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Stock Nissan 370Z clutch vs JWT heavy duty
It is easy to tell the JWT heavy duty clutch at a glance, it is 10mm larger in diameter.  The disc has a higher metal content as well.  You can see that the stock clutch is starting to get glazed from just a few drag racing launches.  The pressure ring of the pressure plate is also starting to get discolored from the heat

Although this elaborate flywheel does do a great job of making the VQ37VHR one of the smoothest V6 engines in production, the heavy flywheel takes a pretty Åbig toll on performance, sucking up the engine’s power and slowing throttle response. The weight makes the throttle pedal feel like it’s attached to the engine with a slinky spring. Although we don’t like this, many drivers will purchase the 370Z just to have a sporting image and will never notice or care. These drivers will probably appreciate the smoothness and quietness of the dual mass flywheel.

370Z Stock Pressure Plate vs JWT pressure plate
The stock 370Z pressure plate on the left has an unusual self adjusting feature.  The diaphragm spring is pulled up the ratchet like ramps stamped into the cover by the springs on the top of the cover.  You can see the ramps here.  This keeps the freeplay from the pressure ring to the clutch disc constant as the disc wears, keeping the clamping load from decreasing with time.  The JWT pressure plate on right is a conventional heavy duty part

Other drivers buy a sports car for sports driving. These sorts of drivers want raw performance and lightning fast response to control inputs. They understand that a sports car will have a rougher ride, be louder, squeak, rattle and vibrate more than a luxury sedan and are willing to accept this to have more performance. Unfortunately Nissan must design a car that caters to this wide range of customers and compromises like the dual mass flywheel must be made to please the masses. Through superior engineering, Nissan has managed to make the 370Z amazingly refined without sacrificing much performance.

To get rid of the weight on the crank, we installed Jim Wolf Technologies lightweight flywheel and heavy duty clutch. The JWT flywheel is a lightweight aluminum unit with a replaceable and rebuildable steel friction surface for the clutch disc to ride on. The JWT flywheel also has a tough long lasting steel starter ring and most importantly a steel trigger wheel for the ECU’s revolution sensor, an essential element for the OBDII system, VDC and other systems to work correctly. The JWT flywheel weighs in at 16 lbs, less than half the weight of the stock part.

JWT’s clutch pressure plate has 1200 kg of clamping force, up from the stock parts 880 kgs of clamp. This increase of clamp force reduces the likelihood of the clutch slipping. When doing launches while filming video of a 370Z, we noticed that the performance of the stock clutch would degrade after just a few hard launches, so the 370Z can probably benefit from a beefier clutch even with a relatively stock engine. JWT has engineered the fulcrum point of the pressure plate’s diaphragm spring so that the pedal effort remains near stock despite the huge gain in clamping force. Moving the fulcrum also means that the engagement travel is lengthened making it easier to drive smoothly.

Stock Nissan 370Z pressure plate
JWT Heavy Duty 370Z Pressure plate
The complication of the stock pressure plate has a weight penalty.  The JWT part is 2 lbs lighter

The JWT pressure plate weighs 14 lbs vs the stock 16 lbs. This is because the stock pressure plate has an unusual self adjusting feature than moves the diaphragm springs fulcrum point as the clutch disc wears. This allows the pedal play and the pressure plates clamp load to stay more consistent as the disc wears. The diaphragm spring’s fulcrum can ride up on a series of ramps stamped into the pressure plates cover, constrained by springs, it positions itself to maintain the same air gap between the pressure ring and the clutch disc as the disc wears thinner. This complication comes with a weight penalty and is a potential failure point in a gritty and dirty area.

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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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