Clutch "chunky" when Hot

ShiftZ · 04-15-2015, 12:47 PM

Hey guys, The other day after a bunch of hot runs at an autocross, my clutch started to feel "chunky". This was after about 6 hot laps, the car was getting pretty warm (but the clutch wasn't really being worked since I was in 2nd the whole time). I sat in the pits and cycled the clutch a few times and let it cool down, and it went away.

I'm not sure the best way to describe it. It wasn't what I would call spongy, but it was just not smooth engagement. Almost felt like the slave cylinder wasn't sliding smoothly over the shaft.

I have recently installed a Southbend Stage 2 clutch, HD CSC and SS clutch line from Joe at ZSpeed. I have about 800miles on the setup. It was bled well according to Joes instructions when it was installed and I havent had any issues during normal street driving that would make me think that there is air in the lines.

Any ideas? Has anyone experienced this before?

DR_ · 04-15-2015, 01:51 PM

High flow cats? They don't have heat shields like the stock ones and the heat can boil the clutch fluid.

Chuck33079 · 04-15-2015, 01:54 PM

Quote:

Originally Posted by DR_

High flow cats? They don't have heat shields like the stock ones and the heat can boil the clutch fluid.

Beat me to it. OP, what fluid is in there?

jwick · 04-15-2015, 02:15 PM

Quote:

Originally Posted by Chuck33079

Beat me to it. OP, what fluid is in there?

Clutch fluid could be part of it. I recommend a synthetic and highly recommend getting some thermo-tec heat sleeve and wrapping your clutch line feeding into the tranny.

ShiftZ · 04-15-2015, 08:17 PM

Nope, stock Cats. It has Motul 5.1... has a boiling point thats 50-60 degrees F less than RBF600 I believe.

ShiftZ · 04-15-2015, 08:19 PM

Forgot to mention too... the SS clutch line from ZSpeed is wrapped in heat shield as well. If its still boiling after all that, what else can even be done?

MR.nismo · 04-16-2015, 01:05 AM

Misleading thread tittle. I though for a moment that he meant to find hot and attractive when they are chunky...the ladies
But then I checked and I was in the correct section.
Cheers!!!!!

ShiftZ · 04-16-2015, 08:27 PM

Any other ideas? Have you guys experienced your clutch fluid boiling this easily?

04-15-2015, 12:47 PM	#1 (permalink)
ShiftZ Base Member Join Date: Jan 2015 Location: Peoria, IL Posts: 30 Drives: 2009 370Z Touring Rep Power: 10	Clutch "chunky" when Hot Hey guys, The other day after a bunch of hot runs at an autocross, my clutch started to feel "chunky". This was after about 6 hot laps, the car was getting pretty warm (but the clutch wasn't really being worked since I was in 2nd the whole time). I sat in the pits and cycled the clutch a few times and let it cool down, and it went away. I'm not sure the best way to describe it. It wasn't what I would call spongy, but it was just not smooth engagement. Almost felt like the slave cylinder wasn't sliding smoothly over the shaft. I have recently installed a Southbend Stage 2 clutch, HD CSC and SS clutch line from Joe at ZSpeed. I have about 800miles on the setup. It was bled well according to Joes instructions when it was installed and I havent had any issues during normal street driving that would make me think that there is air in the lines. Any ideas? Has anyone experienced this before? __________________ 2009 Monterey Blue 370Z, Touring Sport package, Swift Spec-R springs, Koni Yellow struts

04-15-2015, 08:17 PM	#5 (permalink)
ShiftZ Base Member Join Date: Jan 2015 Location: Peoria, IL Posts: 30 Drives: 2009 370Z Touring Rep Power: 10	Nope, stock Cats. It has Motul 5.1... has a boiling point thats 50-60 degrees F less than RBF600 I believe. __________________ 2009 Monterey Blue 370Z, Touring Sport package, Swift Spec-R springs, Koni Yellow struts

04-15-2015, 08:19 PM	#6 (permalink)
ShiftZ Base Member Join Date: Jan 2015 Location: Peoria, IL Posts: 30 Drives: 2009 370Z Touring Rep Power: 10	Forgot to mention too... the SS clutch line from ZSpeed is wrapped in heat shield as well. If its still boiling after all that, what else can even be done? __________________ 2009 Monterey Blue 370Z, Touring Sport package, Swift Spec-R springs, Koni Yellow struts

04-16-2015, 01:05 AM	#7 (permalink)
MR.nismo Enthusiast Member Join Date: Nov 2011 Location: Hackensack, NJ Age: 50 Posts: 373 Drives: 2014 Nismo Gun Metal Rep Power: 14	Misleading thread tittle. I though for a moment that he meant to find hot and attractive when they are chunky...the ladies But then I checked and I was in the correct section. Cheers!!!!! __________________ Sarcasm and Orgasm are about the same thing. One is good....the other is better.

04-16-2015, 08:27 PM	#8 (permalink)
ShiftZ Base Member Join Date: Jan 2015 Location: Peoria, IL Posts: 30 Drives: 2009 370Z Touring Rep Power: 10	Any other ideas? Have you guys experienced your clutch fluid boiling this easily? __________________ 2009 Monterey Blue 370Z, Touring Sport package, Swift Spec-R springs, Koni Yellow struts

04-15-2015, 01:51 PM	#2 (permalink)
DR_ Track Member Join Date: Jul 2009 Location: Dallas Posts: 981 Drives: Touring/Sport M6 PG Rep Power: 17	High flow cats? They don't have heat shields like the stock ones and the heat can boil the clutch fluid.

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