TEIN Suspension Upgrades & More - Mono Flex - Sport Compact Car Magazine

The pourable urethane foam expands to eight times its liquid volume, meaning the 16 pound net weight size kit is more than enough to handle the entire 240SX chassis. Handling the foam itself isn't difficult at all, but proper prep is a must. The foam is nearly impossible to clean off once hardened and sets very quickly. Before mixing and pouring began, Project S13's interior was completely covered in a drop cloth, newspapers were placed underneath, disposable work clothes were worn, and bits of duct tape were placed next to every orifice that we would be pouring into, so that the expanding foam could be captured inside instead of bubbling out. We also made sure to tape up the backside of the lower seat belt holes in the rockers, so that the foam didn't fill up the threads for the mounting bolts.

Although we don't have any exact stiffness increase percentages, a simple garage measurement yielded a stiffer chassis with a 1/4-inch front and 1/8-inch rear increase in frame to ground height as the car was jacked up at the front left, with a floor jack saddle height of 10.75-inches. Driving the car is also a revelation, with less creaks going up driveways and a noticeably smoother ride over broken pavement.

With Project S13's chassis now highlighting the suspension's movements, we began to become dissatisfied with the drift setup for our purposes. Project S13 arrived at our doorstep equipped with the generations old TEIN Type HE Drift Spec Winding Master coilovers. Although we want to be winding masters as much as anyone else, the suspension was built with drifting in mind. This meant that lots of compression valving was the name of the game, which is useful for quick weight transfer and Scandinavian Flick-type feint moves to initiate drifts. But Project S13 rockets over the undulating pavement and curbing of Buttonwillow Raceway, meaning that a damper resistant to compressing will shock the chassis over rough surfaces and cause the tires to lose contact with the ground.

Everything you'll need to easily fill your car with stiffening urethane foam: 2 pound density injectable kits for the pillars, 8 pound density pour foam for the rockers, measuring cups, funnel, paint mixer, drop cloth, and gloves. If you're feeling adventurous, or have access to a rotisserie, we highly suggest the use of 8 pound or higher foam in the pillars. For strength, you'll only really need to fill the pillar joints and corners, but getting the liquid to stay and expand in those spots is very difficult.
Everything you'll need to easily fill your car with stiffening urethane foam: 2 pound dens
After pouring the two liquids together in a 1:1 ratio, you have mere seconds before it hardens and becomes un-pourable. Plan ahead and make sure your entire chassis is torn apart and prepped. Notice all the bits of duct tape that we have ready to enclose the foam in the rocker. We also added our large plastic drop cloth into the interior shortly after this test pour.
After pouring the two liquids together in a 1:1 ratio, you have mere seconds before it har
The urethane foam expands to eight times its liquid volume, filling up any pillar or panel with ease. Just be sure not to get any on your paint, seats, or carpet - it'll never come out. Also, make sure that you don't capture anything that you'll later need access to such as power cables, nitrous lines, or seat belt mounting holes.
The urethane foam expands to eight times its liquid volume, filling up any pillar or panel

TEIN's latest Mono Flex coilovers use monotube dampers (inverted in the front), spherical upper mounts, separate adjustable ride height, and 16-position combined rebound and compression dampening adjustment. Despite having more rear spring rate (7kg/mm versus 6kg/mm), these are more compliant than the old Type HE drift coilovers. The Z32 rear lower brackets that we sourced last time, to fit 300ZX rear aluminum spindles, will work with the Mono Flex system as well.
TEIN's latest Mono Flex coilovers use monotube dampers (inverted in the front), spherical

After pulling the coilovers and making a trip over to TEIN USA for a damper rebuild and revalve, we were told that the Type HE's twin-tube damper design was nearly a decade old. TEIN's internal damper piston and shim designs have changed dramatically since and the Type HEs could be rebuilt, just not with the modern internals. We ended up leaving with a lighter wallet and a set of TEIN's latest Mono Flex coilovers.

The Mono Flex system is based around TEIN's newest 16-position adjustable monotube design. The monotube damper features a larger piston than TEIN's twin-tube designs, displacing more shock oil per stroke and thus giving finer damping control as well as greater heat dissipation. TEIN also inverts the front strut monotube for a decrease in unsprung weight. During installation, we maxed out the front upper spherical bearing-equipped camber plate by shoving the strut all the way in. To our surprise, the front lower strut mounting bolts were 14mm in size, while the Mono Flex lower mounting bracket had 12mm holes. We guessed that Project S13 was equipped with S14 front spindles but didn't think much else of it and drilled out the brackets to fit the bolts. We'll get to that one in a second.

After driving on the new Mono Flex suspension, we couldn't believe that the Type HEs came from the same company, regardless of the difference in production date. The Mono Flex exhibited a much more smooth and controlled ride, even on full stiff, with more precision than the HEs and better traction due to the tires actually being able to stay in contact with the ground at all times.