Since its introduction, VAG's 1.8-liter turbocharged engine has been a favored powerplant for tuners and enthusiasts alike. It is revered for its technology, including five valves per cylinder and turbocharger system, which allows one to improve engine output without compromising driveability and, depending on the level of tuning, fuel efficiency and durability.
Neuspeed, a company with a long history of innovation and engineering excellence, has recently expanded its 1.8t tuning program to incorporate a new intercooler pipe, augmenting its P-Chip, P-Flo, stainless-steel exhaust, downpipe and turbo air intake pipe. While we generally try to work from a car that's completely stock, our test car, a 2001 GTI, had already been fitted with the turbo downpipe before the baseline numbers were gathered. Because it's welded to the catalytic converter, we saved time at the expense of a slight skewing of the procedure's final results.
With the number of parts involved, many owners might prefer to build up their cars one part at a time or in groups of parts as time allows. Aaron Neumann, chief tech guru of the Neuspeed clan, suggested the best bang for the first bucks is the chip. In its most aggressive state of tune and with race gas, it can yield up to 30 hp. One item of note: The 2001 1.8t engines (Golf, Jetta and New Beetle) and newer use a hybrid turbo that's essentially a K03 on the turbine side and a K04 on the compressor side. This is one of the ways the newer engines make more horsepower.
Neuspeed downpipe (bottom)...
Neuspeed downpipe (bottom) vs. stock
As I looked on, Aaron built up a project car step-by-step. If you're doing the work at home, remember the safety basics we've said time and time again about level concrete surface, jack stands, Bentley manual for backup, guts, burns, safety glasses, leave the job to a professional if you're unsure, etc. Also, visit european car's Web site at www.europeancarweb.com for more in-depth photos of Aaron's long day of work.
Neuspeed intercooler (bottom)...
Neuspeed intercooler (bottom) vs. stock
ECU
Due to its electronically controlled boost, the 1.8t responds very well to chip tuning. In the old days, turbo boost was literally controlled by cranking down the spring on the wastegate and hoping for the best. A modern Bosch Motronic ECU, such as that on the 1.8t, controls the engine based on a seemingly endless number of sensor inputs. In designing its P-Chip, Neuspeed altered the fuel, boost and timing curves for improved engine performance. When using any chip, it's generally a good idea to use the best gasoline possible. With the knock-sensing ignition, a lame tank isn't going to cause the engine to grenade, but performance will suffer.
Neuspeed turbo intake pipe...
Neuspeed turbo intake pipe (top) vs. stock
Removing the ECU from a Golf or Jetta IV is a straightforward procedure, requiring the removal of the plastic trim under the windshield wipers, and the wipers themselves. For the New Beetle, it's even easier; the ECU is under the cover in the middle of the dash.
Because the chips are soldered to the board, replacing it with a modified chip can't be done at home. Send your box out on Monday, Neuspeed receives it on Tuesday and performs the swap and it's back in your hands the next day.
Go With The Flow
A chip is the first thing you want to do when building your car, but it works best when combined with a free-breathing engine. For that reason, Neuspeed has a number of bolt-on parts that address engine flow from air filter to tailpipe tips.
The program begins with the removal of the stock air filter box and replacing it with Neuspeed's P-Flo. For those who don't know, P-Flo is a special filter element that bolts onto the stock MAF sensor. Installing a P-Flo takes all of 10 minutes (see www.europeancarweb.com for photos showing the procedure).
For further down the airstream from the P-Flo, Neuspeed developed a turbo air intake pipe that's larger and less restrictive. In producing its turbo pipe, Neuspeed uses a casting process, just like the factory part. Replacing the turbo air intake pipe is best done when installing a P-Flow, mostly because the air box will be out of the way.
On the compressor side of the turbo, air being introduced into the engine is channeled through an air-to-air intercooler. If you turn your wheel to the right, you can see a flat, crimped pipe on the front inside edge of the wheelwell. Neuspeed's replacement turns the flat section of pipe into a round tube, which logic would indicate leads to more efficient flow. One nut and two clamps/hoses have to be removed in order to swap out the pipes; it's another 10-minute job.
On the other side of the airflow equation is the turbine side of the turbocharger. The spent exhaust gases that drive the turbo exit via a cast-iron manifold--to which the turbo is bolted--then pass through a downpipe on their way down to the catalytic converter. There are a couple different downpipes used on different model years of cars, but from the picture you can see how the all-stainless Neuspeed part is larger and offers a more direct path.
Replacing the downpipe requires welding and shouldn't be attempted by the average home enthusiast unless you're handy with a TIG welder.
On the aft side of the catalytic converter is the exhaust, hence the cat-back nomenclature. Removing the exhaust is a simple procedure and can be done at home. The first step is to cut the exhaust into two pieces. If you follow the pipe back, you will see a spot where the pipe turns 45 degrees, and in the straight section between the next 45-degree turn there will be a spot with three punched marks on the pipe. Cut the exhaust at the middle dot. If you were replacing the exhaust with factory pieces, particularly one-half of it, you would cut on that dot and the other half would fit properly. When the cars are made, it's welded and installed as one piece.
After cutting the exhaust pipe, unfasten the center piece from the catalytic converter and remove all the nuts holding the boomerang-shaped support from underneath the car. If the car on which you're working has a factory exhaust and a lowered suspension, you may have to remove the lower left-rear shock bolt and have a friend yank down on the left rear wheel/tire in order to sneak the exhaust over the rear axle beam. When installing the Neuspeed exhaust, you may have to replace the factory rubber mounts if they're cracked.
With all of the parts on the GTI, we went back to the dyno for a couple more pulls. Beforehand, the GTI turned 132 hp at 6200 rpm and 136 lb-ft of torque at the road at 2850 rpm. In modified state, the same car on the same dyno on the same day delivered a peak wheel hp of 179 at 6000 rpm (224 at the engine). For torque, the improved breathing and boost helped deliver 207 lb-ft at the road (258 lb-ft at the engine) at 3400 rpm. This equates to a 35% increase in peak road horsepower and a 50% increase in peak road torque.
The gains displayed are what one would expect from a well engineered and integrated package, and it's testament to Neuspeed's heritage of excellence.
Neuspeed
3300 Corte Malpaso
Camarillo, CA 93012
(805) 388-7171
www.neuspeed.com