Hydristor push-to-pass

[riff_raff]

Belatti,

Your point is well taken. There are lots ways to improve efficiency with an internal combustion engine powered automobile. The easiest, and most cost effective, are to reduce vehicle weight, maximize mechanical efficiency and minimize aero drag losses.

Reducing weight costs money. But optimizing mechanical efficiency and reducing drag losses can be implemented for virtually no cost. All it takes is good, creative engineering.

Unfortunately, improving the brake thermal efficiency (BTE) of modern internal combustion engines is also quite costly. The BTE of a modern, automotive diesel engine, at about 35%, is actually quite good. Getting another 3% or 4% beyond that is possible, but would easily double the cost of the engine. Diesels are more efficient than gasoline engines, but the $1000 to $2000 cost premium is currently unacceptable to the typical buyer (at least here in the US).

Improving the efficiency of the transmission from, say 94% to 96%, is the most cost effective change an automotive OEM can make. That 2% gain in transmission efficiency correlates directly to a 2% gain in fuel economy. That is why most automotive OEM's are working hard to get 6-speed or 7-speed AMT's or DCT's into production. They are less expensive than a conventional automatic transmission, and they have about 97% efficiency (vs. about 94% efficiency for a conventional automatic).

[Ciro Pabón]

Sorry, guys, for bumping this thread (complain to Tomba, is useless to report this to me).

Check this:

The “Would–Be” Interview With John DeLorean

Two weeks before his death in March of 2005, I had a conversation with John DeLorean, the storied GM exec, design chief, and creator of the GTO (Gran Turismo Omologato) at GM during the muscle car era.

The reason for the conversation? At the time I was talking with an inventor named Tom Kasmer who was requesting an interview on my national radio show, America’s Car Show. Tom had developed a new hydraulic vehicular powertrain called the Hydristor. He claimed that John DeLorean was going to use the Hydristor as the powertrain in his new car that was slated to roll out from his resurrected corporation, DeLorean Motor Company (DMC). I told Kasmer that if he could have John DeLorean call me and confirm that this was true, then I would have him on the radio show. I had received other similar calls in the past, so I forgot about this one as soon as I hung up the phone. The next afternoon I received a call from a NYC number I didn’t recognize. The voice on the other end introduced himself as John DeLorean and asked to speak with me. I was surprised, to say the least. For about 20 minutes we talked on a few fronts (while a friend of mine sat in my office with his mouth agape and pie-eyed) and then we scheduled a live on-air interview for three weeks later in early April; however, two weeks later he died. I had put together the interview questions a week of so after our phone conversation and saved it filed under the title: “The “Would-Be” Interview With John DeLorean.” Below are the questions I was going to ask John. The answers are what I thought John might have said based on our conversation two weeks before his death.

TT: John, regarding the creation of the GTO - the story goes that one Friday you were sitting in the design studio at GM and wanted to drive something exciting that weekend but could not find anything compelling. So you found the smallest car in the stable, stuck the biggest engine you had in it, and drove off into history with the creation of the GTO. Is that about how it happened?

JD: Well Tom, history and the facts always do differ. So here’s how it really happened. Yes, it was a Friday afternoon and I was trying to decide what to drive that weekend. As I looked around the design studio, I realized that there was nothing in the lineup that I wanted to drive. I wanted something sporty and powerful so I looked at the Tempest, which was the smallest car we had in the lineup. Then impulse took over and I had my team find the largest engine we had in inventory at the time (389 CID that was used for the Catalina and Bonneville) and install it in the Tempest. I drove the car for the weekend and LOVED IT! So I decided to loan it to other GM execs. This was a dangerous move to my career at the time because GM had issued a ban on factory-sponsored racing. To get them to drive it, I said that the car was designed for street-racing, not professional racing. They took the bait and test-drove the car with that understanding. I knew I had something when I had a hard time getting the car back from them, and hence the GTO was born.

TT: Fascinating story. The GTO led you to Pontiac division President in 1965 at 40 years old, the youngest GM exec to date. You built Pontiac to a strong position and then took over Chevrolet when Chevrolet was having trouble. You reorganized that division and made it profitable too. As a result, GM promoted you to VP of national car and truck division, in effect a stepping-stone to the GM presidency. But you left GM shortly after that. Why did you leave GM before reaching the pinnacle of power?

JD: Too much bureaucracy and red tape at that level. It’s hard to overcome traditional values and ways of doing business. I figured I’d open my own car company where I had full reign.

TT: Hence the creation of the DMC corporation?

JD: Yes.

TT: History records that DMC had a short run and closed due to economic, legal, and quality control issues. Is this true?

JD: Yes.

TT: I understand that you are in the process of re-launching the company. Will the car you’re selling be built on the same platform as the DMC car of old?

JD: We’ll use the same platform and look, a Renault powerplant; and as an option, some vehicles will come equipped with the Thomas Kasmer Hydristor hydraulic hybrid system.

TT: Really? The Hydristor? And what about the signature gull wing doors?

JD: Yes, the Hydristor has wonderful potential as a hybrid powertrain and would be a perfect fit in our new cars. I have looked at it both from an engineering and marketing standpoint, and am very excited about the potential this system has to offer our DMC vehicles. We are looking at using carbon fiber and fiberglass panels to lighten the car, high performance suspension and steering systems, a high performance Renault powerplant, and yes, gull wing doors.

TT: When can we expect to see the new DMC cars roll off the assembly line?

JD: Sometime next year.

TT: Thanks John.

JD: You’re welcome, Tom.

[WhiteBlue]

Hydristors are noisy and low efficiency. Ok, for big and slow vehicles.

[Ciro Pabón]

They are noisy, ok. However, they have a very good efficiency (according to tests by Tom Kasmer), around 98% if I remember well, much better than a regular gearbox.

[autogyro]

They are noisy, ok. However, they have a very good efficiency (according to tests by Tom Kasmer), around 98% if I remember well, much better than a regular gearbox.

A torque converter with a lock up clutch is better, in fact when locked the converter is 100% efficient. The transfer of torque is what is being quoted for the hydristor and like most such claims conveniently ignores other losses. Such claims are almost irelevent. A conventional auto box with converter locked in top gear is 100% efficient by direct comparison.
The first problem of the many problems with the Hydristor is just how big and heavy do you want to make it. If you are expecting it to replace a gearset by moving fluid under pressure, then you need at least as much oil 'volume' as a conventional non lock up torque converter plus a lot more, otherwise you will be unable to cool the oil. This would be at least 20 litres of oil in a small vehicle and a great deal more in bigger vehicles. The hydristor also works at a far higher pressure than a turbine, impeller and stator (one way clutch) based torque converter, so needs to be a lot stronger. The result is that the system becomes big bulky and heavy and not even as efficient as a simple fluid link fluid flywheel. The fluid flywheel link was fitted to the 'hydromatic gearbox' designed and used by GM this was probably the best thing they have ever done. It was fitted in pre and post war GM cars and in wartime vehicles like the Bren gun carrier. It was made in a four speed version when fitted to the British Vauxhall Cresta as built in the early 60s, it was brilliant and only taken out of production because it never went wrong. Now that 'was' an efficient transmission.
Six cylinder 2.2 litre big saloon over 100mph and better than 35mpg around Town. Better than almost everything available today, I wish I still had mine. The powerglide and turbo hydromatics that came later were rubbish by comaparison.

Hydristors also have high tip wear on the internal seals because of high oil pressures and the centrepedal force that torque converters do not suffer from.
As soon as there is even a little blow by internaly the efficiency in transfering torque drops through the floor. Anything over about 50 miles from new will result in this.
All the above does not even start to explain the losses in the control system that is needed to achieve a constantly variable range of ratios. Just like all CVT concepts the energy needed to vary the pressures and flow rates in a Hydristor far outway any benefits in torque transfer.

[autogyro]

They are noisy, ok. However, they have a very good efficiency (according to tests by Tom Kasmer), around 98% if I remember well, much better than a regular gearbox.

A torque converter with a lock up clutch is better, in fact when locked the converter is 100% efficient. The transfer of torque is what is being quoted for the hydristor and like most such claims conveniently ignores other losses. Such claims are almost irelevent. A conventional auto box with converter locked in top gear is 100% efficient by direct comparison.
The first problem of the many problems with the Hydristor is just how big and heavy do you want to make it. If you are expecting it to replace a gearset by moving fluid under pressure, then you need at least as much oil 'volume' as a conventional non lock up torque converter plus a lot more, otherwise you will be unable to cool the oil. This would be at least 20 litres of oil in a small vehicle and a great deal more in bigger vehicles. The hydristor also works at a far higher pressure than a turbine, impeller and stator (one way clutch) based torque converter, so needs to be a lot stronger. The result is that the system becomes big bulky and heavy and not even as efficient as a simple fluid link fluid flywheel. The fluid flywheel link was fitted to the 'hydromatic gearbox' designed and used by GM this was probably the best thing they have ever done. It was fitted in pre and post war GM cars and in wartime vehicles like the Bren gun carrier. It was made in a four speed version when fitted to the British Vauxhall Cresta as built in the early 60s, it was brilliant and only taken out of production because it never went wrong. Now that 'was' an efficient transmission.
Six cylinder 2.2 litre big saloon over 100mph and better than 35mpg around Town. Better than almost everything available today, I wish I still had mine. The powerglide and turbo hydromatics that came later were rubbish by comaparison.

Hydristors also have high tip wear on the internal seals because of high oil pressures and the centrepedal force that torque converters do not suffer from.
As soon as there is even a little blow by internaly the efficiency in transfering torque drops through the floor. Anything over about 50 miles from new will result in this.
All the above does not even start to explain the losses in the control system that is needed to achieve a constantly variable range of ratios. Just like all CVT concepts the energy needed to vary the pressures and flow rates in a Hydristor far outway any benefits in torque transfer.

[autogyro]

Also to state the complete background.
I have never bought any Cocaine from Mr DeLorean but I do know all the stories.
I suggest you view his comments with a pinch of salt.