Audi A4 BTCC / STW engine specs - 305 bhp from an N/A valver.

Awesome. So working on a project presently that will make 300hp from just over 1700cc at 11K rpm on regular Vpower petrol. Amazing how all this moves on but is still a bit the same - none is new tech especially. Friction reduction is very important....

 

Audi's engine guru retires: Ulrich Baretzky on 3 decades of ingenuity

LE MANS NEWS
MAY 21ST 2020

Ulrich Baretzky's innovations with direct injection and diesel engines helped power Audi to 13 Le Mans victories. Ahead of his retirement in June, he looks back on his triumphant career


Audi
AUTHOR
Lawrence Butcher

From 1999 to 2016, Audi was a dominant force in sports car racing, and before that saw great success in Trans-Am and DTM. Behind these efforts, supplying many of the company’s engineering firsts, was Ulrich Baretzky, head of Audi Sport’s engine department, who retires next month.
Despite lockdowns across Europe, he is still working flat out, but took time out to look back at his diverse career of innovation with the Ingolstadt marque.
Houses not cars

Ulrich Baretzky never set out to be a motorsport engineer. In fact, in the early ’80s, he was training to be an architect. “I was never interested in engines or motorsport,” he says. However, a realisation dawned that he would end up designing buildings he didn’t like and this, by turn of fate, led him to BMW Motorsport.
“I went in the mechanical engineering direction with my studies and a friend [who worked for BMW Motorsport] said they were looking for a designer. One of my university projects was designing and doing the calculations for an engine, it was a horrible engine – based on the Rover 3500 inline six. My friend told me to bring the design work to the BMW interview.”
At the time, Paul Rosche was head of BMW Motorsport, “he looked at my project and said, ‘when can you start?’” Initial impressions were promising, “when I arrived, it was Rosche’s birthday, so we immediately left the office and returned eight hours later drunk. I thought if it continues like this, I will be an alcoholic, but not a designer.”
Real work commenced in short order and his first project was working on the then all-new M5 engine. After almost a year developing the road car powertrain, he moved to BMW’s Formula 2 engine program, and then, in January ’83, was placed on the Formula 1 project. “I was the second designer, of two, can you imagine that these days? I was responsible for the turbocharger and intake, it was a very complex system – mechanical, not electrical – but quite old fashioned. It was a successful year and BMW became world champions.” Recalling the post championship revelling, he says. “That year was the first and only time in my professional career when we really celebrated a victory, for three days continuously!”



Baretzky the project leader for novel engine position in the Brabham BT55
Grand Prix Photo

He went on to work as project leader on the then revolutionary engine installation for the Brabham BT55, which canted the motor over to improve flow to the rear wing. However, Baretzky and Rosche’s personalities would often clash, sowing the seeds for his move to Audi. “I was not really happy at BMW and I had conflict with my [immediate] boss and Paul Rosche. I have to say, we didn’t get on very well because, I think, we were too similar. Both Bavarians, both very self-confident and both convinced that our ideas were right. But as you can imagine, I was always the loser.”
Audi dawn

Then, in 1986, came a call from an Audi head-hunter. The job on offer was not racing specific, but this didn’t bother Baretzky, more of a problem was leaving Bavaria. However, he took the position and so began a three-decade relationship.
There was no racing, Audi having just left the WRC, but the project he became involved in was a five-valve, turbo engine under development for a land-speed record car. The car set some distance records, but more importantly it morphed into the 1988 Audi 200 Trans Am machine; Baretzky was back in motorsport, as was Audi, with its first factory circuit racing project since the Silver Arrows in the 1930s.


Haywood won the 1988 Trans-Am Series in the Audi 200 quattro
Audi


Teething problems with an all-new engine hampered the Audi 90 IMSA entry in 1989
Audi

The 200 was a success with Hurley Haywood and Hans Stuck at the wheel. Its Quattro system gave a huge advantage in the wet but Trans Am banned four-wheel drive for the ’89 season. Audi moved to IMSA with a revised car, and an all new engine, developed in just five months. After a year of teething problems, the car and engine was finally sorted before the 1990 season, but then, the arrival of a new technical director meant IMSA was out and DTM was in.
No turbos

To this point, all of Baretzky’s race engine experience had been with turbo charged applications, but in the early ‘90s, he would begin a period of ‘traditional’ racing engine development, starting with Audi’s entry into DTM. “It was the first time in my life I’d had to deal with a naturally aspirated race engine and the rules said everything we did had to be based on production parts,” reminisces Baretzky.



Creative interpretation of engine regs brought overwhelming success in DTM
Audi
The DTM Audi V8 (the car was named after the engine, the A8 nomenclature would follow later) would prove devastatingly effective, but not without its share of controversy. Up against the BMW M3 and Mercedes 190 the Audi V8 was potent, and, come the final race of the season at Hockenheim, they sealed the title with Hans Stuck. Audi would win again in 1991, but in ’92, growing resentment against Audi’s dominance saw politics come to the fore. “They were always trying to screw Audi down,” bemoans Baretzky. The development that saw this tension come to a head was Audi’s use of a flat plane crank.
To this day, he stands by the legality of the crank and is adamant it stuck to the production parts rules. “The crankshaft is produced by forging. When you forge the production crank it is then twisted in a jig to put the webs in a position you need. For the production car it is a 90-degree orientation, we did the same for the race part, we just twisted it 270 degrees further, a had a flat crank. But it was still the production part!”
Despite rulemakers initially agreeing the part was legal, pressure from other teams saw it outlawed mid-season and ultimately, Audi withdrew from DTM, along with BMW. Global recession almost put paid to Audi’s motorsport programs at this point, but fortunately there was a business case for building cars in Super Touring. This ballooned into Audi supporting cars in eight championships across the globe and, while engine design was still very much on Baretzky’s mind, logistics came to the fore, managing the development and building of over 300 engines a year.

Le Mans

In 1997, Baretzky received a mysterious request from new Audi chairman, Dr Franz -Joseph Paefgen, to travel to England, where upon he was introduced to Richard Lloyd of TOMS Racing Team Norfolk (RTN). “Paefgen then explained why he wanted us there. He said, ‘I have had a dream since I was a boy of 12, I went to Le Mans and, watching the cars, decided that one day I would like to return with my own car. This is now the time. I want to go to Le Mans, and you tell me what you need to win.” So began Audi’s Le Mans odyssey.




Having been deprived of turbocharging for most of the 90s, Baretzky immediately decided Audi’s Le Mans challenger would have a turbocharged V8. The working relationship between Audi and the British crew at RTN, which was building the closed R8C, had its ups and downs, but Baretzky views the period fondly. “Tony [Southgate] and the English guys worked day and night – you can do that with English people and is what I appreciate about working with them. They don’t complain, they just do it. If they come and say ‘we have a little problem’, you can be sure it’s a disaster.”

There were some tense moments, such as the time Baretzky got a call from one of his engineers in England. Someone wanted to drill a hole in one of the engine supports to mount the car’s underfloor. That someone was Peter Elleray and what followed from Baretzky was a torrent of expletives, along with a promise that if anyone touched ‘his’ engine, physical harm would come their way.

The R8 went on to dominate at Le Mans and the engine project laid the groundwork for the Bentley challenger which took the win in 2003. That car was built and designed in the UK, but the engine was all Audi, and behind the scenes, Baretzky was instrumental in Audi allowing Bentley (owned by the VW group) to use its engine.



The winning streak begins: R8s take all the podium places at Le Mans in 2000
Marcel Mochet/Getty Images


The R8 project also saw the arrival of direct injection in motorsport, another Baretzky first. But it was touch and go whether Audi’s system got to debut at Le Mans in 2001. “Dyno running showed the new DI engine to be excellent, with a 10% reduction in fuel consumption over the existing V8,” recalls Baretzky. But problems struck during track testing. “After one hour, we had an engine failure. It was because of a sealing problem with the fuel pumps.”
“I told Audi we should run a diesel at Le Mans. They told me, ‘You’re a good man, but you should not drink so much!’”
Just ten days before Le Mans, there was still no solution. At the 11th hour, an Audi engineer sent to Bosch found that they had a viable seal all along, but by this point, Baretzky had a total of 24 engines sat in a lorry to ship to the track, 12 of the previous years and 12 of the new DI version! “A week prior to Le Mans, we got the new pumps, put them on the engines and drove to Le Mans. I was quite close to killing someone at Bosch at that point. But it worked,” he remembers.
Not only was the new engine more economical, it provided the drivers with much greater control, something Baretzky says was key to the win in 2001, a ferociously wet race. “After the first session, Emanuele Pirro came back to the pits, ran to me, shook my hands and said thank you. What for? I asked. For this engine, was his reply, it is running like an electric motor.”


Diesel days



More than the sum of these parts: components of Baretzky’s V12 diesel engine for the R10
Audi
The innovation of direct injection would pale next to Baretzky’s next move. The ACO had concocted a ruleset to allow diesels to race at Le Mans, a move he was initially opposed to, but then he says, “I was struck by a lighting bolt, I thought f**k, if I don’t do diesel, someone else will and I will regret it for the rest of my life. Audi was the pioneer of direct injected diesel, it was the perfect story.”



The diesel V12 was the power behind three Le Mans wins
Audi
The challenge then was to convince the Audi board. “I went to them and told them I think we should run a diesel at Le Mans. They looked at me and told me, ‘You’re a good man, but you should not drink so much!’”
However, attitudes would change and, at around midnight at Le Mans 2004, in the dramatic setting of the VIP box over the start finish straight, a conversation with Martin Winterkorn (then Audi chairman) and Ferdinand Piech head of the entire VW group, would seal the deal.


Allan McNish nurses the R10 to a debut victory in Sebring
Jean Michel Le Meur/DPPI

Development took place in utmost secrecy and when the R10 was released in 2006, Baretzky’s foresight was proved correct. It dominated on its Sebring debut, despite underlying problems that nearly caused a DNF at its maiden race. Among the tales of incorrectly supplied wiring looms (that meant the engine’s ECU didn’t actually know the crank position) and almost melting pistons. Baretzky recounts an amusing anecdote from immediately after that victory.
He hitched a lift back to the airport with winner Tom Kristensen. “We stopped at the gas station on the way out of the circuit and TK came back with a bunch of newspapers and told me to sort out all of the stories and adverts relating to the race.

From the archive


Audi R10 TDI: 10 out of 10

JUNE 2016 ISSUE
BY GARY WATKINS

“We were driving out of town and he asked me how fast we were allowed to drive. As I said he was probably going to fast, at the same moment, the sirens came on behind us and the sheriff pulled us over. He was a typical American policeman. He told us we were driving too fast, but I said, this is a guy who is paid to drive fast and he looked at me like I was a little mad.
“By chance, I had one of the adverts open, so I pointed and said look, this is the guy who just won the 12hrs of Sebring with a diesel. The policeman paused, then said, sign it, pointing to the advert and then asked TK to sign it. He said, ‘this time, it is ok, but from here to Miami, there are more policemen than you have newspapers, so please, respect the law.’”
Audi persisted with diesel until its withdrawal from Le Mans in 2016, and Baretzky remained convinced of its benefits, despite the best efforts of rule makers to place it at a disadvantage. However, he was less sold on hybrids. “I used to illustrate it like this. I’d put a little glass of water on the table, maybe 3cm of water, and point out this is the amount of fuel that has the same energy as the complete hybrid system. It’s ridiculous. 8MJ was the most powerful system, whereas one litre of fuel has around 40 MJ. But you are carrying along all of the complicated system as well.”


From start to finish: the 1999 Audi R8R and the 2016 R18
Audi

Looking to the future, Baretzky has some strong opinions on the current state of EV development and his favoured solution to sustainable automotive power would be hydrogen, but used in a combustion engine, rather than a fuel cell. “But that said,” he muses, “my time is over and I have done so many things in my professional life. If someone told me I would do them, I would say they are crazy. I have to be satisfied with what I have done and need to leave something for the others.”

CV: Ulrich Baretzky

Born 1956
Studied Mechanical Engineering at University of Munich
1982 Joined BMW Motorsport initially on M5 then F1
1986 Joined Audi, working on engine development for record setting Audi 200
1988 Engine development for Trans Am Audi 200
1989 Engine development on IMSA Audi 90
1990-93 Audi V8 DTM
1993-1999 Super Touring
1998-2005 Audi R8 Le Mans
2001 GDI introduced at Le Mans
2006 Audi R10 Le Mans diesel
2016-present Audi DTM, WRX and other project

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^^^ Full article from link in Post 905

https://www.motorsportmagazine.com/...MmBd4eDtjQQExLiPEYpIjGNY8Kl3dvDkmokvOaQM8qiL8

 

Ulrich Baretzky

 

Step 6 engine ( 1997 )

 

A4 Q STW

 

Why would they need a TAG alternator?

 

Maybe they stll had 100 on the shelf

 

Lol, possibly! Probably more expensive than my GTI

 

Nice rod/piston combo !

 

Going back in time... we talked about angle milled heads, and the exhaust valve that move away from the cylinder wall

The head is milled at 1.5 degree ( and the valves ) so the exhaust valve ( that is normal inline with the cylinder bore ) will now move away from the cylinder wall
as max valve lift on the exhaust 14 mm is...at a 1.5 mm degree angle it will maximum 0.37 mm more away from the cylinder wall
But that is only at full valve lift, so that is only a short period of time ... but on the other end, at low valve lift, would a 0.1 mm increase in distance make a difference ? I tend to think it need atleast 0.2 mm before you start to see a benefit of it...
( btw bore went up from 82.5 to 85 mm and exhaust valve from 28 to 29.5 mm )
All in all, i think the net effect is minimal

The main thing is to get a smaller combustion chamber, this allow a faster burn rate > more power
and as the combustion chamber is smaller. the piston dome can be made less high, so there is less piston weight and and as a result also conrod weight decrease

 

A year later, 1997 laptimes improved by good 2 seconds ....on a 4186 m circuit
Joachim Winkelhock did a fastest lap 1:39.090 in a Bigazzi BMW 320i during a 12 lap race
Johnny Cecotto set Pole Position just below 1:39.000

 

Step 7 85mm bore Piston.