Turbo upgrade guide for VW TDI and Audi TDI

back to 1000q: advanced performance upgrades

Introduction

A turbo upgrade for your TDI engine is an advanced performance upgrade due to cost, installation time, and because you need supporting mods to take full advantage of it.

Please see 1000q: basic performance upgrades for a list of easy and cheap performance upgrades to an modified car.  If you are looking at upgrades because you think your turbo is bad, please see 1000q: limp mode because power loss is often misdiagnosed as turbo failure.  If you have constant low power, see 1000q: constant low power or can't rev.  This list does not contain every possible turbo that will fit, 4 cylinder gasser VW turbos may fit but they will not work correctly.  Even though gassers may use a "k03" housing, there were many different turbos that used a k03 housing.  You may read k03, k04, etc, but there are actually a variety of turbos which use this housing name, many of which are not appropriate for the TDI.

This guide is organized 3rd generation/4th gen/5th gen VW and then by approximate maximum power that it can support.  These figures are provided by the vendors and myturbodiesel does not endorse any specific turbo because your car's setup should be tailored to your needs and exact car.  A listing here is not an endorsement of any specific vendor, this page is just a summary of what's available.  This site doesn't control what's on a third party's link and information provided by the linked vendors is not verified by this site as accurate.  Kermatdi, metalmanparts, and dieselgeek are active in the VW and TDI community.  Do some research before deciding which turbo or vendor to purchase from.  

Also note that although these tables have an "estimated maximum power" column, the power a turbo will actually make is limited by ambient atmospheric conditions, engine build variation, tuning, fuel quality, and supporting mods such as intake, larger fuel pump, injectors/nozzles, intercooler, and exhaust.  In other words, simply buying X turbo will not give you +50 hp.  You must have a chip to take advantage of the extra potential and supporting mods to allow an upgrade synergy.  Supporting mods by themselves give less power separately than when they are put together.  For example, x mod that adds 10 hp by itself and y mod that adds 10 hp by itself may give 25 hp when put on the same car.  Make sure to talk to your vendor about what supporting mods you need to reach the estimated maximum power that is advertised.

Some have est max supported psi instead of max power, psi is highly dependant on other factors so please note this figure is provided to only give a very rough idea of it's performance.  Remember that psi does not directly equal power!  Please see 1000q: turbocharging, common myths for more details.  You want to know the CFM, see the compressor maps, or talk to your vendor to confirm what turbo you want.  Lastly, estimated supported psi is sustained psi, and does not include spikes.  Large boost spikes for a gasoline car can cause severe damage, minor boost spikes on a diesel are normal.  A picture showing inducer/exducer and compressor (intake side) and turbine (exhaust side) is below.

For your sake, please buy a turbo from a reputable seller.  Buying cheap piping can work because it's a simple part but don't buy suspiciously low priced turbos because turbo failure can cause engine failure.  Piping is easy to make and fabricate but  turbos are precision machined parts.  There are vendors (not linked from here) who sell copycat and mismatched turbos.  One known seller of mismatched and bad turbos is This seller advertises bolt on turbos that are not direct bolt on and "k04 diesel turbos".  There was no k04 turbo used on a TDI and you can only use a k04 housing with a modified hybrid turbo.  Most of the parts this bad vendor sells appear to be copycat parts and are sold below the wholesale price of brand name parts, so buyer beware.  This seller also sells other poorly made copycat parts like TDI nozzles or rebuild kits.  I do not endorse or recommend any specific turbo, kit, or vendor, but due to many bad reports and one personal experience, I cannot recommend that business.

Building a flying TDI

A final note about turbo upgrades - it's fun to dream of building a car with all the highest power upgrades on it.  But it might not be the best car for you.  Consider your budget and your goal.  What other supporting mods will be needed to justify the larger turbo?  TDIs at higher power levels also need custom chip tuning, larger fuel pumps, other fueling mods, etc., and this all costs money.  Do you have the mechanical ability to do the work yourself or are you paying a mechanic?  Is there a TDI specialist near you who knows how to work on a TDI and not just a VW?  Do you want a daily driver that can go to the autocross track on weekends?  Then you should spend your money on sticky tires and suspension modifications.  You might not use the additional power every day but you do turn the wheel every day.  Maybe it would be better to spend money on suspension upgrades instead of power for your style of driving?  It's easy to look at this chart and get stars in your eyes but remember to keep realistic goals that suit your style of driving.  Don't put so much money into your car that you could have built a flying TDI instead!

Lastly, make sure the car is up to date with maintenance before doing any power mods.  There's no point in spending money on performance when the car might be damaged from lack of maintenance or won't see the full benefit of those mods.

Some of the turbos may be slightly different, include a install kit, performance package, or a core charge, so contact the vendor directly to see the differences.  If you have more questions about the turbo specifics, please contact the vendor directly.  If you are a vendor who would like to be included in this list, please make a request in the myturbodiesel forums. 

3rd gen mk3 TDI (1996-1997 Passat, 1997-1999 Jetta)

4th gen 1998-2003 New Beetle/Golf, 1999.5-2003 Jetta ALH engine

Note - some are direct bolt on, some are bolt on with adapters, and some use a separate manifold and installation kit.  You may also want to consider adding a cast exhaust manifold (fits all GT or T series VNT-20, 4 bolt flange, uses 4-2-1 design) (from JSperformance from Kermatdi from street toys) for some turbos which do not use an integrated exhaust manifold.  A welded exhaust manifold (fits fits GT or T series VNT-20, 4 bolt flange) from Kermatdi is also an option.

4th gen 2004-2006 New Beetle/Golf, 2004-2005 Jetta TDI BEW engine

Note - some are direct bolt on, some are bolt on with adapters, and some use a separate manifold and installation kit.  You may also want to consider adding a cast exhaust manifold ( fits all GT or T series VNT-20, 4 bolt flange, uses 4-2-1 design) from JSperformance from Kermatdi for some turbos which do not use an integrated exhaust manifold.  A welded exhaust manifold ( fits fits GT or T series VNT-20, 4 bolt flange) from Kermatdi is also an option.

4th gen Passat TDI 2004-2005, BHW engine

4th gen Touareg V10 TDI, BKW (2003-2005), BWF (2006-2007), and AYH or BLE (European) engines

There are no known turbo upgrades.  A turbo upgrade would require an engine pull and custom fabrication and tuning.  If you're not happy with the stock 310hp/553 lb ft of torque with a tow rating of over 7,700 lbs, want to trade?  Seriously though, any major turbo upgrade would probably damage the transmission.  The AYH and BLE European Touareg TDI engines 

5th/6th gen VW Touareg TDI and Audi Q7 TDI, CATA engine

The turbo used in the VW Touraeg 3.0L TDI engine and Audi Q7 TDI CATA engine is shown below.

5th gen Jetta TDI, BRM pumpe duse engine

Note - some are direct bolt on, some are bolt on with adapters, and some use a separate manifold and installation kit.  You may also want to consider adding a cast exhaust manifold ( fits all GT or T series VNT-20, 4 bolt flange, uses 4-2-1 design) from JSperformance from Kermatdi for some turbos which do not use an integrated exhaust manifold.  A welded exhaust manifold ( fits fits GT or T series VNT-20, 4 bolt flange) from Kermatdi is also an option.

5th and 6th gen Golf, Jetta, Audi A3 TDI with CJAA/CBEA 2.0L common rail engine

Other misc turbos and turbos for Euro engines

If you have any more questions on performance turbos, please ask in the Golf, Jetta, A3, and Passat TDI forum or search below.