Pat Dolan said:
I wouldn't discount the 2.5 I-5 as anything but the very best of VWs technology. If you watch Kleinschmidt or whoever in a PDK Touareg, you are watching the 5 cyl, NOT the V-10 TDI. In other words, VW Motorsport is one source for 2.5 tuning info, and I should imagine the chip tuners know the engine as well.
Karl: Please don't refer to the VW engines as common rail, since they are anything but. The current PD engines are unit injectors (an evolutionary dead end since they cannot accomodate dissolved/released air in the fuel). The new Audis are indeed CRTDIs - which means that the fuel pressure is boosted to delivery pressure in the "common rail" and the injectors (peizzo-electric ones) are on-off valves (with incredibly fast response times in this case).
Thanks Pat for the perspective, but I know what PD’s are and why VW/Bosch are dropping them. I learned about piezo-electric injectors in my VW Driver and Audi Driver Magazines before this development was mentioned here in the TDi Club forum.
As I said I use the term “common rail” as short hand for this reason. Outside this forum, outside the USA for that matter, the most common term associated direct injection diesel engine technology, regardless of what fuel system is actually used, is “common rail.”
Quick! How many tdi engines have been using common rail over the last ten years and who makes them. Well, I do not know off the top of my head, but if I check every issue of the British magazine CAR I have (I still have almost every issue since I saw my first copy in 1983.) I am sure I will most likely find more brands of tdi diesels fitted with common rail than not, given the development of tdi technology outside the VW/Audi Group. (Otherwise I have been reading wrong all these years and I never claim to be perfect.)
If I said, “Super 90” what is the first thought that comes in your head? I would hazard to say if you have heard the term before, it is in association with Porsche.
Correct?
Or did you say Audi.
Most people, who would know, would say Porsche and would be correct. I have found few who know, even at Audi Dealers, that the first Audi ever sold in the USA was called a “Super 90.” It was a “Super 90” because it required Premium gasoline (95 –98 RON) and produced 90 hp DIN. And to describe the Super 90 fully, I would have to explain the basis of the Super 90 and how it fit into a model lineup that was all the same except the models were delineated by the engine horsepower, not engine displacement (but was related) and trim levels. Yet, in point of fact, it is even more detailed than that.
My point here is that, as I stated originally, I use term “common rail” as short hand, so that every discussion, especially outside this forum, is not a full blown technical dissertation when the basics of TDi Technology are that Direct Injection Diesels require [ever] higher fuel system pressures with more precise and adjustable injection times in a drive to produce greater power and torque over a specific RPM range with ever increasing regard to fuel consumption and emissions in which “common rail” fuel systems are the systems of choice for these on going developments in passenger cars. This was true very early on in the growth of TDi technology, especially outside of the VW /Audi Group.
As for performance tuning of either a first or second-generation Audi 2.5 L 5-cylinder diesel let me address the first generation motor, first.
As this motor was converted to direct injection rather late in its production life, I do not doubt that there is little, if any, performance tuning available for this motor, nor do I ever recall there ever being any.
In the heyday of the 2.2/2.3 L 5-cylinder gasoline motor very little was offered in the area of engine tuning, be it a 20V or 10V Turbo, or normally aspirated motor. In 1991, at the Frankfurt Auto Show the premier VW / Audi tuner, Abt, offered no engine enhancements, of any type, outside of a post catalyst exhaust for the then current production type 89 80/90 model Audis, for example.
With respect to the 2.5 L R5 5-cylinder motor running in VW Motorsport supported Touaregs. If past patterns follow, with VW and Audi racing cars over the past 31 years, very little of the motor, outside of the short block, will resemble a production [second generation] 2.5L R5 5-cylinder.
Of the two preeminent VW/Audi tuners, Abt Sportline and M-T-M (Motoren-Technik-Mayer), only Abt offers performance modifications for the 2.5L R5 5-cylinder in the form of “chip tuning” (128 @ 3500 rpm to 152 @ 3800 DIN). M-T-M’s sole focus is on the V-10 TDi.
I drove a few of the original Audi 5-cylinder diesels sold in the USA when they were current models [and I serviced VW's and Audis for a living] and I loved them. I very much enjoyed the gasoline versions, especially in the type 85 and type 89 quattro’s I’ve owned too.
But I must say I still believe, given all our discussions so far, that the conversion of 1.9 TDi to either a 2.5 V6 TDi or 2.5 R5 TDi is not the best option given the tuning developments that already exists for VW/Audi models of A4/A6 already equipped with either the 1.9 or 2.5 TDi’s from the factory.