(Editor's note: Special thanks to Raffi Kazanjian at EuroSport for help with the installation and removal of 13 exhausts.)
We often receive letters from readers asking, "Which widget or framus is the best for me and my car?" Usually these are dropped in the file of letters headed, "Wants product name rec.," with the sub-heading, "To be ignored." The reason is simple: While we can investigate products and report our findings about quality and performance, to simply say, "This product is THE BEST," opens up a whole ration of problems. Magazines have been sued successfully for saying that. How do we know it's the best? Have we objectively tested every competing product? In general, we haven't, which makes it impossible to say one is better than all the rest.
We got tired of that, and decided to do something about it. We can't do every part, but exhausts are a popular item, so we started with them. It was a lot of work, but we chose a popular car, the Jetta 1.8T, and invited every exhaust manufacturer we could find to send us its product. Thirteen responded by sending their products for us to test. We inspected them, photographed them, installed them, drove them, and put them on the Dynojet 248C at the McMullen Argus Tech Center. This article is the result.
Putting exhausts on a 150-bhp stock car wouldn't really reflect what readers will be doing with them, however, and wouldn't really show the differences in performance. To truly test the exhausts, we needed more flow. We installed a Neuspeed P-Flo(TM) intake and 1.8T High-Flow Turbo Intake Pipe, along with a GIAC chip. Most readers will be familiar with Neuspeed's line of intakes. The 1.8T High-Flow Turbo Intake Pipe fits all VW Golf IV, Jetta IV and Beetle 1.8T cars, plus Audi TT models equipped with the 180-bhp engine. It bolts directly to the turbocharger and uses factory mounting hardware for a perfect fit. Neuspeed states it moves 70-percent more air than the factory air inlet pipe, and gains an extra 7 bhp on an otherwise stock engine. We believe it was the basis for significantly greater gains when the boost was turned up. By smoothing airflow into the compressor, it allowed the tiny, stock KO3 turbo to deliver the air needed to make significantly more power than is generally considered possible without upgrades. It seems to be a case of Neuspeed having looked at a detail others ignored and finding another way to make big improvements. Together with the GIAC chip, these changes increased the Jetta's peak output from 143 hp at 5700 rpm at the wheels to 180 hp at 4970 rpm with the stock exhaust.
Opinions vary on the driveability of this configuration. Les Bidrawn is in love with the sheer grunt the car has. Indeed, with four people in it on the way to lunch, three of them were asking what was in this car to make it pull so hard. At the dry lake for another photo shoot, the Jetta had no problem finding its speed limiter. On the other hand, part-throttle response around town was less than smooth at times. While boost was increased, the coefficients used to control response didn't seem to have been dialed in correspondingly, and several drivers wanted to send it back for further development.
A further consideration is that stock Jetta suspension, brakes, and tires are barely adequate for performance driving with 150 bhp on tap. With flywheel horsepower well above 200, as it was in this test, the car was rather unbalanced. Before achieving engine output on par with what you will see here, we strongly suggest some careful and thorough upgrades to the aforementioned areas.
As with engine software, there is far more to the equation than simply how much power is developed. How loud is the exhaust? Are there booming resonances? An exhaust that makes the hair on the back of your neck stand up and puts a big, stupid grin on your face at wide-open throttle and 6500 rpm can also feel as if it is going to liquefy the contents of your skull at a steady 2700-rpm cruise. If it does that, you will hate it. The quality of an exhaust includes its construction: How clean and smooth are the welds? What materials are used? What is the finish? An exhaust must be installed. Does it fit or does it rub a suspension component and rattle? Are the hangers aligned well? Is the hardware quality or is it cheesy? We included all these questions in our evaluation.
Exhaust Evaluations for 1.8t Jetta
Cut the exhaust between these...
Cut the exhaust between these two dimples for resonator-back systems.
Note the difference between...
Note the difference between the turbo inlet pipes. ABD's chromed unit on the left is beautiful...too bad it doesn't show. The Neuspeed system we used features the same finish as the factory piece on the left. It's very nice.