Skyline Style: The B15 Sentra SE-R

Monster Meats and Torque

That 2002 Sentra SE-R followed a path blazed a decade earlier: more power and more stick. The Disco Potato’s turbocharged engine didn’t make it into production, but the car did get more grunt. Thanks to similarities with the maker’s larger cars, the SE-R received a 2.5-liter four-cylinder from the Altima. 

This new QR25DE engine made plenty of power, even if it didn’t like to rev to the stratosphere. In SE-R tune, it was rated at 165 horsepower. The 180 lb.-ft. of torque made up for some of the loss of revvability and helped make the heavy cars feel faster than they were.

The real star of the show was the SE-R Spec V. In place of the SE-R’s five-speed manual or four-speed automatic transmission was a six-speed transaxle fitted with a helical limited-slip differential. Performance rubber on 17-inch alloys replaced 16-inch wheels. Horsepower went up to 175.

Suspension tuning was firmer than on the SE-R, too, with more aggressive rear roll stiffness. Larger front brakes round out the major mechanical differences. As before, Nissan offered a lot of performance for the price. For around $17,000, buyers could drive off the lot with a new Spec V.

Inside, the Spec V had unique red and black upholstery on a more aggressive seat design. Both versions received the same distinctive exterior bits: blacked-out headlight trim, a rear spoiler and an aggressive front bumper. 

Half-Baked Potatoes

Reviews of the new SE-R and Spec V were mixed. Most testers loved its engine’s torque and the grip offered by the helical limited-slip differential. Big tires and stiffer suspension gave the car impressive road holding: A few testers measured peak lateral acceleration around the .85g mark. 

Its seats were noted as comfortable and supportive, but that’s about where the praise stopped. The Spec V was given very short gearing to make the most of the QR engine’s torque, and the buff books frequently faulted this since the car required third gear to reach 60 mph. 

The second issue was the car’s inconsistent real-world performance. While it felt fast, timed data revealed an engine that didn’t always deliver the same performance run after run. 

Other nitpicking revolved around the overall fit and finish of the interior. It didn’t seem as nice as the rest of the field, but remember: The SE-R was priced below its competition. 

Unfortunately, after the launch a few more issues started to surface. One was a tendency for the engine to consume excessive oil. A few engines even failed catastrophically. Numerous TSBs tried to head off the problem; Nissan developed several software updates for the ECU in an attempt to address the root issue. Many early QR25 engines were replaced under warranty. 

The cause? Bits of catalyst got sucked into the engine during overlap. 

Another issue took a few more engines out of service: The tiny screws that secured the secondary throttle valves would occasionally vibrate loose and go into the combustion chamber.

These problems are less common today. Upgrades eliminated those issues for 2003, and many 2002 engines were replaced under warranty long ago. Transmission gearing was revised for 2003 so the Spec V could reach 60 mph in second gear.

The B15-chassis SE-R continued through the 2006 model year, and while they may not enjoy the cult status of the original, these cars now make comfortable, practical daily drivers and track toys.

Things to Know

The B15-chassis Nissan Sentra SE-R and Spec V make fun, inexpensive daily drivers. Since we like to row our own gears, we’d have to go with a Spec V model or an early SE-R.

Engine and Drivetrain

“We’ve found that the stock motors, even from 2002 to 2003, last for a long time if you change the oil often,” says Joe Ippolito of B15 Sentra specialists 2J Racing.

“For a street car, the catalytic converter is the one weak point because it’s known to break up and destroy the engine,” says Kyle Millen of longtime Nissan tuning house Stillen Motorsports. “Other than that, some heads have trouble since the combustion chamber has a thin wall and tends to crack around the top.”

Removing the upper plenum and adding a drop of threadlocker to all of the secondary runner butterfly screws is a prudent, 30-minute project, says Ippolito.

“The 2004-and-up ECU runs on a CAN bus system and can be tuned via Uprev tuning software,” Ippolito explains. “The 2006 is the best because it has a factory wideband O2 sensor and can make air/fuel ratios almost perfect, even with a turbocharger.” The 2004-and-up cars also use a much more reliable MAF sensor, he adds. 

The 2004 gear ratios are the best of the three variants for performance, Ippolito says. 

Both Millen and Ippolito recommend an exhaust header. Figure it’s worth 7 to 12 horsepower, but Ippolito warns that not all are created equal. 

Enthusiasts often remove the balance shafts with a Jim Wolf Technology kit. This move adds a quart of oil capacity and, according to Ippolito, frees up some horsepower. Removing the shafts does introduce some annoying harmonic resonances, however.

Kyle Millen recommends the JWT cam set: “We were very surprised when we saw 200 horsepower at the wheels with the cam set, new valve springs and a 7700 rpm redline thanks to the QR-Pro.”

The QR25 engine does take to turbocharging, but consider stronger aftermarket pistons and rods. “Anything over 350 horsepower breaks [the stock] rods,” Ippolito adds. 

A V6-powered SE-R? Yes, it’s possible, and 2J Racing can make that swap a reality. The 2002-’06 Nissan Maxima VQ35 is almost a direct bolt-in. The weight gain is about 37 pounds.

Body and Interior

The B15 holds up well to abuse, but don’t be surprised by worn leather on the steering wheel, scratched dash plastic, and snagged seat upholstery. 

The Lava interior looks cool—well, to us, anyway—but the fabric stains easily. 

Suspension and Brakes

Kyle Millen recommends combining Eibach springs with Koni shocks. It’s what he runs on his street car. 

The rear twist beam has a very high roll center, and 2J has found that replacing the Scott Russell link with their Panhard rod can make the front and rear roll centers work better together.

The factory rear alignment often has a ridiculous amount of toe-in—some cars have as much as 1/4 inch built into the beam. A good alignment shop can tweak the beam to give neutral toe, which makes for a more predictable transition to oversteer.