Ferrari 550 Maranello Rear-Wheel HP?

If work around the average 33% drivetrain loss like most front engined/rear wheel drive cars.......

I would say they have around 325 HP at the wheels. Give or take a few HP.

But I cannot confirm that number, or the 33% drivetrain loss. I dont know how efficient the Ferrari 550/575 driveline is??

But it would be close to that number. Also, dyno's vary from dyno to dyno.

 

33%? thats pretty high. most are 15%ish

 

I agree, 15% loss should be about right.


Darrell.

 

Well, my friend owns a Dyno Dynamics chassis dyno and he reckons that most front engined/RWD cars experience an average 33% drivetrain loss. Just an average he said. I dont see why the 550 would be any different?? Front engine, clutch, driveshaft, gearbox/diff/axles.

My 348 (transaxle) experienced a 15-18% drivetrain loss on the same.

I could be wrong as it was just a WILD guess. Collinite845 should run his up on the dyno and find out.

If I had one, Id do it and find out.

 

Just looked, Collinite845 doesnt own one yet.

 

I would assume 15%-20% drivetrain loss is pretty accurate.

 

Only way to settle this is to get someone to dyno their 550! That will settle it once and for all!

Has probably been done before many times! Maybe someone will post some "accurate" info for us.

 

Well, PAP, here you go: http://www.evo.co.uk/carreviews/evolongtermtests/60696/ferrari_550.html

394.5 at the wheels, 482bhp at the flywheel, 18.2% loss.

Next patient please!


Onno

 

EXCELLENT!!

Thanks mate. That settles it.

Dyno Dynamics dyno used there. Dyno's will vary, but as mentioned the 15%-20% must be the average.

My friend has never dynoed a 550, only my 348. His/my average of 33% drivetrain loss comes from all the front engine/RWD cars he has dynoed over the last 6 years. This goes to show how efficient the 550 drivetrain is!

An average 10% better than *most* cars.

 

My stock '01 550 dynoed at 410.0 rwhp and 361.4 rwt on a Dynojet chassis dyno. This was SAE corrected, but I've heard from others that this particular dyno is slightly optimistic!

Paul

 

Eddy current dynos like the factory pro, are typically 10% lower than a dynojet. But it's technically more accurate. Dynojet has more error in their technology.

 

Our regional Fclub has a "Dyno Day" event every year and the best numbers I've ever seen for a 550 was 409HP at the tires.

Drivetrain loss is around 15-20%, according to the dyno shop owner.

Couple years ago a friend's F40 pulled 490HP! Needless to say, he was running a LOT more boost than stock.

The next event is in March and I'll run my 550 to see how it does. It's stock, except for BMC filters, Hughes X-pipe and Tubi rear canisters.

 

We had our annual Northwest Region FCA Dyno Day yesterday and here's my test results sheet.

2000 550 Maranello w/BMC air filters, Tubi rear muffers and a Hughes silenced X-pipe.

418.41 HP, 367.12 torque

I was very pleased with the results.

PS: Check out the power spike around 6,800 rpm. The dyno guy thought it must be
something in the intake system that opens/changes settings. Anyone know what
it might be?

PPS: The dyno was just installed in 2007. Here's the info on it:

Dynojet Model 424xLC2 which utilizes a pair of 224xLC's along with an ingenious wheelbase adjustment system, the Model 424xLC2 can handle all the popular AWD vehicles on the road today. Along with offering the precise control from the eddy current load absorption units, the system also eliminates any potential speed bias between the two drums. This virtue is critical on some of the latest computer controlled AWD systems found in new cars today.
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I guess the spike is where the butterflies switch from the long (lower rpm) to the short (high rpm) inlet ports

 

Yep- I just found this info online:

Intake System
Ferrari developed a particular type of variable geometry intake manifold for the 550 Maranello engine to enhance torque and power features. The system, patented by Ferrari, includes a third volume added to the intake manifold, which changes its resonant characteristics. This additional volume is connected to the manifold by 12 throttle valves with electropneumatic servo control mechanisms, driven by the engine management control units. The additional volume is closed at engine speeds lower than 6000 rev/min, so that the cylinder can breathe through long primary runners favoring the mid-speed torque; at speeds higher than 6000 rev/min, the throttle valves are open. This translates into an optimized engine performance across the complete speed range. Additionally, the intake system is characterized by 2 quarter-wave pipes (one for each bank) upstream of the 2 airboxes. These resonators were tuned in order to reduce the overall intake noise level.

 

33% is WILDLY out of line for a halfway decent car... Using that number probably make the car owner happy though because now they are going to run around claiming an extra 15% HP over stock, but when they actually go RUN the car they are going to be sorely disappointed.

Standard transmissions loose much less than an automatic and 15-18% is kind of the rule of thumb on for a standard on a DynoJet and 18-22% would be expected with an automatic on the same dyno...

YMMV. Sure is fun to listen to a car at full chat on a dyno...LOVE IT! My S4 sang a beautiful song last year...WOW! Pulled 267HP/266Tq at the wheels. I was not disappointed with that. Auto trans 5.0L rated at 316/317... A little mixture tuning and it would probably be bumping 300 (I have seen some earlier 5.0L 928's pull those # so it should be possible with my car too). I can't wait to get an F-car and run that...never seen one on the rollers!

James

 

not to hijack the thread, but...well I'll hijack it anyway: as long as we're on topic, has anyone dyno'd their 575? I notice a huge surge in power at around 4500 rpm, which I don't remember having in my (previous car) 550. Anyone have a similar experience?

 

When does the exhaust dashpot kick in too? That culd have an effect. IIRC it came in lower like 5000rpm but maybe was not full open until 6800.

 

FBB- The pneumatic valve in the exhaust system is controlled by vacuum and is thus more driven by throttle setting than rpm. That said, they seem to be fully open, based on exhaust noise, at ~3000-4000 rpm depending on how much throttle is being used.

Taz
Terry Phillips

 

33% may be the loss for an automatic, but if it is for a manual, then there is a problem in that manual !!

 

Found this online about the 550 exhaust:

Particular attention went into the design of the exhaust system, resulting in a system with variable back pressure (similar to that on the F 50), and by-pass valves situated on the rear silencers. The by-pass valves are activated by an electropneumatic servo governed by the engine management system, on the basis of engine speed and throttle valve.

 

Gary- I read that, too. If you look at the diagram here, you can see that the accumulator's vacuum is controlled by a solenoid valve, which must be connected to the Motronic ECU. So it probably does use a combination of revs and throttle position to open the valves. There is most likely a simple 2D mapping of rpm vs throttle position to determine when to open the valves. Solenoids are simple full-on, full-off devices, so when the combination of revs and throttle setting reach a point on the map's line, the solenoid pops the throttle valves full open, and when it drops below the map line, they fully close.

The rev range I noted of 3000-4000 rpm still seems to work for hard to medium accelaration. Would be interesting to try a light throttle setting and higher revs and see if they stay closed until a higher rpm.

Taz
Terry Phillips
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great schematic. Where did you find it?

 

That's the parts manual.

A good source for for technical information is the workshop manual.
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