Hi,

After launching at 6.8 krpm in 1st gear and burning rubber, the clutch didn't fully engage when I shifted from 1st to 2nd. I could feel the clutch pedal stuck close to the floor and almost no power going to the wheels. This caused the clutch to slip (I'm sure of this from the smell).

After letting it cool off, the car drives normally except for the smell.

I find that this is a strange problem, and I know it didn't happen because of the high rpm I launch the car, because the same thing happen before when I launched it at 4krpm.

There must be something sticking in the hydraulic when shifting at high rpm from 1st to 2nd.

This is frustrating because it is not the driver that is ridding (slipping) the clutch but it is the hydro-mechanical clutch engagement system that is not doing it job properly and causing the clutch to slip.

Did anyone had a similar problem ?


2005 G35 6MT 37.5k miles
window : 65% rear, 35% front

 

Well in most hydro clutch set-ups you have a master and slave cylinder. I'm gonna guess our cars are the same and I'de have to guess either contaminates in the fluid or a sticky slave cylinder. A slave cylinder is the cylinder that pushes the fork arm and releases the clutch. Just a guess tho

 

Did you check your fluid levels? I forget the actual cause, but I think this is a somewhat common issue. Search for it, you'll find answers. Also, while launching at 6800rpm will not cause your pedal to stick, it certainly isn't good for the clutch. When you need a new one at 45k, its probably because of your driving style, not the car. (ps, not trying to be a dick)

 

[QUOTE=KevinHeld]Did you check your fluid levels?

If you fluid is so slow that it causes your clutch to not fully engage then you have a bigger problem than low fluid. Probably a bad seal on the slave or master cylinder.

 

I think our cars have a weak clutch. Anytime i do a hard launch with my 20's my clutch slips... Looks like its time to upgrade you clutch.

 

def need to upgrade to a better grabbing clutch. this happened to me a few times on my first clutch. i feel that when your rolling like 2 mph it catches no problem

 

Whoever is complaining about the car having a weak clutch is out of his mind (for 03-04s). U guys need to learn how to drive the damn car before u complain. I have launched the car from 2500rpm all the way up to 4500rpm and never had any smelling or slipping issues. It takes a lot of not proper driving to make this clutch smell. Even constant 2k rpm casual launching would not make the clutch smell.
To the original question: Why the *** would u launch a rwd car with 230 tq at 4500 rpm from 7k rpm? even to do a decent burnout all u need is to dump the clutch at 4000 rpm, but slipping the clutch at 7k rpm?? And after that u complain that the clutch is weak? LOL U need driving lessons.

 

I'd say someone isn't learning from their mistakes.

I love these threads. They never fail to entertain...

'My clutch smells like charred a$$, what do I do?'

 

Fellow g35 drivers,

Thank-you for your thoughtfull comments.

The original problem was during a launch at 6800 rpm, the clutch pedal would not return to its release position when shifting from 1st to 2nd gear.

The problem is not due to insufficient clutch fluid.

When driving around 60km/h I carried a test, which consist of putting the car into sixth gear
and pressing the gas pedal to the floor, no slippage of the clutch, the car speed increased
proportionally with the rpm.

I carried an other test, which consist of launching the car at 4500rpm, when I shifted
to 2nd speed the clutch pedal reacted normally.

------------

The cause of my problem,

is that the g35 like any other sport cars,

can't be launch a such a high rpm.

At 6800 rpm the engine develops close to 300shp. With a stand still car, dropping suddenly the clutch cause yes ! the wheels to spin, but also the clutch to slip since the spinning of the whells cannot absorb all this energy.

The energy is absorb in the pressure plate, which is a "metal spring", heating it up to a point were when I come to shift from first to 2nd the pedal would not return. This is because the pressure plate stiffness is acting against the clutch pedal through the hydraulics.

My clutch is still good.

I won't launch my car like this anymore, but I
needed to find the limit of the car.

The g35 is a taught car but it has its limits.

Thanks to all.

 

There is no need to launch your car at that high of an rpm. Not only will it cause premature wear of the friction material it is hard on the tranny, rear diff and axles. First gear is so short in our cars a ~3-4k launch is more than enough.


As for the clutch being weak, that is not true at all. Depending on what wheels you have, you could have doubled the unspring mass in the back as well as the added traction from the wider tires; both which will dramatically change how you car reacts at takeoff. I can tell you that I ran heavy 20's (Zenetti 20x10's) in the rear with my Stillen Stage 4 SC on the stock clutch for a while with no problems. The only reason I upgraded when I did is because I had the common synchro problem and got a new tranny under warranty so they installed my JWT clutch and UR flywheel at the same time.