Hey guys,

My OEM clutch just went last month (with about 50K on it), so I decided on putting in a racing clutch to support my engine/TT build-out project currently underway with Hill's Garage in Baltimore, MD. I went with the OS Giken triple-plate ceramic clutch, based on Sam@GTM's strong recommendation. I originally was going for a Carbonetics, but Sam said carbon discs take too much time to "warm up" and that I'd be slipping in colder conditions, especially since I live in Maryland!

Anyway, regarding the new clutch, I can go into the gears perfectly and when I'm at speed or moving shifting is pretty easy. I feel very smooth, accurate transition of power from the crankshaft to the wheels. It feels strong and so so smooth compared to OEM (as it should!)...

However, I am having extreme difficulty timing the release of the clutch pedal with the throttle when going from a dead stop. There's absolutely no play or slippage when engaging, I used to have a window where I could release and start accelerating but now it's like an on/off switch. I have to hit it perfectly, and even when I ease SO SO SO gently and feather the throttle, the car jerks violently a few times and then finally goes. I have to literally walk on eggshells to get going from a stop and even then it's a painful jerky experience. Hell I even have to disable VDC to make it less violent!

I am seriously hoping this gets better as:

I get used to how it engages
The clutch's mechanical components break-in and mate to each other

Is this near-inability to get into first gear completely normal and expected with a new racing clutch? As it stands right now, I am completely unable to get a quick start from first gear. It's a slow, tedious, and jerky process. Even race cars need to get a quick start off the line. Right now, I start off like a retarded turtle...

Any advice or experience is appreciated, guys!

Thanks,
B

 

Please realize that the information I provide comes as a result of experience and knowledge relative to clutch function and performance as well as the manufacturing processes that go into producing these parts. My initial thought is that you bought a "racing clutch" for what seems more like street use, and the result is less drivability. The OS Giken triple-disc uses a fairly aggressive bonded carbon-semi-metallic material. These discs are very thin (as a result of the limitation of space under the cover) and this assembly is very light making smooth acceleration from a stop more difficult.

Ultimately, as you get more used to the engagement you become better able to leave cleanly. The down side to this is that the normal response to chatter (which is the shuddering that you reference that occurs during engagement) is to slip the clutch, in hopes that this will smooth out engagement. The results from slipping the clutch are actually contradictory to this assumption; meaning that riding the clutch for smoothness will induce more chatter. Get out of the pedal more quickly and you can reduce the time spent in the engagement window allowing for smoother acceleration from a stop.

The thinness of the discs I reference earlier also leads these units to have a shorter wear-life than assemblies that utilize thicker discs. Slippage, as a result of riding the pedal for smoothness or overpowering, leads to faster wear—so you need to adapt your driving style in an effort to get as much life out of the unit as possible.

This information is not intended as a slight to OS Giken, as the characteristics mentioned are similar for the majority of clutches of this type. That being said, had we talked before your purchase I would have strongly recommended that you opt for a clutch that is more suited to high capacity and daily drivability—trust me there are options available that allow for both of these seemingly contrasting characteristics to coexist. If you find yourself in need of something more drivable let me know and I will be happy to assist you with recommendations. Thanks,

 

I had a twin-plate exedy in my last car, and driven many triple plates. They are definitely not for the faint of heart in daily driveability.
The Twin-plate would end up in the same predicament as you during driveability. After it's initial break-in period it was much easier to drive, although still "semi-streetable" as I would catch myself stalling it or rough off a dead stop if I wasn't paying attention.

The triple-plate for your case seems a little over the top, I would have said a Twin-plate would have been fine, especially since you don't just race your car.

Either change it, or get used to the On/Off, since any multi-plate clutch sprung or un-sprung is not the easiest to drive all the time.

 

Thanks guys. I was told by Sam that I would not be disappointed with this clutch. He claims to have it on his car and said it will probably be the last clutch I ever buy. I wanted a clutch capable of 800-900 ft/lbs. so if I upgraded to the GTM GT35r turbos in the future, I'd be able to keep the clutch as it would hold the power well.

I guess the good news is that this is normal/expected, and will get a bit easier as it breaks in. Thanks for all the info and experience guys. I did notice that it seems to take off more smoothly if I "launch" and release quickly vs. a normal, slow clutch pedal release. It's almost like I have to run it off the line for now until it breaks in a bit!

So I suppose now I just gotta focus on breakin this bad boy in. Thanks again...

-B

 

Yep that's what I did during the break-in launched it pretty much every time. I'm sure everyone thought I was racing everywhere...ah well!

Enjoy it, I personally love multi-plate clutches.

 

I just put on some new rear tires and it seems to be less jerky. Also, it's definitely less jerky with the VDC turned off as well. The built-in traction control was interfering since the take-off was not very smooth and the wheels were spinning a bit. I'll let you guys know how this things breaks in!

 

I run an OS in my car and the first 300-400 miles the clutch was either on or off. After the 400 mile mark the car has become noticeably more compliant. Still takes more revs than a non integrated set-up for sure, but the harsh shutter and engagement has softened considerably. Only times the car can become a bit too aggressive is after lengthy hard runs in warm temperatures.

 

Yeah, even after 200 miles or so it's already starting to get a bit easier to find the release point without jerking too much or stalling. Don't get me wrong, I'm still hesitating, and stalling, but it's happening less and less.

 

Is this the first car you have had with an integrated set-up? It is pretty run of the mill in comparison to others I have had and driven.

 

Hey man,

Sorry if it seems newbish but I'm not sure what you mean by "integrated" setup? Anyway, this is the first time I've run a high-end, racing clutch, and, for that matter, any non-OEM clutch period!

It does seem to get a bit easiereach day the more I drive it. I'm still a bit jerky on take-offs and stall lots but it does seem to be decreasing slowly and surely...

Thanks again for the info!

 

Well, if you haven't had a non-oem clutch then it is safe to say it is the first integrated.

One tip I will offer is when getting going in 1st from a stop rev the car up to 2000ish and disengage the clutch as the rpms drop from there down to about 1700 and it is generally a bit smoother. Might want to try going to 2500 and catching it on the decline at first. This should help in getting the car moving without the shutter that makes the car feel like the wheels are going to come flying off.

 

LMAO! You explained that to the 'T'! Sounds like you've been down this road many times before. I'll try out your tips tomorrow...

Thank you!
-B

 

I had a tilton twin in my gt37r honda before I put the OS in this car and both will bite you directly in the *** if you don't engage it with "love". The OS is light years better on the street, but it the shutter can be intense if you get too cute. Anyone who hasn't driven an integrated set-up has no idea how intense that shutter is. Feels like the engine and trans are just going to fall out of the car.

 

What's the life of this clutch or these types of clutches in general? I know they're meant for racing, and not really daily driving. What's been your guys' experience with how long these things last? I dropped ~$2100 on this bad boy so I'm just hoping it'll last at least a few years! My previous OEM clutch lasted 50K miles and 2.5 years...

Also, if something starts to go on this clutch (discs, plates, etc.), are the individual parts replaceable or does the whole clutch need replacement? Just trying to figure whether I can just drop in some new plates if they wear out in a year or so...

Thanks!
B

 

Honestly, I am not sure with the OS, but my Tilton needed to be re-done once with new clutch disks. I guess it is going to depend on your driving style, amount of track abuse, and overall mileage put on the car. I would say it is plausible that at some point you may need to replace the disks, but I would imagine you could get 2+ years before having to worry about it (unless you regularly track your car and/or put a ton of mileage on the car).