No Biturbo Thread?

I know these cars like the back of my hands so is your car typically operated WO the air pump connected and only for smog tests? Answer via PM as you may not want that answer on a public forum.

 

Well the air to water design takes advantage of the greater efficiency cooling with the water but there is no free lunch. So if you're pushing the engine hard say around a tight racetrack or flat out for many miles the entire system, heat exchangers and water heats up it with no down time for the water to cool down enough to provide the superior cooling effect it has on more intermittent loads. Typical driving will work very well with the air-to-water system thought you do get what feels like a secondary surge of torque once the very cool water in the radiator up front gets circulated through those Spearco units via the bilge pump which is turned on via the original pressure switch as boost rises. That's one reason why I changed that switch to a vacuum switch to so as to get the pump going earlier on the boost development curve.

 

Changing to a vacuum switch was a great idea!

It's an interesting topic, and it's sort of all over the place in F1 with the future pointing to everyone being W2A as most have been. The last dozen years or so, Ferrari have been running water to air, likely because water to air can be so compact. Mercedes also ran a W2A cooler, but Mercedes customer teams chose to run A2A at first. Then in 2022 the regulations allowed 3d printed W2A coolers, so Ferrari, Mercedes, and Alpine all ran W2A, except McLaren who ran A2A. Red Bull have always run A2A with Honda. W2A is heavier, but is overall less volume to install as the radiator doesn't have to be nearly as large as A2A units to be efficient.

 

I've been too scared by the reliability reputation to ever think about buying a Bi-Turbo, but I've always admired them. I love sleeper cars like this that are very subtle in design, while being special and rare, with great performance. A manual seems like a perfect car for to enjoy daily. Are those seats and interior as comfortable as they appear?

 

Yes. They are by far the most comfortable seats I've ever traveled in. When you get out of the car after a long drive nothing hurts. They spoil you for all other cars. The downside is that they are conducive to sporty driving. You have to modify these cars and then they are quite reliable but setting valve clearances is a SOB, fraught with potential disasters. You also have to do all the yourselves as there's almost no one who knows how to work on them or have the patience to do the job the way it should be done.

I've helped to run one of the longest running and earliest website BiturboZentrum and I've seen so many people who buy a nice looking example then end in disappointment, disgust and disaster.
I am unable to work on mine for a couple of years now and so I'm contemplating teaching my Jag mechanic how to replace the water pump by being there while he does the work. I'm not sure how this will work out but he works on a lot of different stuff. He's a racer, race mechanic and does very well on modern cars as well. You really do need to modify the suspension if you have the liquid inter-cooled car or you'll kill yourself.

This guy knows how to work on them but he's retired. The shop has been taken over by someone else https://www.daveburnhamcitroen.com/
He turned an 84 or 85 coupe into a race car.

 

Thanks for the detailed info. I think I'd really enjoy owning one, but I'm probably past the point in life where I want to work to maintain a car. Some less reliable older cars can be made better with aftermarket improvements and known remedies, but some remain difficult to fix. Sounds like Bi-Turbos are (like vintage Lotuses) in the latter category.

My son just got a used Giulia Ti Sport AWD and it's had some stupid issues (plastic radiator & intercooler coolant bleeders, plastic coolant lines), but hopefully will be reliable with the known ares fixed. It's an amazing car otherwise.

 

I had an 84 Quattroporte as well as 3 V6 Alfas. The Biturbo is no more or less reliable than any of them. They are not worth restoring but the survivor cars are definitely worth seeing out and saving. The interiors are simply amazing, even on the older versions.

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