Being an engineer and into details, one of my favorite sayings is "Speed doesn't kill, rapid deceleration does!" Rapid, as in "nearly instantaneous deceleration caused by hitting hard immovable objects."
To avoid such traumatic episodes, it's important to have good brakes. So far in Project SE-R, we've pumped the engine to develop nearly three times the stock power and have installed a suspension worthy of a racecar with big sticky tires to carve corners.
To date, we have neglected the braking system. The benefits of exotic car cornering and power can negated with econo-car brakes. To restore balance in our car's performance envelope, we will concentrate on bringing the car to a stop.
Big BrakesThe stock Sentra SE-R's brakes, although good on a stocker, suck for extreme use. The standard Sentra brake rotor is a mere 18mm thick and a wimpy 9.8 inches in diameter.
We borrowed some technology from real racecars and replaced these anemic stoppers with Fastbrake's brake upgrade kit. Fastbrakes is a well-known name to the Honda enthusiast, making inexpensive, but fast-stopping, brake kits for all popular Honda applications. With some nagging and cajoling, we convinced Fastbrakes to develop applications for most popular Nissans.
The Fastbrake kit uses Wilwood's four-piston Dynalite calipers, replacing the stock Nissan floating one-piston calipers. The Dynalites feature a small 1.38-inch set of pistons, so a reasonably sized master cylinder can be used to keep a firm pedal.
The Dynalites are CNC machined from billet 6061 aluminum for stiffness and to minimize weight. The calipers are fitted to the SE-R's stock unmodified spindles with CNC-machined 6061 billet adaptor brackets and the provided hardware.
One advantage to using a popular racing caliper is the huge assortment of racing brake pad applications available for them for a much lower price than racing pads made for stock calipers. This can offset the purchase price of the calipers after just a few track events.
We opted for Hawk's ferro -carbon HPS pads which, in our experience, have worked well over a wide temperature range while not being very dusty, a nice feature if you like to keep your rims clean.
The Fastbrakes kit contains an 11.5-inch diameter and 20.5-mm thick iron Wilwood racing rotor, bolted to an attractive blue anodized 6061 aluminum hat. The aluminum hat keeps heat out of the wheel bearings and reduces unsprung and rotating weight. These huge brakes are 1.7 inches bigger than the stock rotors and, despite the size difference, are 5 pounds lighter due to the alloy hat and caliper.
The bigger rotor provides a large gain in the rotor's swept area so the rotor itself will run much cooler. Also, the bigger diameter gives the caliper a much bigger moment arm to provide decellerative force. This gives the brake more powerful feel with more stopping abilities and less pedal effort.
With these bigger brakes, a 15-inch or larger wheel must be fitted for clearance. Fastbrakes sells the rotors in drilled, slotted or plain configuration. We opted for drilled because it's the hottest looking combo.
Drilled brake rotors can crack easier. But since we know these big brakes won't run as hot as the smaller stock rotors, we decided to take advantage of the holes to vent the pad's hot boundary layer gases.
To keep our bigger brake system in balance, we also upgraded the rear brakes. We used Fastbrakes' big rear rotor. The Fastbrakes rotor is a large 10.2 inches in diameter and 9mm thick vs. the stock 9.2-inch diameter and 7mm thickness.
Again, we opted for a drilled rotor to match our drilled front rotor. Calling our friends at Courtesy Nissan for genuine Nissan parts, we used a caliper from a 1992 to 1994 Maxima SE to complete our big brake conversion. This caliper uses a much larger brake pad and accommodates the larger rotor, while bolting directly to the SE-R's rear spindle.
The brake lines and parking brake cables bolt on the big Maxima caliper, a set-up that provides nearly the same rear brakes as the much larger, heavier Maxima on our tiny Sentra.
To firm the pedal, the Fastbrakes kit also included some Teflon-lined braided steel brake lines. These lines resist swelling, which gives a firmer feel to the brake pedal. To make our brake pedal even firmer for better modulation, we used a 1994 Altima master cylinder from Courtesy Nissan as that has a bigger piston bore (15/16 inch vs. 7/8 inch). The bigger bore displaces more fluid given an equal stroke to give the brakes better feel with a shorter pedal stroke.
We bled the brakes using Motul's new RBF 600 brake fluid. RBF supercedes Motul 600 as Motul's top-of-the-line brake fluid. RBF has a higher wet and dry boiling point than any brake fluid currently marketed.
While racing, I've yet to experience any fluid-based fade on any racecar using RBF. RBF's high wet boiling temperature also makes it an exceptional high-performance street brake fluid.
The big brakes are totally awesome. The brakes are powerful and easy to modulate. The brake bias is good, with the front brakes locking slightly before the rears. Triple digit stops and hard laps on a road course have yet to induce any fade, which is much more than could be said of the stock brake attempting to counter turbocharged thrust.
The big brakes look really awesome. The tiny stock brakes looked ludicrous behind our big 17-inch wheels. The stock rear brakes looked especially ridiculous.
With the brakes, Project SE-R is getting pretty extravagant. A tiny econo box with exotic-killing performance is an entertaining sleeper. No one expects a Sentra to be fast or nimble, especially the owners of muscle cars and expensive sports cars.
Stay tuned. In the coming months we'll go inside the engine to build a turbo-specific engine, add some refinements to the turbo system for more power and do some work on the anemic Nissan gearbox to strengthen it for reliability and additional power-handling capability. We plan on taking Project SE-R further than any Sentra has ever gone.
Fastbrakes' big brake kit is complete, with everything you need for a clean install.
The huge size difference between stock and Fastbrakes is apparent when the parts are laid side by side.
An Altima master cylinder, with its larger piston, was used to shorten the pedal stroke and provide a firmer pedal feel.
The front brake, when bolted in place, looks like it belongs on a racecar-quite an upgrade from the typical drilled stock size rotor.