I was initially thinking to try the Spec clutch but decided on Clutch Masters as they had a lightweight flywheel application for the Slowtra whereas Spec only had the clutch kit (clutch plate and cover). Picture of the clutch and flywheel in the box. I don't really dig white but guess it doesn't matter once everything is covered up by the gearbox bellhousing. The QG18DE uses the same clutch (not flywheel) as the FF SR20DE so there are plenty of choices available.
The clutch alignment tool is on the top left hand corner of the packaging with the clutch release bearing on the top right hand corner. Removing the transparent wrap revealed the clutch cover and clutch sitting on the flywheel.
Clutch Masters make several "stages" of clutches with the FX100 being the lowest stage or stage one and primarily for heavy duty street use. Then there is the FX200, 300, 400 all the way to 500 race only. There is also a twin plate but not avail for the Slowtra unfortunately. I got the FX400 in lieu of my expected power and torque. The FX400 is Clutch Masters ultimate extreme duty street and/or road/drag racing clutch and is the most streetable clutch a sane person would use for daily driving. The FX400 is available in both 4 or 6 puck/paddle with the higher puck count being the less aggressive setup. I'm a wuss hence decided on the less aggresive 6-puck clutch (Part number: 06-057-HDCB6). Having driven Exedy 3-pucks before where the all or nothing feel and the inability to slip the clutch especially during Penang's famous traffic jams was a royal PITA. On top of this due to the thin material and low puck count the clutch had a limited service life before it was due for replacement.
Picture below of the clutch cover's pressure plate. The FX400 uses what Clutch Masters call the Power Plus 1 Pressure Plate/Clutch Cover.
The 6-puck clutch disc features a sprung hub making it more streetable than solid hub clutches. Clutch Masters uses ceramic for the friction material. I would still expect this clutch to chatter slightly during first or reverse gear. Holding capacity is increased 170% over the stock QG18DE/RS5F70A clutch and even more over the smaller diameter QG16DE/RS5F30A clutch.
Clutch disc sitting on the clutch cover/pressure plate.
A lightweight flywheel enables you to accelerate faster and the effect is much more than a lightweight crank pulley without the potential reliability risk to the engine's lower end components and bearings. This helps to reduce turbo lag in turbocharged engines. Clutch Masters produce both chromoly and aluminium flywheels but only aluminium is available for the Slowtra. The aluminium flywheel is a a two piece unit featuring high carbon steel replaceable friction surface and oem steel steel ring gear. The aluminium material is billet 6061-T6. Unlike ten years ago when I upgraded the SP's flywheel, aluminium flywheels nowadays are generally reliable and stronger than the stock steel flywheel and with no risk of stress related failure. No need to worry about your manhood and other body parts getting sliced up by an exploding flywheel. Clutch Masters claim their lightweight flywheels are typically 50% lighter than stock but I have not weight my stock flywheel nor the new Clutch Masters unit hence cannot verify. Will do so when I install the clutch and flywheel.
Picture below of the Clutch Masters Billet Aluminium Flywheel (Part number: FW-727-2AL). The high carbon steel steel friction surface is the darker coloured section of the flywheel.
I am still waiting for several components for my "new" gearbox to arrive as the clutch and flywheel will be installed together. Still deciding if I should install my "new" gearbox on my puny QG16DE first or wait till my "new" engine is build.