No Biturbo Thread?

Plenty on here on Biturbos if you poke around. I had a 1989 Zagato Spyder 5 speed for some years. It was a great car, and my wife especially liked it. Parting was such sweet sorrow, as they say. The FI 2.8L in the 1989 cars was quite robust, and boy could it scoot. The only this I didn't care for was the alcantara on the seats, but a relatively minor point. If I were to get another biturbo, the 89 Spyder stick would be it.

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John, the pre 87 cars problems were all DeTomaso's fault but he really did have an impossible task. They never finished developing the cars before selling them. He did the same thing with the Pantera. There were reasonable fixes for most of the issues but here in the USA the dealers couldn't make those changes due to federal regulations but owners could which is what I did extensively and eventually many others did the same. You're not going to easily find one of those. Mostly you'll find cars that have had butchered up "fixes" so post 86 cars with the FI are your best bet. I think all of those have the watercooled turbos which is a must. The 5Sp ZF which used well into the 90s is too weak to handle any power tuning as are the early clutches When they went to 6spd Getrag they were using the same boxes found in same year M3s. The very early 5sp ZF had a tendency to pop out of 1st gear. That happened to me a dozens times in SF until they replaced it under warranty. That's about the only supplier failure I'm aware of.

But biggest issue was the poorly designed emissions systems. That effected all Maserati's GT cars, QP3 and Biturbos through 86. Lots of cars burned up and if it wasn't that then it was the excessive heat causing component failures, especially the ignition components.

 

Cozza has a passage in his book about how he verbally beat on DeTomaso about the carbureted biturbo engine in the dyno room, essentially stating there was no way it would work as it should and they needed to inject it first. That of course fell on DeTomaso’s deaf ears who almost fired Cozza for that outburst.

Marelli came up with the injection system and all was good, but it was too late. It’s my understanding the injection system was very similar to the F40 and 288GTO

I like the 4v v6s in the Ghibli II

 

My shop in the mid-80's to mid 90's was a factory authorized Maserati service center. We kept half of LA's Bi-turbos on the road. The dealer sold a lot of cars but had only one mechanic so they sent us all their problems to sort out and fix. The dealer mainly did routine service or something minor. We did the bigger more complex jobs.

One thing we never lacked of in those years --- cars to fix!

Replaced a lot of fuse boxes in those days. Water pumps and turbo's as well.

 

What you guys are getting wrong is that it is possible to make a carb in a box car work wonderfully, even in hot and very cold weather, just not emissions legal. That meant the dealers never could. I'm going to guess that's what the factory did too initially and DeTomaso liked those results but it was when the USA emissions had to be passed that all the trouble began. Well actually earlier than that because the GT cars with thermal reactors and air pumps didn't work either and when they put the catalysts with air pumps on the QP3 that was also a failure. Cars caught on file, carpeting melted oh it was a spectacular mess. You see, when the well heeled ladies in San Francisco from the Pacific Heights & Sea Cliff neighborhoods started their gorgeous, luxurious and exclusive chariots they would sometimes need to utilize the manual choke for a while so that the car started and ran smoothly. That's something they hadn't had to do since the mid 1950s in Cadilliac, Lincoln or Jag or even a RR. So being so disconnected from how cars work they forgot to close the choke which fed an overly rich mixture to, the engine and catalytics. FIRES! It wasn't just the ladies either. For years there were burn't out QP3s on British Motor cars parking garage roof. They were the Jag, RR, Maserati dealer for decades there. They were also the west Coast distributor in partnership with DeTomaso.

But proper mixture with a supercharged carb in a box will always get trumped by a good FI system. I dealt with the mixture issue in a couple of different ways.
My car has the Spearco liquid intercooler system which when running well can generate very nice HP and an enormous amount of torque for a 2.5 liter engine. But that means never letting it go lean. So I spent an inordinate amount of time jetting that carb until I got a setup usually delivered fantastic levels of power for the time. With an overly stiff suspension kit from MIE I embarrassed Testarossas, Panteras, and Countachs at the track up to about 120 mph but on a very long straight I was pushing an aerodynamic brick through the air! 140 mph was about most I ever saw and that was in Nevada after a very long run. 0-60 was 5.4.

However, it can get quite cold in N California in the winter. The intercooler system had a plenum pressure switch which would turn on the circulation (bilge) pump under boost but that always lagged behind the need to cool the charge so I replaced that with a vacuum switch to get the pump circulating earlier on the transition from vacuum to boost condition curve. WO that mod you would always get an annoyingly odd second surge of power from the very well cooled reservoir of radiator water.

In the winter the mixture was too rich and the performance was periodically dull so I would turn the circulation pump off via a switch under the dash. The combination of Off, On via pressure rising and Full on served me pretty well.

The dual ECUs were indeed the same Marelli units as utilized in the F40 and by the time the Maserati got them they were obsolete so Marelli gave DeTomaso a deal, he loved deals ...

 

One of the biggest problems was getting cars to pass through CA smog tests. We had a gas analyzer but they were temperamental. . We lost money on each one but knew if we didn’t get it passed thus was another customer we lost as they would trade it in. We had cars with 2nd and 3rd owners. People would sell them and they would show up again.

Doing a valve adjustment is a pita. Unlike Fiat and Ferrari that used shims, Maserati had stem caps.

if we lost an ECU, we replaced it with a Buick V6 module from NAPA. Ran perfectly and saved the customer $$$. This was before the internet so we were on the phone every day with MIE ordering parts. They became a great resource of what they were seeing out there.

I can tell you also the shop hour to repair was complete BS. Qvale messed with the hours. After they went off warranty we could charge true hours. We found all kinds of tricks to shorten the time. We passed those savings over to customers so they would keep their cars and come back.

Towards the end we had people who brought the car in they paid $3000 for. Looked amazing—but with serious issues mechanically. Most of these cars just disappeared and were scrapped. I had one customer who dropped it off, got the estimate, and never came back.

IMO the best were those with manuals and the 425. The car was really helped with Fuel Injection, even if it was Marelli instead of Bosch.

 

A big advantage I had was a residence in Calaveras county so no emissions check. That also helped me get my Bora registered in California. You can't do that anymore there which is why anything after 1976? cannot be registered there. Thus I could do all sorts of modifications that dealers could not.

 

Little bit of a reprieve now with Leno's law though no?

 

I've heard of customers just dumping their biturbos with shops many many times! Those cars/engines eat some hours to get going and it just is what it is. The Marelli injection system is the same used on the F40/288 no?

The shim under bucket situation makes for laborious valve adjustments! Ugh. I've just completed my 9th 3.3L Merak SS engine and even with the engine apart on the bench it takes 4-5 hours to shim the heads. Ducati 8mm opener shims are what fits and at least they have a vast array of thicknesses available and they are consistent.

The Buick module trick is a good one, I've seen it with some Merak SS engines as well, although the Bosch Merak SS distributor fires an MSD box just fine, just needs a tach adapter, works great though otherwise. The modern MSD 6al2 is an even better option as you can program your own advance curve (stock Maserati curve is very lazy). Just lock down the distributor advance and program it on a laptop or the MSD app with your phone. What a time to be alive. I believe a number of Dino fellows have one of these boxes or a similar one stuffed into the Digiplex box and it works aces.

 

I'm not sure. If he's managed to truly tame the arsehole bureaucracy at CARB that just might put Leno in the automotive hall of fame amongst, oh wait he's already there!

 

The Biurbo engines were "developed" by Cosworth there's a lot of their design technology. Cosworth actually made the 4V heads which is why their valve shims fit. I had a lot of work done at vintage race engine gurus's shop in PA. He supported so man vintage racing efforts. He was a formula 1 & 2 race mechanic and he had some very interesting engines in his shop. He let me set my valve clearances for my 2.0 4V 6 cylinder Ghibli Open Cup engine after he had line bored 3 of 4 cam bearing journals. I had ingested parts of a Viper suspension and that took out one of the turbos but I didn't realize until the undamaged one spun itself to death compensating for the pressure loss. It had a dime size hole in the compressor housing from the Viper debris which I couldn't spot or detect until it was too late. What a mess. So he got to learn about that engine and recognized it's Cosworth architecture.

BTW on the street cars with Cosworth engines they used the same Marelli ECUs.

One of the fellow GOC owners is an engineer at Mclaren and he's adapted one of the tools on the market place for querying those ECUs. Maserati's tool was a dipwad harness with push buttons and colored lights that didn't tell one very much if it worked at all. Eventually I tapped into the ECU's harness and installed a dataloger do I could email them to my engine builder to analyze my runs at Watkins Glen.

Some of his fellow engineers worked on these cars/engines at Maserati.

 

Yes. And Diablo. Actually its pretty good system but the diagnostic tools expensive.

If I remember correctly we could get Marelli Fi parts from MIE also or GT Car Parts. But like most Fi of the time, they didn't have much to go wrong.

For Bosch we could get everything delivered in hours from WorldPac. For Alfa most of my parts came from Alfa Ricambi in the Valley.

 

I had one elderly customer who had a BiTurbo Zagato convertible. He and his wife would drive it. Beautiful red with cream interior. They were basically all automatics. We serviced that car for him an his wife since new. Anything even remotely wrong he brought it in. This went on for years.

One day he said he wanted to sell it. He tried but no one would even look at it. Even as a trade he would only get $3000. So he offered it to us for $3000. We bought it, drove it for about 6 months to a year, and got rear ended at a stop light. The insurance company just totaled it without even looking at it. In the late 90's that was the unfortunate state of the Bi-turbo.

We serviced a good amount of Quattroportes. That car I really liked. You have to sit in one. Some of the Bi-turbo interior is based on them. So cushy! And pretty reliable. The engines are bullet proof, gearbox I think was GM but we never replaced one.

 

I have fallen behind!
Here is one:
https://www.ferrarichat.com/forum/threads/the-biturbo-market.610950/

Here is mine:
https://www.ferrarichat.com/forum/threads/my-89-spyder.535840/

 

I am approaching year 10 of Biturbo ownership. I also have the 1985 carbureted E model with the exotic Spearco air-to-liquid intercooler system. The car has given me no major headaches (plenty of minor ones). It is a blast to drive when I don't want to contort my 6'3" frame into the 308. It is every bit as exotic as the Ferrari.
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Can we assume that the emissions equipment has at least been bypassed? Which car is that in the photo?

 

The car in the photo is mine. I have had the car smogged in 2016, 2018, 2020, 2022, and 2024. It has the original CA blue plate. It has always passed smog with flying colors. Last year just for laughs I decided to remove the cat and smog pump. No appreciable performance gain though it sounds a little bit nicer (for a turbo).

 

So it's a FI car or what and which MY?

 

It's a carbed car, MY 85.

 

rare bird with the air-to-water intercoolers, I believe only California market E's got them

 

Yes that was my understanding though I am still trying to figure it out. Some had intercoolers with the trident logo, some (like mine) did not. The intercooler placement on the later Si was an improvement. Image Unavailable, Please Login Image Unavailable, Please Login

 

I'm fairly confident the water to air is a more efficient intercooler all day. The air to air they changed to later was just easier to do, they just tossed them in front of the radiators.