I thought that DI was supposed to increase HP by a two digit percent, if so then it's not working. The new Passat has a 3.6l V6 engine with DI and a Compression Ratio of 12:1. 12:1 is very high and is aquired due to having DI but it's not reflected in the horse power numbers, only 280@6200RPMs. The 350Z makes 300 with a 3.5l @6400rpms with a 10.3:1 compression ratio, or the Maxima which is 265hp@5800RPMs. Why the huge difference?
Direct Injection?
- Thread starter mkillio
- Start date
WhiningKhan
Regular
I say 'bah' to normally aspirated 'performance' engines anyway. Why make a 3.6L engine? Equivalent power with better efficiency could be had with over a litre lower displacement in a turbocharged inline-4. Direct injection is just peanuts compared to that.
Damn those marketing strategies and all the people getting fooled by them. Just like the graphics cards manufacturers slapping huge amounts of RAM on value cards, so buyers think it's a good deal as it has the most memory you can get (while having a narrow memory bus, few pipelines etc.).
Damn those marketing strategies and all the people getting fooled by them. Just like the graphics cards manufacturers slapping huge amounts of RAM on value cards, so buyers think it's a good deal as it has the most memory you can get (while having a narrow memory bus, few pipelines etc.).
WhiningKhan said:
It's not as easy as you think. Smaller supercharged engines are an art in itself, because it's hard to make them durable in such a small package. Also, it's much harder to get high torque with the right distribution over rpm out of a small engine, regardless of HP. Also, the more you charge, the worse the exhaust values and consumption are, let alone noise levels and vibrations (deadly for sensors etc.).
Bigger engine = easier, cheaper implementation and better torque distribution, less vibrations in the desired spectrum the components are specified for.
If it was only about HP, we could still be driving engines we had 30 years ago.
WhiningKhan said:
Well... when I want to have(and paying through my nose to get it) a performance car, I want to be able to control it properly also. Turbos are nice HP-boosters and all, but they're shit to drive, quite frankly. A 2-liter 300hp(for instance) engine you'd have to boost to quite a bit of manifold overpressure -> major throttle lag. And as you up the boost, combustion chamber temperatures go up with it, and engine longevity down.
Blowers take care of most of the control problems, but then the efficiency arguments went out the window.
For me, the worst bit is not the above after all. It's that turbos sound crap. There's nothing more spinetingling than the sound of a finely tuned NA engine. BMW's straight sixes, Ferrari's V8's and V12's, I get goosebumps just thinking about it.
wtf?!
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What do you mean? Blowers as cooling fans or?
EDIT:
Sound-wise, non-supercharged engines are the best usually and also have the best dynamics. For pure power there's nothing better than compressors (roots loader). Easy to control, too - once it snaps, you reduce the torque to the desired max and have it almost over whole rpm range
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PC-Engine said:
Depends on the application. Race engines are tuned for power, while normal cars are tuned for balance between consumption, power and exhaust which makes them quite different.
The AMG V12 Biturbo with its 6.5l and 612 HP is one of the worlds best series engines, but sounds like crap on its own (there are other parts which can compensate the effect, sound wise and that's what's being done here as well).
mrdarko said:
I read the article about it in a car mag, but haven't seen a car with it yet. I'm really interested in that one, but it looks like it will be pretty expensive to produce. We'll see. An interesting concept, but I strongly believe that the (near) future belongs to hybrids, at least as long as the fuel cell or whatever may come out of that is not ready for the masses.
EDIT:
And I'd also like to see what this engine looks like after driving 200 000 km or so
_xxx_ said:OK, I assumed that. But it's called Roots loader or compressor, blower is the big fan in front of the engine.
Sorry for being nitpicky, I used to get corrected over that all the time before...
There are other non roots types that are very good.
WhiningKhan
Regular
_xxx_ said:
Well, Saab got it right already in 80's - if 200+ HP / 300+ Nm 2.0L / 2.3L engines are routinely driven 400000 kilometers in over 15 years even with the original turbo, I don't see durability as an issue if you want to do it right.
Also the torque issue rather the opposite - the torque curve is practically flat in turbos after the maximum torque has been reached, typically somewhere between 2000 and 3000 rpm's, whereas normally aspirated engines typically reach the maximum torque at much higher rpm's.
Vibrations indeed are worse in inline-4 compared to larger V-engines, that is true. And the turbo does have its lag, which in practical life means nothing unless you do traffic-light races with teens a lot...
. Some people don't like the turbo kick, some people do.I admit that I'm not one who would buy a 'performance' car anyway, pardon me for my dullness. I much rather have a practical, non-flashy car with power to overtake quickly when required.
How do you even change sparkplugs on that one?mrdarko said:
There's no room anywhere! Better hope it's a diesel then! Speaking of diesel:Two-stroke diesel would be cool to see in a car, instead of just giant trucks or ships... World's most efficient piston engine is a two-stroke diesel (that weighs around 220 tons or something rediculous like that, heh).
How about you murricans work on your liters per 100km instead?mkillio said:
mrdarko said:you're joking,right!
you should try living in england for awhile (or anyware in europe)
the last service on my 1.4 td cost £120 (~$200) for an oil and filter change plus
multipoint check!!
nevermind,if i get runover tommorow i won't have to pay to get fixed
Ouch! That really sucks and your gasoline prices are really high too.
Why do they charge so much for labor over there?
