Guilty

I'm just curious here... I read a lot on the forum that the M156 is the best V8 ever made... why do people say that?

The ferrari 458 has a N/A engine with 4.5L and it's far more powerful than the M156... What makes Ferrari so good at extracting so much power from a smaller engine?

Please excuse my ignorance, just trying to learn

Thanks!!

johnnyblaze

have you ever heard about the endless reliability problems with Ferrari's? Sure they are great drivers cars, but no one wants to daily drive them without the penalty of heavy repair costs.

Guilty

The 458 seems to have less problems than the other Ferrari's. That's what I read on the ferrari forum

johnnyblaze

Maybe. But that model has only been out since 2011. I doubt anyone has over 15k miles on it.

mainly

im sure someone with more knowledge can confirm this or not, but i BELIEVE the reason Ferrari produces the same power with a much smaller engine, has something to do with the fact that the Ferrari rev's to 9000 rpm, vs a Merc's 6XXX rpm.

if the Ferrari only rev'd to 6 or 7000, it would probably only make ~450 hp.

of course then it wouldn't be a Ferrari.

from 6000 rpm to 9000 rpm, the 458 makes like another 150 hp!!!


of course the sls has the same engine and it makes the same power as the 458; bigger engine, less rev's...

natman316

Its got to do with bore and stroke ratio. Ferrari has shorter stroke so it revs higher and gets more hp out of its displacement but the downside is that its lower on torque an doesnt make much power down low.

Kinda like how m3 makes nearly as much power as us but with way less displacement but it has less tq and has to rev like a Honda haha

Guilty

@natman, that explains why ferraris are super loud... the sound is intoxicating! I wouldn't mind the high revs if the car has that sound lol

Quadcammer

um, no it doesn't.

GBlansten

Minor correction but M156 redlines at 7200 rpms. I agree with your general point.

Swoody

Not really, that intoxicating sound comes from their "flat plane crankshaft".
The flat-plane or single-plane crankshaft has crank pins at 180°. They are imperfectly balanced and thus produce vibrations unless balance shafts are used, with a counter rotating pair flanking the crankshaft to counter second order vibration transverse to the crankshaft centerline. As it does not require counterweights, the crankshaft has less mass and thus inertia, allowing higher rpm and quicker acceleration. Flat-plane V8s on road cars come from Ferrari (every V8 model they ever made, from the 1973 308 GT4, to the new 458), Lotus (the Esprit V8), TVR (the Speed Eight) and McLaren (the MP4-12C). This design is popular in racing engines, the most famous example being the Cosworth DFV.[16]

The HP per liter is a function of it's direct fuel injection, compression ratio (12.5:1) & RPM...

otakki

Like the good old saying, hp sells cars but tq wins races. Of course that doesn't apply to everything but it's generally true. For everyday driving, tq is your friend.

ffx5201

No mention of the Chevy small block? jk.

I don't think that the "best" V8 should be based solely on most hp/liter or torque/liter. As Swoody mentioned, powered generated is influenced by compression ratio and RPM, but there are also other significant factors involved- the two most important to me is how much the manufacture wants to make the motor cost (which consequently translates to the vehicle's MSRP) and what the appropriate life span of the motor would be.

Guilty

Damn! You guys are so knowledgeable! Thanks for all the answers even though I need to work on my vocabulary and look up all the words I don't understand

emericr

I thought the M156 won for 2 years and then lost to the Ferrari engine. I am too lazy to google it and hope you guys will correct me.

shchow

I think you got it reversed.
The CROSS-PLANE engines are imperfectly balanced and need counterweights.
The SINGLE-PLANE engines are better balanced and do not need the extra weights and revs much more freely and has a very characteristic engine note.
The sacrifice in the single plane engines is probably durability...

Djovovic63

M156 really was/is considered as one of the best V8s ever made. However the first V8 engine to be considered as good or maybe even better then M156 was Ferrari's V8 458 engine.

Guilty

Hypothetically, what stops AMG for making our cars sound like a ferrari? The way the guys are explaining it here makes it sound so easy!

Merc63

Well my Dodge 3500 Diesel doesn't win many races unfortunately.

But I can squeal the tires off the line with a trailer and skid steer on the back of it.

TORQUE GETS U OFF THE LINE, HORSEPOWER WINS RACES.

gthal

Don't forget the S65 in the M3... it is also widely regarded as a fantastic engine and has won many awards. It would be a real debate as to which engine was better... the M156 or the S65.

The S65 and engine in the 458 develop a lot of power, as others have said, for their size as they have very high red lines. Power is a function of torque and RPM. If the M156 could rev to 9,000 RPM it would generate a sh$t load of HP!!

gthal

That's cause is has a REALLY low red line and doesn't freely rev (among other reasons like gearing, weight, etc). Like I said above, torque and HP and RPM are all related.

Merc63

I see diesel trucks running 10s at the track every weekend, they only rev to 3000rpm and dont rev freely.

Torque gets you off the line and HP wins the race.

gthal

I agree because HP is a function of RPM and torque. Big torque and low HP because low max RPM.

34.50

Don't know about you guys but I think Ferrari have a **** exhaust note. It just sounds like a high pitched whiny engine. I like the deep growl of the AMG, now that's an exhaust note

Higgs Boson

saying torque this and horsepower that means nothing. horsepower is a mathematically derived figure and is a function of torque. an engine doesn't even make horsepower, it makes torque. humans calculate horsepower, it is only torque spread over time (rpm).....

just the same as there is no such thing as time in the universe. it is only humans way of calculating distance and motion as a function of our lives. if there is no such thing as time, there is definitely no such thing as horsepower.....

besides, you can't look at hp and tq without including weight and gearing into the overall equation. a Ferrari motor would suck in a dump truck....

Vash

+1