I posted a while back that I was having intermittent issues with clutch fluid overheating while at the track. So, I changed the clutch fluid to ATE Super Blue and wrapped the external clutch lines with heat shield material.

After that I did a track day in June with fairly hot ambient temps and had no trouble at all.

This weekend I ran at Carolina Motorsports Park. Got over two hours of track time on Friday, it was about 80 degrees out, only 30 minutes between sessions. No problems. Ran 4 sessions on Saturday, cooler weather, no problems. Ran two sessions on Sunday, cool weather, no problems. Then went out for session three and lost the clutch pedal again after only two laps. As usual, let the car cool down for no more than a minute or two and it comes back.

I am completely stumped now. Decent clutch fluid, CSC has no more than 10k miles on it, clutch lines wrapped. AND this happens after only two laps. Car was completely cool before this session.

It has to be a heat problem because it goes away. No problems while driving home. But why after only two laps?

Has anyone here had to wrap the cat that runs next to the clutch lines?

My clutch is original oem with 75k mile on it. Is there any chance that it could be slipping enough to overheat the CSC.....without me noticing it slipping or smelling it?

Any help much appreciated since I can't plunk down any more track day entry fees until I get this sorted.

George

 

Keep the fluid fresh is the best advice.

Removing the cat and running a wrapped test pipe will lower the temp around the fluid

 

I think you've still got some air in the system. Try bleeding the clutch while it's still hot and see if you get any bubbles out. This is particularly true if you aren't losing any brake fluid between sessions. Finally, on the track, are you using heel-toe technique and rev-matching on downshifts?

 

are you using the oem line or all the after market ones?

 

I do heel and toe. No clutch fluid loss. OEM clutch lines. Are there better ones?

I do not know how to bleed the clutch line. I had the dealer do the flush and fill last time. It was only about 5 months ago. I wonder if they left some of the old fluid in the line.

The thing is, no problems for two days then all of a sudden it crops up again after two laps in a cool car. That is why I was wondering if there was some abnormal excess heat coming from somewhere like the clutch slipping. But again, I never smelled burning clutch, never sensed that it was revving higher than expected, no loss of power that I could feel........although my lap times were falling......

Not sure how to check a for a slipping clutch.

 

factory cats or test pipes, cant remember if you have OEM csc or after market. to see if clutch is slipping, get going about 20 mph in 4th gear and hit the gas, if the rpms jump up without you gaining much speed then it is slipping

 

I went to the Z1 steel braided clutch line covered in DEI Fire Sleeve and never had another problem.

 

i am thinking he has an HR because he keeps saying csc....if that is the case they are a little different

i did the wilwood master and zspeed heavy duty csc, they have all new braided lines that should be ran next to the factory lines they come out and it is like under 5 inches til it goes in transmission... it is not up front by the cat like the de's

 

Makes sense. With a truck I'd just bump the front tires against a curb, put it in 4th and let the clutch out. If it didn't stall, clutch was bad.

I haven't had a chance to test it, but on the track Saturday a car got loose in front of me and slowed down a lot and instead of downshifting into third I left it in fourth and punched it and it revved high and didn't take off. So it has to be the clutch.

And yes, it is a 2007, HR.

And since it looks like I'm going to need a new clutch I need to look into that heavy duty CSC and braided lines too.

What is the benefit of the Wilwood master? Does it bolt right up or do you have to fab a mount for it?

 

it is a little bigger and better quality, and yes it bolts right up. if you are going to replace it or the clutch, do it all at once since you will have it out already. with the zspeed hd one bleeding is easier

 

Thanks.

Might as well ask the next obvious question: Which clutch should I get?

Car is current DD and DE-4 track car. No engine mods now or planned. Will likely remain in DE-4 but could dabble in NASA TTC. Virtually any performance mods would put me in TTB where I would be even less competitive. So less is better. I'll have to review the points penalty for clutch upgrade but I think any upgrade plus R1 tires would put me in TTB.

If I don't do time trials (and I probably won't) I'd want the most aggressive clutch that was still manageable on the street.

From a practical, and financial, standpoint OEM will probably be best I guess.

 

oem will be more than any after market. clutch and flywheel combos are about 800 for after market depending on what you get. i know the JWT is a good one, and i know several (i will get one when time) that have done the southbend daily or stage 2....

 

Got my street tires and brakes back on today and took the car out to test the clutch. It does not slip. In fourth gear, 20mph and punch it and it either bogs down or goes. No revving. Park it, put handbrake on, fourth gear, give it gas, ease clutch out and it either stalls or moves against the handbrake.

So I'm back to the mystery. Why do I get a clutch pedal staying on the floor after only two laps at the end of a 3 day track weekend and as soon as car cools down everything works fine. It just does not make sense.

I guess I'll have it bled again. I think I'll put Motul 600 in there this time. I'll have to do a single track day on a weekday (fewer cars, more time to test and fix, etc) before plunking down big money for a full weekend.

As far as the cat, I've heard different things about wrapping one, good and bad. If I replace the cat on that side with a test pipe I'm assuming I'll need to replace the other side as well? Will the engine need a tune after that? I also wonder about the sound. I've heard Z's with test pipes and god-knows-what downstream that were the worst sounding cars I've ever heard.

Has anyone tried making a metal heat shield or baffle between the cat and clutch tubing?

 

THIS

Good suggestion. I just helped change one of these on my back this weekend on a buddies 05. No fun.

 

The collective wisdom of the internet (for what that's worth) says not to wrap a catalytic converter. I'm still uncertain about that.

Put Motul 600 in for clutch fluid today.

Got under the car and the DEI heat wrap is still in place around the clutch lines. There are a few small gaps in hard to wrap places but I'll try to get them covered.

Looking around under there it looks like there would be room for a heat shield between the cat and the clutch lines as well as where the clutch lines enter the bell housing.

I think I could fabricate a heat shield if I had the right material. I think I could attach it where there is a clutch line bracket that bolts onto the transmission and I could drill a hole in the bracket that the cats mount to as the second attachment point.

But, I don't know what material to use or where to get it. I've got some stainless steel flashing used for roofing and siding trim on houses but it is pretty thin and might be too flimsy. Anyone know where I can get something that would stand the heat (it would stand off about an inch from the cat), be flexible enough for me to bend as well as cut and bend some tabs for mounting?

 

Correction: The flashing I have is aluminum. That would have been a disaster!

 

I wrapped my Driver side Test pipe in the race car...

I have some stuff you can use...lemme see what I have and I will send it to you...I will post some pics Saturday

You can buy the beer next time I see you at the track.

 

Thanks John.

I do not have test pipes on yet. Still OEM cats. I'm assuming test pipes would produce a lot less heat than a cat anyway. Probably need to go ahead and get a set. The car is my DD but here in SC we do not have inspections or pollution testing so I could get some test pipes. I've heard the stock exhaust sounds terrible without the cats.

 

i think test pipes give off more heat because they don't have the integrated heat shield like the factory cats. when i went from stock cats to kinetix, i noticed some more heat coming up the side of the door, and when i switched to ART pipes i noticed it a little more.... don't think it was my imagination...... can someone else chime in on this?

 

N80 Check out this product on my website...I will send it to you for only shipping cost . Most of this stuff is left over from my Spec Z when I sold it suddenly. I had planned to do a full heat treatment to the undercarriage...but sold the car

http://www.partsatlanta.com/store/p2...at_shield.html