Reducing the Vibration, Upping the Performance

3 Oct

NISMO Rear Performance Damper 350Z

NISMO Front Performance Damper 350Z

There is an old expression in the sports car world “handles like it’s on rails”. In other words, a car that changes direction with such eagerness, authority, and minimal loss of energy, that its akin to a train following a track. To this end, people often go about fitting the stiffest springs they can, with the biggest possible swaybars, and rubber-band thick tires, hoping to reduce lean and roll. This works great on cars with huge sticky tires and lots of downforce (and thus high speeds), and ideally, driven on perfectly smooth tracks. While many try to mimic this on a street car, it’s usually not the case. Normal roads, and even many racetracks around the country are anything but glass-smooth. We’re genernally not running slicks or even R compound tires when we drive to the local diner or for a weekend blast down some backroads, and while we may have installed them on our cars, we’re not generally using dive planes, functional splitters and spoilers to their potential due to street-legal speeds. The same car that handles on rails is also crashing over every imperfection out there. Expansion joints might as well be speedbumps, uneven pavement akin to driving over road spikes. Geometry aside, these super stiff setups often compromise road car handling, more than they improve it. Chassis stiffening is not the same as suspension stiffening, and this is an often-overlooked feature. The chassis of the car is like the skeleton of a high rise building. It’s made of steel girders, because it’s the backbone of the structure. Similarly a cars chassis is the skeleton of the car: it supports everything else.

When NISMO developed the 350Z NISMO edition, mane shunned it as merely a cosmetic upgrade. The engine afterall was the same – but it wore a wildy out there (for a factory car) body kit – a long front bumper with low splitter, a long rear bumper overhang, and a decidedly “Fast and Furious” style spoiler. Delve deeper and you find what makes it so special. The chassis is fully seam welded. Meaning every joint, where 2 pieces of aluminum are bonded together, are full sealed. There are no gaps, there are no open joints. This increases chassis rigidity by a decidely large amount. This is one of the things people often do when bulding a race car from the ground up. To that chassis, Nissan fitted significantly stiffer springs (one of the stiffest out there on a road car) with heavy duty dampers. While the bushings and swaybars remained the same compared to other NISMO cars, the car was noticeably stiffer. But this is, afterall, a road car. While it is very much at home on weekend track days and club events, it’s designed to be a fun, sporting day to day means of transportation. Had it been left alone, it would have been panned for being too obnoxious on the road, too upset by the concrete jungle. To solve those issues NISMO worked with Yamaha to develop a Z-specific pair of body dampers. These attach fore and aft of the shock pointing points, between the 2 biggest “holes” in the chassis – at the front bumper, and in the rear spare tire well. Why there? When a suspension compresses and rebounds, energy is created, stored, and released in very quick succession. The stiffer the spring, the more aggressive the shock valving, the quicker this process happens. Which is why from inside the cabin, that uneven pavement can be downright punishing….whereas in a Toyota Camry, it’s just soaked up effortlessly. The dampers Yamaha and NISMO developed are designed to specifically combat these vibrations, without toning down the benefits that the spring/shock combo gives the handling aspect of the car. When you look at them out of the box, they are basically a strut brace, with a little shock built in. They compress and rebound, like a strut does. However they mount veritcally, whereas shocks mount horizontally. So they combat the natural vibrations the chassis will face when hitting potholes, uneven pavement, and normal bumps in the road. This minimizes energy losses, and lets the spring and shock more efficiently do their job, while keeping the driver comfortable, and thus confident, behind the wheel.

Think it’s still just marketing hype? F1 cars began using similar devices in the 2006 season. Or, just try it for yourself: we have. A 350Z with coilovers (pick your poison, it even helps with wife-friendly coilovers such as Bilstein and KW). With the typical set of low profile 18 or 19 inch tires, and at the typical lowered stance these cars look so good at, it turns the car from a bit erratic over bumps, to downright stable. The suspension is now more able to work in unison, left and right, front to back, whereas without the dampers, it’s a bit of a free-for-all, with the driver being asked to control it all on the fly. It is truly eye-opening how these simple bolt on devices stabilize the vehicle.

The neat thing about these, is they are available for several carswe get here in the US, including the Subaru WRX (02-07), 350Z/G35. Need one for your car? Just drop us a line!

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