properly. I've had 4 of them and 2 of them worked properly. In Tilton's defence, MAYBE I screwed the seals up with my Mighty Vac. But, after weeks of trying everything else that has been recommended to you, including replacing my slave, insulating lines, new clutch, pressure plate and flywheel, and bleeding 5 quarts of fluid thru the system; it was replacing the master that did the job.

BALLSS

OP

sounds like "heat" is causing your issue be it hydraulic or clutch induced from burnout since your clutch seems to operate fine if not doing burnouts.

FWIW I have a Line Lock for burnouts and after going through water box I take it to 2500 RPM and DUMP the clutch in 2nd gear keeping RPM's in the 3k is range during burn out. I run MT ET Streets so do want to warm them up. For just street tires just a short spin in 1st gear should be fine as you really don't benefit from heat in a street tire.

My point is don't let clutch out easy on burn outs. Commit and dump it.

Your particular hydraulic set up may be prone to heat for multiple reasons so sort through that. If your clutch slips excessively during burnouts it will heat up very fast and could cause disengagement issues which may feel like "hard pedal". Confirm you have enough travel on slave piston/bearing to operate clutch properly