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JWT’s clutch disc is bigger, 250mm in diameter vs the stock 240mm. This gives more surface area for friction material and gives a bigger moment arm to the disc vs the crank allowing it to hold torque better. Like stock, the JWT uses a semi metallic friction material and a marcel spring under the friction material to help cushion the shock of clutch engagement. These features give the JWT clutch smoothness and help protect the drivetrain by reducing shock loads. The JWT clutch disc features a sprung hub with a center stamped out of heaver gauge than stock steel with more positive than stock containment of the hub springs. Hub failure is the most common issue with high performance clutches and the JWT’s beefed up center is going to be less likely to fail. Jim Wolf Technologies clutch has about 50% more torque capacity than stock. Because the JWT clutch gets its increase in torque capacity from more clamping pressure and a bigger diameter disc, it should be pretty smooth in operation. Because of the bigger diameter and beefy hub, the JWT clutch disc weighs 4 lbs vs the stock 3. This means in total the JWT clutch and flywheel weigh in at 34 lbs, a whopping 17 lbs lighter than stock.

Stock Nissan 370Z clutch disc
JWT heavy duty Nissan 370z clutch disc
The stock 370Z clutch disc is starting to glaze and slip after just a few hard launches when we were filming video.  The Jim Wolf Technology clutch disc is 10 mm larger in diameter and has a higher metal content.  This increases burst strength and helps the disc operate better at higher temperatures.  The stock disc is one pound lighter than the JWT part mostly because of the larger diameter and the stronger hub of the JWT disc

 We had Howard and Ritchie Watanabe of Technosquare install the JWT clutch and flywheel on our test 370Z which they did amazingly fast, in a little more than an hour. On our test drive we noted that the JWT clutch is buttery smooth in engagement and overall operation. This is perhaps the smoothest high performance clutch we have ever felt, perhaps even smoother than stock. The clutch pedal effort was hardly changed as well. On the road we were amazed at the difference in feel of the JWT system over stock; the car felt more snappy and lively, like it wanted to go. Much of the lag was gone from the throttle feel and the car accelerated noticeably harder, especially in the lower gears. Best of all the SynchroRev system still worked flawlessly. We did note that the autorevving feature revved the engine slightly more sharply, but only a trained observer would probably notice.

Technosquare howard watanabe nissan 370z transmission install
Technosquare's Howard Watanabe had the transmission back in the car unbelievably quickly

There are some drawbacks to the light flywheel. The worse issue is that the 370Z’s signature input shaft rattle noise was worse and you could definitely hear it below 2200 rpm, where before it was very hard to hear. We would like to point out that every manual transmission car we have ever driven has made input shaft rattle to one degree or another and that it does not harm your car or mean that the life of any part is going to be reduced. When you turned on the radio, you could not hear the shaft rattle anymore so perhaps that’s a good cure for the issue! The car feels a little more jumpy in parking lots and low speeds making smooth date-impressing driving a little harder. Vibrations were also slightly increased in general. Because of the increase in NVH, if you are picky or a sissy and feel that the 370Z is barely acceptable as is; you probably are not into performance and shouldn’t consider this.

Jim Wolf Technology Nissan 370Z lightweight flywheel dyno chart
Are dyno results of the Jim Wolf Technology lightweight Nissan 370Z clutch and flywheel yielded impressive results, 6 whp and 4 lb/ft of torque nearly across the board.  This is better than we expected!

Next we strapped the 370Z to Technosquare’s notoriously conservative Superflow chassis dyno to see how much power got freed up by eliminating those pesky 18 lbs. We were surprised to see that the 370Z belted out 6 more whp and 4 lb ft more torque, largely across the board, a gain that gave mucho area under the curve making JWT’s clutch and flywheel one of the biggest overall power gains of all the single parts we have tested so far.

With hardly any negative issues, we recommend JWT’s clutch and flywheel combo highly (unless you are a girly man).



Jim Wolf Technology

Technosquare Inc

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# Steve
Wednesday, August 05, 2009 4:32 PM
I've been really pleased with my JWT FW/Stage 2 Clutch on my V35C's VQ35DE, it really opened up the rev happy on the motor esp now with ECU changes. Mine was an older '04 and was capped at 6850 cutoff, I raised to 7400 and it's smooth to 7200 easily. It's so responsive w/o the boat anchor and minimal chatter at idle.

Curious to see that the dual mass FW for the 370 weighs in a 32 lbs, same as last gen, but the new JWT weighs in at 16, which is heavier by 3-5 lbs than the VQ35 version?

Larger surface area maybe?

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