So I picked up my coupe today after install of an OS Giken STR dual clutch and integrated flywheel. I chose the OS, cuz it was marketed as being extremely streetable, durable, w/ similar pedal effort to stock.

I was expecting some noise and or vibration b/c of the lightened flywheel (as everyone who installs one should be), and also having to "relearn" to drive the car and or deal w/ break-in issues.

First off, the tech said everything installed perfectly and a couple weeks ago, I swapped out my factory rubber clutch line for a nismo ss line w/ motul fluid flush.

Started up car, turned on ac, turned off radio, rolled down window. Did not feel any added vibrations and maybe there is a little extra noise at idle, but I already have gotten used to added noise w/ headers and at idle. It is interesting to note, that on the trip home, I experienced zero chatter or extra noise/vibration at idle, except right before I turned off the car (and this did not last a few more seconds). I really hope this continues to be the case at idle!

BUT, there is definetly that infamous cement mixing noise when accelerating from low rpms (but this is only during a small section of the rpm band--maybe b/w 1800-2000. But, I was able to pretty much adjust my driving style to minimize the noise by keeping the rpm's above 2k, which I think is well reasonable for daily driving).

AND, (I really hope this is a break-in issue)--Cloud where u at?--1st gear is ridonculously grabby and it is so hard to get the car moving from a stand still w/out experienceing shuddering or overreving to get it going. I am also still getting used to shifting faster as a result of the rpms dropping faster, just as they climb faster w/ the lightened single flywheel. The engagement point, surprisingly seems to be almost just as high as stock, and the pedal effort is the same, if not a little easier. There is also less play. But so grabby in 1st

I'm trying to break-in the clutch properly, but it's so hard to drive smooth right now. Anybody know if the grabiness will improve as the clutch breaks in w/ the pressure plate and flywheel? I don't want to have to launch every time I am stuck in traffic. Anybody have any suggestions?

After 1st, however, shifts are smooth, crisp, and precise. Shifting when driving feels great No more notchiness and for some reason, the shifts seems shorter?. So, I really hope the grabiness gets better when the clutch breaks in, or I adapt better to the setup, otherwise I feel like I lost a lot of driveability w/ this mod. But, I'm keeping my fingers crossed.

If anyone could chime in on whether the grabiness/shuddering will get better as the clutch breaks in, it would be appreciated

 

It will get better only to a certain degree. You'll notice yourself revving before letting go of the clutch to start moving from a stop and that can't be helped...

 

^^I kno what you are talking about cloud. I seem to be getting a little more used to the setup, but it's still kinda weird not being able to just easily roll off withough revving. Also, definetly get some cement mixing noise at idle, but its not very loud (although I amost wish I had installed the ORC b/c of its "silent" option). Kinda sucks I can't really experience the positives of it until after break in.

But it's a lot more natural to smoothly shift once moving now as I always actually pissed that the rpms dropped so slow w/ the stock setup. I'm gonna give it some more time, but it's definetly the only mod that I have done, that I have said afterwards, maybe I shouldn't of done that. lol. oh, well, I got a new 409 and the stock setup w/ 12k on it in storage, if I want to change, but the install cost is totally poop...

 

Umm, I'd say go with an organic clutch the next time. Differences in performance when racing is another matter but I think that the confidence boost you get from feeling connected with an organic clutch is priceless on the streets.

 

it's not a break in issue....every integrated single disk clutch, no matter what car is very very grabby. It's something you can either get used to, or not.

 

welcome to having a carbon clutch.

 

I got used to it Thanks! It's only a little difficult in first, but I am getting better at it and the pros (faster acceleration, increased holding capacity, super smooth shifts (After 1st of course lol) really greatly outweigh the negatives (grabby in 1st, slight chattering at idle) imo. And its a dual clutch disc.

 

It's actually a cerametallic clutch (sinthered bronze) I believe.

 

Good write-up so far. Let us know how your doing with the clutch now when you can. I am thinking of buying one similar.
Thanks.

 

No probs. I think the tech made a little adjustment after my HFC's were installed, or I'm just getting more used to the clutch/flywheel combo. Make no mistakes about it, w/ a friction material such as sintered bronze (or pretty much any material besides organic), especially in an integrated unit, by its nature it is grabby in first. It is easy to have the car "studder" if not paying attention from a "roll of".

That being said, all around I am really, really, really pleased w/ the setup I've already put 600 miles on it, so I've been running the G harder and my driving experience is really nice! Pedal feel is very similar to stock (maybe a tad bit firmer--but I think this is a good thing). The OS Giken STR for the z33 is a dual-clutch so it can handle a good amount of power 500+ easu. Since I'm NA and don't plan on seeing those kind of numbers anytime soon, it's still comforting to know that when I do go F/I, it'll be able to handle that.

Especially w/ the HFC/mrev2/space/intake, the lightened flywheel really allows the rpms to get up there fast (especially in the first three gears). I'm not sure on the actual weight of the flywheel, as I never took the integrated unit apart to weigh the flywheel alone, but just in seeing how the rpms rise and fall--I find it to be ideal--rev matching and smooth shifting are a lot easier now then w/ the oem setup.

Of course, I do hear the occasional weird noise goin on under there in the transmission area. Lots of "pops" (I assume that's the springs at work, acting as a dampener), the occasional clunk, and of the course the "cement truck" noise at idle--however this is not always there interesting enough--but there is a noticeable sound b/w 1-1.3k. However, I have found it easy to adapt my driving style to the new setup. Also, the exhaust note pretty much drowns out that noise--can't wait for my exhaust

I can tell you that from looking at the STR and getting other techs to take a peek at the materials and quality of it--It's practically indestructable--so durable--very streetable. And just after a couple hours of rough driving--it took it like a champ and was asking for more--the transmission would break/fail way before the STR would.

Overally, I'm very pleased w/ my choice. It wasn't the easiest to get used to at first (but it was really just like learning to drive the G over again). After 2 weeks, I pretty much had it down. It's actually kinda a pain to go slow now--the car feels like it wants to be pushed--or maybe it's just my foot on the pedal

 

Glad to hear it is working out. I am going to have to check out the web re: info about this clutch. Unless there are multiple varieties of this clutch, perhaps with different compounds, I thought they were good for up to around 8-900 rwhp?

I say this because, it is this clutch that they race with in Japan, if I am not mistaken.

Still nice write up. Good Job! I appreciate the detail and time in explaining how it worked out.
Thanks.

 

you can't use a single disk clutch on your car Randy, unless you have no plans for forced induction down the road

none of the OS Giken units will handle 800-900 whp that I can tell you - you'll need a very very very extreme clutch to handle that sort of power

I just put in the OS Giken single into my car (since I am not ever going FI), after having here at the shop for a couple years sitting around lol. It is extremely grabby, and extremely noisy, but the car definitely feels "lighter on its feet" due the weight difference from it to stock (this weighs just about 50% of the stock clutch/flywheel). If I were to actually buy a clutch, this is not the one I'd personally pick, since there are ones far quieter that would have been more than sufficient, but since I didn't pay for it at all, I'll run it

 

I thought he was describing a twin. Nevermind.
Good catch adam. Thanks.

 

I think he is, but even a twin is good for maybe mid 500's at the wheels if you want any sort of longevity. To get to the upper echelons of power, the 700 and up, it's going to take either a really obnoxious twin disk (ie tons of clamp load which means a very nasty pedal and solid hub), or a triple (even more expensive)