BMW V10 and AMG 6.3

[GerFix]

Wrong - most pickups are NA. Oh, and there have been plenty of FI sports cars and supercars over the years.

 

[Eunos_Cosmo]

Eh...I dunno, it sounds kinda muffled, doesn't sound as raw or visceral doesn't evoke that sense of awe that the old V10 did.

I think you misinterpreted the meaning of his post.

I think there is a good bit more engineering in a high output, normally aspirated engine. For example, you must harmonically tune intake and exhaust systems so they have a peak range, and then correspond this range to camshaft selection. You have to create a very solid bottom end to take the revs. The valvetrain has to be extremely beefy. In a turbo engine, and I am simplifying this a bit, you just mount a turbo of the correct size (fair bit of engineering in this regard, to be fair) and make some good power. You lose any harmonic or resonance tuning in both the exhaust and intake because of the disruption and changes in airflow (going from vacuum to boost and back etc) The end result is something that doesn't feel so highly tuned, and just special.

N/A supercar = badass
Turbo supercar = nifty!

 

[chaos386]

you just mount a turbo of the correct size (fair bit of engineering in this regard, to be fair) and make some good power.

...and then you blow up your engine because you forgot about how forced induction affects the knock characteristics, didn't design a way to limit boost surges or spikes, completely forgot to change your cooling design, and didn't devise an engine management system that takes into account all the new operating variables you just introduced by tacking a variable-speed compressor onto the intake *and* exhaust.

 

[Eunos_Cosmo]

...and then you blow up your engine because you forgot about how forced induction affects the knock characteristics, didn't design a way to limit boost surges or spikes, completely forgot to change your cooling design, and didn't devise an engine management system that takes into account all the new operating variables you just introduced by tacking a variable-speed compressor onto the intake *and* exhaust.

I said I was simplifying...

Everything you listed is just things that must be done in preparation for a turbo, whereas my post was mainly focused on the mechanical tuning needed for making a high output engine. Yes there is a lot of fuel/ignition tuning that must be done for FI, but not much more than n/a.

 

[chaos386]

I said I was simplifying...

I know. I thought it was odd to say that N/A tuning was more complicated when you've purposefully left out the details about FI tuning. Now, I'll admit I'm no expert (which is probably why only fuel and ignition-related things came to mind), so I don't know what you mean by "mechanical" tuning. You still need to properly tune the intake and exhaust for an FI engine, and the compressors themselves are quite "mechanical."

 

[the Interceptor]

so I don't know what you mean by "mechanical" tuning.

changing camshafts, increasing bore and/or stroke, raising compression, changing components to withstand higher revs, etc. - classical, mechanical tuning.

 

[JCE]

What rubbish is this, engines having character?
It's the same as saying cars have souls, they don't!
http://www.thesmokingtire.com/2009/editorial-cars-have-no-soul-viewer-submission/

Now that is worthless garbage I just read. Can I have my few minutes back I wasted read it? :?

Just because there is an article to the contrary does not automatically make it a fact. This is compounded by the fact that it is a very subjective (even philosophical) issue. Cars DO have souls, at least in the capacity of the people who create them. That article says that every car is designed with good intentions so none can outweigh another in character. This is an extremely naive statement and it is akin to 'everyone has ambitions of being great, so everyone is equally great.' What separates the productive and successful from the weak isn't the ambition; it is the devotion, the passion, and the commitment. This is easily extrapolated to cars and their engineers. Yes you can easily say that the designers of the Dacia Sandero or some other similar car go into the design stage with the best intentions...but that isn't what matters. What matters is what comes out. What matters is how everything came together, because this is the most difficult step. A Ferrari will have infinitely more soul than some Daiwoo because there was nothing (or very little) stopping the souls of the engineers from coming through in the finished product. You obviously pay a price for it, but then you have to; you are purchasing a piece of absolute passion from a collection of some of the greatest engineers and designers in the world. Basically you are leasing their mind. Cars are endowed by their creator all of the character and soul of that creator. They do have soul.

As far as engines go, I prefer naturally aspirated engines but I don't think you could qualify the statement that they have more soul/character than their turbo brethren. They (to me) sound better, have a more exciting powerband, and generally produce a more thrilling drive. If excitement=character than I suppose you could make a case for it.

This sound cannot be replaced:

The world is far too sensible now.

+rep Excellent post. And kudos for pointing out the little statement that makes cars have soul. PEOPLE. My SVT Focus has soul, so did my 3000GT VR4 (god rest his soul). My Camaro, my 240SX, my 200SX and the list goes on. Each had it's own personality and behavior. I swear some of my cars even grinned at me when I walk up to them about to get in to drive. *I* feel and believe my cars have soul, so therefore they do. Even granny mobiles have soul--they are just old people souls that are boring and knocking on the pearly gates. :lol:

The X5 ///M sounds absolutely the same like my 750 (ok it's a bit louder) and I think that's missing the point. Because the ///M engine should sound special and not like every x50i.

This is a very good point. I want my M BMW to sound special and insane, not like any regular.

N/A vs charged... hmmm...

https://pic.armedcats.net/n/na/narf/2010/07/08/800px-Porsche-964.jpg

https://pic.armedcats.net/n/na/narf/2010/07/08/Porsche_964_Turbo.jpg

Which to choose


/thread :lol:

The NA 911 has just as much soul as the Turbo. However the type of souls are different. One will kill you the other will just put a smile on your face. :lol:

Back on topic, the 6.3 V8 is probably my favorite motor (SLR not withstanding) that's ever come out of Affalterbach.

+1.5 The Merc 6.2L V8 is probably my second favorite sounding engine ever after the Ford 4.6L 3V V8 found in the Mustang Mach 1 and SVT Cobra (I won't count the Navigator since it's not a sports car). Right out of the box with stock intake and exhaust (if you can call AMG intakes and exhausts stock) it sound like it could destroy the earth.

 

[narf]

The NA 911 has just as much soul as the Turbo. However the type of souls are different. One will kill you the other will just put a smile on your face. :lol:

Exactly my point. Both are good choices.

 

[Eunos_Cosmo]

I know. I thought it was odd to say that N/A tuning was more complicated when you've purposefully left out the details about FI tuning. Now, I'll admit I'm no expert (which is probably why only fuel and ignition-related things came to mind), so I don't know what you mean by "mechanical" tuning. You still need to properly tune the intake and exhaust for an FI engine, and the compressors themselves are quite "mechanical."

I'll just give an example of what I mean. The bone stock 13b in my car makes 138bhp from the factory. It is running through a fairly decent intake manifold, but the exhaust is terrible. Put a normal header on it and you will pick up 20hp or so. But there are a FEW exhaust systems out there that can make up to 100hp (combined with a tubular style intake manifold) more than stock on a 13b. How is this possible? Its called exhaust scavenging. This is going to get technical, so bear with me:

Whenever the exhaust valve opens after a combustion two things come out. Obviously the physical exhaust gases come out but in front of this, there is a pressure wave moving at the speed of sound. When that pressure wave reaches the end of an open pipe (usually the end of the header primary tube) it switches direction and becomes a vacuum moving back towards the exhaust port. Exhaust tuning is intensely focused on this pressure wave. The idea is to get this low pressure wave to hit the exhaust port right as the exhaust valve (or port in a rotary) opens. When you do this, the low pressure zone in the exhaust pipe literally sucks the exhaust out of the cylinder/rotor. This of course involves making header primaries of an EXACT length and diameter to time this sonic pressure wave as it comes back in forth. It is also possible to work in half lengths so that the effect will work on several different RPM ranges. This is the exhaust tuning. I watched an incredible high-speed video of an explosion inside of a plexiglass tube where you can see the gases slowly accelerate to the end of the tube while the pressure wave bounces back and forth at the speed of sound.

In addition to this, intake manifolds can be tuned in a similar matter. Engines like Honda's K20 vtech actually achieve volumetric efficiency of over 115% (bone stock!!) naturally aspirated. This means that the engine is actually pumping more air than the engine technically has the volume to contain, ie compressing the air just by harmonic tuning. Supercharging. To me, this is very brilliant engineering and the engine just feels way more special. That is a 2.0 making 200bhp, give or take. The RX8 has a 1.3 liter making 238hp, so the VE is even higher with the 13b-msp. Both of these resonance tuning affects are voided with the addition of a turbocharger. The turbine interrupts exhaust flow, and the compressor intake.

I own a Merkur XR4ti with a 2.3 sohc 4 cylinder with a turbocharger. It makes somewhere between 170-190hp. I also had a 1994 Honda Civic with a b16a making aorund 160-170bhp. Technically, the Merkur is faster (well it would be if they were the same weight) but the engines were simply not comparable. The b16a has lightning quick throttle response, an incredible induction noise, and the feel of the seemingly never-ending power band (it revved to 9,000rpm) was intoxicating. The Merkur, while I love it, has an uninspiring engine.

A highly tuned n/a engine is basically a hand crafted musical instrument, that is why I love them.
/nerd