Daytona vs. Boxer

Apples and oranges.

Both good for you, both very different.

 

Ran with a daytona at the track a few years back. From a 40 mph roll on they were basicaly neck and neck at thend of a 130mph straight,

 

Franklin
On the "engine rebuild every 50,000 miles" claim. I'd ask "supported by what?" At our track event last year was a Daytona owned for 30 years by the same owner. 190,000 miles on it. Rebuilt the motor at 120,000. Runs strongly. Has won several events with the car (hill climbs etc).
Philip

 

Frank,

I also have this article. Your post did not mention that this article is comparing a 365 Boxer with a Daytona. Relative to the other thread on old Boxer articles, this seems to contradict the earlier 1990 article that is the subject of another thread. I have come to the conclusion that, due to their smaller displacement, need to rev higher, and sometimes troublesome single disc diaphragm clutch, 365 Boxers are extremely sensitive to setup and weather conditions, and therefore post a wider range of test results than the larger displacement 512s. Anyway, they are all great cars, and let's enjoy them.

Steve Biagini

 

Frank,

What ever happened to John Apen's 365 Boxer? Did he sell it?

Steve

 

I think the Boxer is a beautiful car. A clear connection to the days of Enzo.

That said, as I recall:
(i) the Boxer engine had little relationship to the [then] current F1 engine (which was also a flat 12);
(ii) several versions were campaigned at Le Mans and elsewhere by NART and others; progressive improvement lead to serious changes in bodywork (aero) and rear track [and weight reduction];
(ii) the prototype had the gearbox mounted in arrears of the engine unit, and not underneath it.

The issue: mounting the engine above the trans raised the centerline of the crankshaft to something like 20 inches off the ground and, as a result, contemporary tests of the car (by Paul Frere, Autocar and others) identified somewhat challenging handling at the limit.

Philip

 

Ferrari's road car boxer engine is not really a "boxer" in the traditional sense in which opposing pistons are mounted on different crankshaft throws and therefore move toward each other in a boxing motion. Instead the Ferrari road boxer is actually a 180 degree V with opposing pistons mounted on the same crank throw. I believe that the Ferrari racing boxer engine was a true boxer as is the Porsche 911. I have to confess to not knowing the technical significance of this difference. Maybe some F-Chat mechanic or engineer can elaborate.

 

I have that article. 50K miles between engine rebuilds on a Daytona? What nonsense! Perhaps if its 50K miles of racing....

As to the other points relative to performance comparisons.... well, we will just have to find out now wont we?

My Daytona is just about back together. Since Frank and I will be driving down to the French Quarter classic together, he in his Boxer and me in my Daytona, I do believe we will have the opportunity to do some performance comparison testing of our own.

My money is on the Daytona, but we shall see. Betting anyone?!?!?!

My only concern about the Daytona winning a 0-60 (or perhaps better... 0 - 100) type run is that the Boxer is likely to hook up better at the start. Wheel spin with the Daytona is a big issue if you slip the clutch at over 2500 rpm.


Terry

 

What?

 

Who is making excuses???

Stock? Stock what? What about Stock? I dont own any stock?

Excuses, Excuses.... Daytona HP is 352, 512BBi is 380 I believe. Shouldnt the lighter car with more hp have a clear edge?

We shall see..... Muhahahahahahahahahahhahahaha



Terry

 

It would be helpful if you were more specific with your question. But, to reiterate, a true boxer engine is one in which opposing pistons move toward each other with each firing (e.g, they are moving in opposite directions). This can only happen if the connecting rods for those pistons are connected to different crankshaft throws. If they are connected to the same crankshaft throw, then the piston pair will move in the same direction (e.g., one chases the other). The Ferrari road boxer engine has the latter configuration as do all of Ferrari's other road engines.

 

Frank,

I thought we already covered this, but there is no way the 365 Boxer, with the same displacement and revving capability as the Daytona, had only 300 hp; unless, of course, the Daytona only had 300 hp. However, this cannot be the case since the extensively documented road tests of the Daytona illustrate performance figures that are at least the equal of any Boxer. And of course there are the much fewer road tests of the 365 Boxer, but of which I have pointed to two which achieved top speeds of 175 and 173 mph, a pretty good indication of power at least equaling that of the 512 Boxers.

Remember, an internal combustion engine is nothing but an air pump. The amount of air/fuel mixture pumped through its system determines the amount of power it produces. The factors that determine the quantity of this flow are displacement, flow efficiency, ability to rev, etc. Also remember that the 512 Boxer engine was enlarged in an attempt to preserve the performance that would otherwise be lost in meeting the new for 1976/7 European emission and noise standards. Since these engines had to burn cleaner, they were allowed less valve overlap and, could not rev as high. The later Testarossa engine overcame this problem by using 4-valve technology to allow more air/fuel mixture into the cylinders, but the 512 boxers did not have this luxury. As a result, the increase in power coming from the 4.9 liter displacement and slightly higher compression was offset by the inability to rev as high. If displacement was the only factor, then the F355 with only 3.5 liters of displacement would not be able to produce a real 375 hp.

Now for quoted horsepower figures. Here Ferrari has confused matters by using DIN and SAE net at different times for the same car. This practice seemed to be common at Ferrari in the 1970s. The difference between DIN and SAE net horsepower is approximately 5 percent, with the SAE net figure being the lower one. The 380 and 360 hp figures that were quoted for the 365 boxer were DIN figures. The 380 was the level achieved by the prototype 365 Boxer and it was incorrectly used in the press release literature. The 365 engine was detuned to 360 DIN for production, which translates into 344 SAE net (@7200 rpm). This is the level that is quoted in my 365 Boxer owner's manual. I also have a 512 BB owner's manual which lists the hp as 360 DIN @ 6200 rpm, or essentially the same power output but at a lower rpm. I do not know if the 340 hp for the 512BBi is DIN or SAE net but I believe that it is achieved at 6000 rpm. I am not absolutely sure, but it is my belief that the Daytona's 352 hp is a DIN figure, so the SAE net figure would be about 5 percent lower.

I have done extensive research on this subject and my mind is now cluttered with facts that are probably irrelevant and boring to 99.99999% of the human population, but I feel fairly confident of their accuracy.

Steve

 

In Niki Laudas book he stated that they made motors in both configurations. Despite the block configuration they referred (internally) to the motors with rods sharing a crank pin a "V12".

 

I'll see if I can find and post the references I indicated. I do not believe either of your points is quite accurate, but, let me "put up or shut up".
Philip

 

Jeff
Interesting, please post the quotations when you next have the book to hand.

On engine layout, I am referencing from Antoine Prunet's book, "The Ferrari Legend: The Road Cars", written in 1981. In the acknowledgements section he sources Pininfarina, Michelotti, Ghia, Zagato, Bertone and, of course, Ferrari. On page 432 of same, Prunet writes of the 365 BB: "Because of space limitations the transmission could not be placed at the rear of the engine, as on the prototypes."

On racing engine/road engine, in Keith Blumel's book, "Ferrari, the road cars", published in 1998, on page 107, beneath a picture of the 365 BB, he writes: "The 365GT4/BB, the BB standing for berlinetta boxer, with the "boxer" part of the name referring to the firing sequence of the flat-twelve engine. The Ferrari flat-twelve racing engines were true boxer engines in that the opposite pistons on the crankshaft moved together and away at the same time. On this production engine, one piston moved away as the other approached, so there was a degree of artistic licence in the name."

As I said in my first post, however, I believe this are great cars. For me, Paul Frere captures the spirit well: [Prunet goes on to quote Paul Frere, from Sportmoteur on page 436] "The session on the Fiorano circuit was a true pleasure, the available power always being sufficient to exit the corners with a great deal of acceleration, after breaking the rear wheels loose in a well controlled slide...Without being particularly light, the rack & pinion steering was very agreeable, moderately demultiplied and very precise. In this respect the BB is certainly a great improvement over the Daytona which, because of the weight of the engine on the front wheels, had a harder and slower steering and therefore was slightly more tiring."

If you don't know the Prunet book, it has wonderous detail on prototypes, converted race cars and, of course, the production vehicles.

Philip