Boxer and TR transmission (loss?) technique - Ferrari Life
 
LinkBack Thread Tools Display Modes
post #1 of 10 Old 11-26-2009, 11:34 PM Thread Starter
Owner
 
212Export's Avatar
 
Join Date: Oct 2007
Location: Europe
Ferrari Life Posts: 3,996
Boxer and TR transmission (loss?) technique

When studying the rather special transmission technique of all the flat 12 cylinder Ferrari models (365BB, 512BB Testarossa, 512 TR, 512 M) I was wondering how much power actually is getting lost from the initial crankcase power until the power is transmitted thru 2 or 3 90 degrees angels to the axles of the wheels.
This technique shortens the car's lengths measurements considerably as a plus but I'd believe that the loss of power is there as well (besides the point of gravity, which is quite higher engine and gearbox wise) compared to a technique of having the gearbox straight behind the engine (i.e. 250 LM or F50).

Any ideas or knowledge on this out there ? Thanks.
212Export is offline  
Sponsored Links
Advertisement
 
post #2 of 10 Old 11-27-2009, 04:30 AM
Administrator
Owner
Elite Member
 
Boxer's Avatar
 
Join Date: Apr 2004
Location: UK & Texas
Ferrari Life Posts: 15,136
Great question and no idea. What is the power difference between the Daytona and 365 BB?
Boxer is offline  
post #3 of 10 Old 11-27-2009, 04:36 AM
Owner
 
Italian Lover's Avatar
 
Join Date: Feb 2005
Location: Far end of the P pond
Ferrari Life Posts: 6,738
Quote:
Originally Posted by Boxer View Post
Great question and no idea. What is the power difference between the Daytona and 365 BB?
Not sure how accurate the figures are, but just checked some books and 365BB claims 380HP @ 7200rpm and Daytona claims 352HP @ 7500rpm. w/ smiles Jimmy

Last edited by Italian Lover; 11-27-2009 at 04:37 AM. Reason: s
Italian Lover is offline  
 
post #4 of 10 Old 11-27-2009, 05:04 AM Thread Starter
Owner
 
212Export's Avatar
 
Join Date: Oct 2007
Location: Europe
Ferrari Life Posts: 3,996
I'm not sure that the raw comparison of power between the 365 GTB/4 and the 365 BB would answer the question. They have the same engine volume but have different engine layout's as well as I have no idea if i.e. the cylinder heads (comb. chamber) have the same dimensions, shape etc.

Just the raw mechanical fact that on the 365 BB the crankcase power is transmitted by 2 90 degree gear (cog?) wheels and severeal intermediary wheels just to end up at the beginning of the gear box makes me think that on each contact and joint, power must be lost, naturally. Whereas theoretically, a straightline transaxle has no joints to loose power (except at the clutch and gearbox joints, which we did not even started to mentioned in the case of the 365BB)

That is probably also an explanation why the 380 (official) HP on the dynobench tested for the 365BB (Official Ferrari factory statement) naturally goes down to maybe a more realistic 340 HP measured at the wheels. This difference used to be a very prominent debate of the pro and cons for the 365 BB in time.
212Export is offline  
post #5 of 10 Old 11-27-2009, 05:08 AM
Owner
 
Join Date: Dec 2003
Location: Michigan
Ferrari Life Posts: 308
There are so many factors that can affect power loss, so many variables, that we can only guess .....er..."predict" what the parasitic losses are. I would think that the losses are comparable between the flat-12 layout and a conventional layout, somewhere around 18% or so. Some dyno tests with TRs show rear wheel horsepower around 315hp to maybe 325hp. Ferrari rated the U.S. version cars at 380hp. So the math shows the loss at about 16%. This is just my 2 cents.....and it probably ain't worth that much....
carguy is offline  
post #6 of 10 Old 11-27-2009, 11:50 AM
Administrator
Owner
Elite Member
 
Boxer's Avatar
 
Join Date: Apr 2004
Location: UK & Texas
Ferrari Life Posts: 15,136
Anyone know the rear wheel bhp number for the 365BB?
Boxer is offline  
post #7 of 10 Old 11-27-2009, 12:14 PM
Owner
 
Italian Lover's Avatar
 
Join Date: Feb 2005
Location: Far end of the P pond
Ferrari Life Posts: 6,738
Quote:
Originally Posted by Boxer View Post
Anyone know the rear wheel bhp number for the 365BB?
Sorry, Boxer,...not sure what bhp is, but is it this spec. ? wheel+tire: F/R 7.5L-15+215/70VR15. w/ smiles Jimmy
Italian Lover is offline  
post #8 of 10 Old 11-27-2009, 02:30 PM
Owner
 
Neonzapper's Avatar
 
Join Date: Jan 2009
Location: D.C./Manila
Ferrari Life Posts: 1,008
Quote:
Originally Posted by Jimmy Chen Shiba DDS View Post
Sorry, Boxer,...not sure what bhp is, but is it this spec. ? wheel+tire: F/R 7.5L-15+215/70VR15. w/ smiles Jimmy
bhp = brake horsepower of the engine.

What you described is a front right tire on a 15 inch rim. Since you put "with smiles" I'm guessing you were either kidding, or promoting your dental practice

_________________________
Neonzapper is offline  
post #9 of 10 Old 11-27-2009, 03:11 PM
Owner
 
Italian Lover's Avatar
 
Join Date: Feb 2005
Location: Far end of the P pond
Ferrari Life Posts: 6,738
Quote:
Originally Posted by Neonzapper View Post
bhp = brake horsepower of the engine.

What you described is a front right tire on a 15 inch rim. Since you put "with smiles" I'm guessing you were either kidding, or promoting your dental practice
Thanx, Neonzapper. The truth is, simple ignorance on my part. Thank you for the enlightment. Jimmy
Italian Lover is offline  
post #10 of 10 Old 11-28-2009, 02:47 AM
Owner
 
JazzyO's Avatar
 
Join Date: Feb 2007
Location: The Netherlands
Ferrari Life Posts: 6,397
Quote:
Originally Posted by Boxer View Post
Anyone know the rear wheel bhp number for the 365BB?
I've never seen 1 specific number. If we take the more or less accepted figure of 344bhp (the 380 figure was only achieved on a pre-production engine but it seems Enzo did not want to release a number lower than the Daytona's) and we use 15% loss it would be 292bhp. I would not be surprised if it was less. The dynoed 365 on ferraricraft.com developed 326 bhp at the engine, so that would be more like 270 bhp at the wheels, perhaps even 250 if you consider the losses might be greater. Excellent point, by the way, 212export, you would expect the transfer points to contribute to losses.


Onno



Never pay again for live sex! | Hot girls doing naughty stuff for free! | Chat for free!
JazzyO is offline  
Reply

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome
Copyright 2012 ONE Media, Inc.
FerrariLife is independently run with no affiliation with Ferrari SpA
Ferrari for Sale | Maserati for Sale