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Discussion Starter #1
ok, so the other day i figured i'd try a fast start, got it to about 4500 revs, let the clutch out really fast, and all i see in the rearview mirror is smoke, and not from the tires, now whenever i try a mild acceleration, and even to break the tires loose in the wet, i get the horrible smell of a burnt clutch, any ideas whether this is going to be a problem now. (please no posts about "its not a drag car, no need to do this" because this is all i can do right know, no license, and i do plam to track or autoX or something with turns as soon as i can, all i do right now is cloverleafs and entrance/exit ramps. :D )
 

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Try taking the DCCD out of auto and bias it all the way rearward. I have heard from other drivers that this helps with clutch bogging/sticking issues...
 

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That's hard to do for us folks that have seen what happens to WRX and 2.5RS transmissions when you just "dump" it. :D
 

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The tranny is bullet proof!
 

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Discussion Starter #6
thanks for the launching advice, confirmed it at my friends house with a long driveway, but i was more concerned about any long term effects from a half dozen launches with clutch stink.
Thanks Again
 

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I tried launching at approx: 4000-5000 RPMs with the DCCD on auto and on manual at all the different settings. The burnt clutch smell was present in all cases, but not as bad with DCCD on manual with control dial all the way back. Can't tell which is faster, until I experiment on the track later.
 

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western mass sti

:eek: I launch at redline (7000rpm) and when i dump the clutch in i'm at approx 5000rpm. I don't really have a smell of burnt clutch though... is that a problem?
 

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maxwolfinger said:
...let the clutch out really fast...
"Fast" is relative!

If you don't literally pop the clutch...as in hold down and slip your foot off the pedal sideways...you will run the chance of heating up the clutch during the release process enough that by the time it is fully engauged it cannot provide enough friction to stop it from slipping...ie huge clutch smoke show.

See the instant you give the clutch a chance to slip it will start to heat up. As the clutch disk heats up it provides less friction. If you manage to slip the clutch long enough...and I am talking about fractions of a second...it will heat up enough that even when fully engauged the clutch mechanism will be unable to clamp hard enough to generate sufficient torque to spin the wheels. The disk will be like a greesed plate...spinning more and more with less and less torque transferred, no matter how hard it is squeezed to the flywheel. It is a vicious cycle...slip, heat, less friction, more slip, more heat, even less friction...

The key is to release the clutch fast enough that by the time the pedal is released the wheels are broken loose...or broken ;)...thus the clutch and flywheel are turning together as one with no slippage. When there is no slippage, there is no heat, and your clutch lives on for yet another day!

With that said, there is allways the possiblity that if the clutch drop was fast enough you could send a shock load through the drivetrain to fail the weakest link...whatever it may be...tranny, diff, axles. With 300 HP, and with what I've seen people do with theit STi's, my feeling is that the clutch will remain the weakest link.

...oh, and careful trying it with R-compounds, on a hot day, on a heavily rubber imbedded track. The tires will take a shitload to brake loose, and chances are something else may give!
 

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Discussion Starter #12
MANNNnn.. what the heck is rattling.

...oh, and careful trying it with R-compounds, on a hot day, on a heavily rubber imbedded track. The tires will take a shitload to brake loose, and chances are something else may give!
speaking from experience?
 

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LaZy4zNbOi said:
:eek: I launch at redline (7000rpm) and when i dump the clutch in i'm at approx 5000rpm. I don't really have a smell of burnt clutch though... is that a problem?
thats what I was thinking... I can dump it from 5500-6000 and if I let it out slowly but quick enough, it wont smell like clutch burn. I guess Im doing it right? or not? or what?

Robert~
 

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maxwolfinger said:
...oh, and careful trying it with R-compounds, on a hot day, on a heavily rubber imbedded track. The tires will take a shitload to brake loose, and chances are something else may give!
speaking from experience?
...I did a nasty clutch launch at a strip once with an ITR I had before the STi. Fortunately I was quick to realize that the "sweet slippage" wasn't comming from the tires, but the clutch. :eek:

...so I can only imagine the possiblities with the STi! :wink: :D
 
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You should not be burning your clutch at 4500 rpm. If you are confident you know what you are doing, you should take it in to be looked at. Otherwise, assume it's driver error, :)
 

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The clutch is a bit overwhelmed by the torque on this car. It was designed for the 2.0 liter in mind and at 300 whp it is definately overtaxed on my car. Dumping it will solve the problem but at the expense of transmission and differentials. Twin plate Exedy carbon clutch is available currently and ATS Twin and Triple plate carbons are in development.
 

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Ever notice that upgrades for the WRX (not sti) clutch plates say that they're not suitable for the STi? That's because it's not using the same clutch. If anything, its using the same one as the 2.0 liter STi in japan, which is 280 bhp, and shouldn't make much difference.
 

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the usdm doesnt use the STi clutch from 2.0 ltr engines, it has its own which is why some are being developed
 
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