str8dum1

iTrader: (11)

So since my stock clutch was completely trashed from my numerous track days, it was time to upgrade. I wasnt very thrilled with the idea of a 6 puck and its on and off engagement in stop and go traffic. Plus the trq ratings on all those 'stage 4' level combos out there by various vendors might not be adequate in the next year if I decide to build the motor. I definately didnt want to underbuy my clutch.

So in comes the Spec Super twin (http://www.specclutch.com/cars/Infin...004/Super_Twin). Its a twin disc clutch with organic pads rated at a whopping 900 foot pounds. It comes with a light weight aluminum flywheel with a billet contact surface. Mine weighed in at a scant 11.6 pounds.

Best part was the price, under $1100 compared to any other twin disc on the market, it was hundreds less.

The install took about 4 hours on my back using jack stands and an assortment of hand tools.

Today was the 1st day I got to drive, and wow, it feels just like stock. I was really expecting to have to relearn how to shift, based on almost every light flywheel/ high trq rating clutch, but this is super smooth. You can still feather it into gear and its not super grabby.

Overall very impressed and think this is a great alternative to the $$$ carbonetics. Will it hold 900 ft pounds, dunno, but I would think it would be perfect for the 600 whp thats becoming the standard on this forum!

TrackPack

iTrader: (1)

very nice! I'm glad you tried this out, I've always thought that this would be my next clutch, but no one seems to use it..

bbs350z

iTrader: (85)

theres a few members on here, including a member who was running nitrous + meth on the greddy kit, and did multiple pulls around 850whp

im using it, and will write a review once i get my tune (shooting for an 800+rwhp high boost map )

TrackPack

iTrader: (1)

AWESOME! I didnt know there were that many members here that were putting it to the test. Is every one on the organic discs? Because I believe there are multiple stages but I would prefer the most street able.

marra23

iTrader: (8)

seriously considering this.

Quamen

iTrader: (14)

Spec is a wonderful company!! They sponsor our Porsche 928 each year and the funny thing is that we have had the same Spec clutch in for quite a few years without need for replacing it. Go figure.

This is what I will be looking into this year when I break into the 500whp club and my FX400 decides to go.

Dynosty

iTrader: (27)

I really hope they have corrected the problems by now, but here is my take:

I know of and have personally experienced multiple cases where the VQ35 spec twin disc clutch (st trim, 1200tq rating) does not work properly and gives trouble. Spec will bs that they haven't heard of any problems, but the reality is they are quite aware that there are issues.

In fact, here is an email I received 4 days ago...
"I had a ton of issues with the SPEC clutch/flywheel. FYI... I don't think SPEC is very knowledgeable on the VQs. We contacted them and they had no idea what we were talking about. Once it was installed, I was having a hell of a time shifting at high RPMs. I thought the last thing would have been the clutch bc it was brand new. So I bought a new CD009 tranny, new clutch master and clutch slave and nothing changed. I re-installed my short throw and still no change. I adjusted my clutch pedal and it started to help. All in all, the SPEC clutch requires more clutch travel to disengage it. They do not mention this and because of this, my shifts around 6500 to 7000 RPM are slower because of this issue. The tell tale sign is that I can park the car on level ground, push the clutch in and rev the car up and around 6500 it starts to roll forward. Needless to say I have spent a lot of money and time trying to determine this. Thats why I haven't been able to get down there. I do not recommend SPEC for anyone."

TrackPack

iTrader: (1)

crap.....I was hoping no one was going to come in with something like this....
spec has screwed up in many applications over the years and because of that they have a pretty poor rep, and no one around me would run one. But I was really hoping this one was sorted out.

rrmedicx

iTrader: (54)

Just curious but do they use the same OEM throw out bearing? or possibly a smaller one like the OS Giken set-up?

thom000001

more power too you and changing the clutch on jackstands.

Another option for 600rwhp would be what I have now, the DXD Southbend, and its even cheaper (single disk).

tom

str8dum1

iTrader: (11)

edit: i just tried pushing in the clutch while revving to 6500+ and the car didnt move at all but that might not indicate if it stick when shifting under load.

I do agree, it does take a lot more throw for it to disengage. we iniitialy thought it was a tight pilot bushing grabbing the input shaft, but all I had to do was adjust that threaded rod behind the clutch pedal.

Since the clutch wasnt that used here on the Z's, i had to do all my pre-purchase research by reading the Vette and Supra forums which was pretty much positive (except some Supras bc they were changing from to a hydraulic setup)

The throwout bearing is definitely much bigger/thicker though than the stock one. i wish I woulda taken a pic of the difference. Its obvious to the naked eye that the Spec throwout is almost 1/4" thicker.

Granted the clutch is still new, i havent tried to shift at redline so I cannot verify or deny the hi rpm shift problems. Mine is a different model than Hal posted, I only have the SS model.

Thom: I saw the southbend one, but was hesitant because of all the single disc, must relearn how to drive, car almost rolled into the car behind on a hill startup, etc stories. I was actually quite easy with the jackstands.

leg killa

iTrader: (6)

+1....did it on jack stand..good job..takes me the same amount of time but on a lift..lol

Fixxxercask

iTrader: (21)

Hey all,

I was the one that wrote the email to Hal about the clutch. I am glad to hear that not everyone is having this issue. I went to the track this weekend (drag strip) to try and run and my times were about 4 tenths slower because of the slow shifting due the clutch problems. It seems like yours is working great. Thats good to hear. I am taking mine back out and getting a new clutch and flywheel.

leg killa

iTrader: (6)

just a question..i heard that you dont want a lighter flywheel when going FI..you get faster throttle response but will drop out of boost just as quick...true?

leg killa

iTrader: (6)

i ask this because i plan on going FI within a couple months and i run a ACT streetlite flywheel..12 lbs i think..just wondering if im to have to lose it

Jeremy@Altered

We had one that was installed brand new and within 500-1000 miles it started making a really loud clanking sound. When we took it apart we realized that the holes they made for the flywheel bolts were way too big. The only part of the bolt that was holding the flywheel on was about a 1/64th of an inch all the way around the head of the bolt. The flywheel is made out of aluminum and quickly tore loose from the bolt and moved back and forth in the bolt holes.

I will say that SPEC was nice enough to replace it for free but customer had to eat the shipping. Before anyone installs one, make sure that the holes are not the oversized V1.0 ones or you will have this same issue.

str8dum1

iTrader: (11)

the bolt holes seemed tight on the bolts, so hopefully no issue there. everything tightened down to 93 ft pounds, which did seem like a alot on those lil torx bolts. I read something after the install about putting washers under teh torx bolts, but there were no washers included nor instructions, so hopefully it will be fine

i'll post back after i hit the track on thursday.

Chef-J

iTrader: (58)

Are you giving a break-in time?

Looks good from pictures, hope you like them. Can you hear any chatters?

str8dum1

iTrader: (11)

ya 500 miles of city driving.

i cant hear anything over my exhaust, so i dont know.

Nexx

iTrader: (41)

+1, i want driving my Z to be fun again.. the FX400 really pisses me off. holds gobs of power but its not daily driving friendly at all.