Like most car enthusiasts, TDI drivers are always looking for various performance upgrades for their diesels. If you’re looking for ways to enhance the driving experience of your Mk4 or Mk5 Volkswagen TDI, you’ve come to the right place! In this guide, we’ll explore some of the most popular and effective modifications that can significantly improve your TDI’s performance and fuel economy.
Turbocharger
One of the most popular modifications is an upgraded turbocharger. With higher flow, larger compression wheels, and upgraded actuators, these turbos will give your vehicle more power.
VNT-17
The VNT-17 which is available for both ALH and BEW is a significant upgrade over the stock turbos found in these vehicles. The ALH had a VNT-15 as the stock turbo while the BEW engine used a KP39 turbo. This upgraded turbocharger will give your vehicle higher boost levels and many believe superior durability. Installing this turbo is fairly simple. The only major difference between it and a VNT-15 is the compressor (cold side) exit. The VNT-17 has a clip fitting that requires a VW hose or an adapter.
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PD140
The PD140 is an upgraded turbo from Garrett for BRM engines. It comes from the 140 HP 8 valve TDI (engine code BMM, 140 HP) in Europe. This turbo is a good mild upgrade from the Borg-Warner stock turbo. It can easily run 24 PSI and boost is less likely to creep when running more fuel.
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Boost Gauges
Now that you’ve upgraded the turbo in your vehicle, you’ll need a way to monitor the vitals of your engine, including oil pressure, EGT temperature, and boost levels. Many failures that involve upgraded turbos are due to overboosting. We offer a variety of products that can be installed in your car to keep an eye on these levels to ensure you don’t overboost and damage that new turbo.
Fueling Upgrades
There are several different options available to upgrade your vehicle’s fueling system:
Injector Nozzles
There are several OE and upgraded OE nozzles available from Bosio, a leading brand of nozzles.
Here are some basics on stock nozzle sizes:
- .184 Bosch nozzles were standard on early VE TDIs. Bosio uses the number 706 (preceded by DSLA 150P)
- .170 Bosch nozzles were on later VE TDIs with manual transmissions. However, the most common replacement for these nozzles is the .184 size, same as in the earlier cars. The difference in fueling is nominal.
- .158 Bosch nozzles were used in ‘99.5 – ’03 automatic transmission TDIs. Bosio uses DSLA 150P 442 as its number
Then there are upgraded nozzles. Here’s a chart converting Bosch nozzle sizes to Bosio number.
Upgraded Injectors
In addition to injectors, another option is to get injectors professionally rebuilt and calibrated with upgraded Bosio nozzles by Bosch professionals.
Remember that the best build for your Mk4 or Mk5 begins with a plan. If your goal is more power and you decide to upgrade your turbocharger, then other components might need to be upgraded to aid in handling increased power. If you’re looking for inspiration or information on upgrades like these, consider searching online forums to see if someone has documented the upgrade you have in mind. Diesel on!
