Turbo types on Golf V

[CatonaPC©]

Not sure is this question has been answered, so here goes.

What are the differences between the various TDI turbos available in the 77KW, 103KW and 125KW TDIs?

[Maverick]

Doesn't work that way in the world of engines (at least not for VAG cars). There are quite a few changes and these were detailed in a thread early last year on here or golfmkv.com. Turbo is different along with quite a number of changes inside the engine.

[Greg Roles]

To answer the question, I know the 103kw has a garrett vnt15 and the 125kw a vnt17, bigger turbo, both variable vane. The 125kw has a more precise vane controlling mechanism.

I just read on TDI club the 77kw 1.9L has the Vnt15 as well.

[CatonaPC©]

Doesn't work that way in the world of engines (at least not for VAG cars). There are quite a few changes and these were detailed in a thread early last year on here or golfmkv.com. Turbo is different along with quite a number of changes inside the engine.

Any chance of a link?

To answer the question, I know the 103kw has a garrett vnt15 and the 125kw a vnt17, bigger turbo, both variable vane. The 125kw has a more precise vane controlling mechanism.

I just read on TDI club the 77kw 1.9L has the Vnt15 as well.

Which TDI Club?

Thanks for the info on the vnt15, as I was wondering if mine had variable vane or a wastegate. Still like to find out more about what is actually in my car.

[Maverick]

Any chance of a link?

Can't find a link but I did save this from when I had a tractor on order last year.

------------------------------------------

Here is the difference between the 2 TDI engines - the outputs vary within each of the specifcations depending on ECU. The new 2.0 TDI as far as I know, does not have a Variable Geometry Turbo (VGT). This engine is being phased out over the next few years, in favour of an all new design, with the Pump-Dusse injection system being replaced with a Common Rail injections system.

2.0 TDI with 103 kW: 209 kph is the top speed of the 103 kW / 140 bhp (at 4,000 rpm) Passat 2.0 TDI. The four-cylinder engine develops a maximum torque of 320 Newton metres as low as 1,800 rpm, and takes just 9.8 seconds for an easy 0-100 kph sprint before reaching the top speed of 209 kph. Average consumption: 5.9 litres. This TDI performance level can be combined with a diesel particle filter.

Numerous details were modified in order to facilitate the use of an optional, additive-free diesel particle filter in the 2.0 TDI. Some examples: in order to allow the DPF to be mounted as close to the engine as possible, the position of the exhaust turbocharger was changed. The pressure with which the pump-jet element injects fuel into the slightly modified combustion chambers was also increased to as much as 2,400 bar. In addition to this, the pumping characteristic of the pump-jet was modified to allow additional injections for the thermal regeneration of the filter or other reasons. Engineers concurrently succeeded in further reducing the oil consumption, another measure to increase the efficiency of the DPF. The diesel particle filter is maintenance-free, and forms a modular unit with the oxidation catalytic converter.

2.0 TDI with 125 kW: The second 2.0 TDI, fitted with highly innovative piezo pump-jet high pressure injection and a compensator shaft, is a completely new design. This very quiet, four-valve TDI has an output of 125 kW / 170 bhp (4,200 rpm), develops a torque of 350 Newton metres (1,800-2,500 rpm), and accelerates the saloon to 100 kph in just 8.7 seconds. The top speed is 223 kph. Here, too, the average fuel consumption is low, at 6.1 litres over 100 kilometres.

Technically, the 125-kW TDI, with its switched induction manifold for turbulence control, is based on its 103-kW equivalent without diesel particle filter. This cultivated engine is the world's first piezo pump-jet TDI. Further technical features are two compensator shafts (reducing secondary vibrations by up to 80 percent), a maintenance*free diesel particle filter, and an injection pressure of up to 2,200 bar. The specific power of the 2.0 TDI, at 62.5 kW per litre, is a new best. Although the new TDI has power and convenience characteristics that come very close to those of a five- or six*cylinder turbo-diesel, the consumption and emission figures are in the low four-cylinder range.

Technologically, a central factor in the achievement of high power and convenience values together with low consumption is the use of the newly developed piezo pump-jet elements. Using one of the piezo actuators to control the high-pressure valve of the pump-jet permits:

· -very high injection pressure, and thus low emission and optimum specific power.

· -ideal hydraulic efficiency because of the very small high*pressure volume.

· -ideal injection process.

· -very precise, low-volume pre-injection at a low pressure level.

· -flexibly controlled pre- and post-injection and injection intervals.

· -low injection noise.

A further innovation in the TDI is the use of a newly developed compensator-shaft module. The term "module" is easy to explain: the two counter-rotating compensator shafts (turning at twice the engine revs), together with the oil pump, form a separate module located under the cylinder crankcase. The compensator shafts noticeably reduce the amount of vibration that is transmitted to the bodywork.

---------------------------------------------

Golf GT TDI / 125 kW: As the strongest TDI power train of the series Golf, Touran and Passat, Volkswagen offers a completely newly developed 2.0 TDI with 125 kW / 170 PS (at 4,200 rpm). This four-valve TDI with piezo elements and standard diesel particle filter develops a maximum torque of 350 newton meters between 1,750 and 2,500 rpm. The strongest turbo diesel ever used in a Golf accelerates the best selling car in Europe in only 8,2 seconds to 100 km/h. The Golf GT TDI reaches its maximum speed at 220 km/h. The average consumption is extremely low: according to the norm 99/100/EG, 5.9 liters are a peak value for such an agile car. This GT is shifted via a manual six-gear transmission. Just like for the Golf GT TSI, the automatic double-clutch transmission DSG will be available optionally starting this summer.

[CatonaPC©]

Thanks. This generates more questions. On the one hand it says the 103kw and 125kw differ in power because of the ECU. Then it goes on to spell out details of the 125kw TDI, including balance shafts.

I only thought differences were limited to turbo size and ECU, as many in this forum simply flash their ECU to get more power out of the 103kw.

The writer also isn't sure if the turbo isn't a variable vane type.

[Maverick]

Thanks. This generates more questions. On the one hand it says the 103kw and 125kw differ in power because of the ECU. Then it goes on to spell out details of the 125kw TDI, including balance shafts.

I only thought differences were limited to turbo size and ECU, as many in this forum simply flash their ECU to get more power out of the 103kw.

The writer also isn't sure if the turbo isn't a variable vane type.

I'll try and find the one I was thinking off tonight which goes into more detail, there were quite a few changes including the balance shafts between the two. But one of the drawcards of the 125kw TDI is also one of the drawbacks and that's the DPF, whilst it stops the puff of smoke under hard acceleration it also restricts flow and limits the gains from flashing.

[Greg Roles]

Both 103 and 125 ARE variable vane. The balancer shafts are only in the luxury cars, such as the Passat. The changes I've listed before, from the VW self study program on both engines from Erwin.

I can't find my old definitive post, but from memory-

Forged and lightened crank
Extra water cooling around injectors and head
Higher injection pressure / diff injectors
dreaded DPF
Higher compression
More advanced EGR cooler
VNT travel feedback - more sensitive control
different pistons
bigger turbo


that's about all I can remember!