Jump to content

dwightlooi

Members
  • Content Count

    1,796
  • Joined

  • Last visited

  • Days Won

    3

dwightlooi last won the day on March 22

dwightlooi had the most liked content!

Community Reputation

468 #winning

About dwightlooi

  • Rank
    OSV Member
  • Birthday 09/10/1973

Contact Methods

  • Website URL
    http://

Profile Information

  • Gender
    Male
  • Location
    Belmont, CA
  • Interests
    Cars, guns, technology, design, politics, cooking, etc.

Recent Profile Visitors

10,754 profile views
  1. (1) Hybridization and the type of fuel the ICE burns are completely separate issues. If you can have a gasoline-electric hybrid, you can also have a diesel-electric hybrid. All else being equal, a diesel-electric design will be significantly more efficient than a gasoline electric drive train simply because the ICE component is more efficient (~40% thermal efficiency vs ~30%). (2) I do not believe that the world is moving towards electric vehicles as much, or as quickly, as the "Green New Deal" coolaid drinkers will like to believe. I say this because of four irrefutable facts:- The cost of an EV battery pack sufficient for a 200+ mile range (~80kWh) will buy ~12 years worth of gasoline at $3 a gallon if you drive 12,500 miles a year in a 30 mpg car. This is beyond the expected service life of the battery pack. In otherwords, even if electricity is free (it is not) you will never save a dime driving an electric car. Batteries, unlike combustible fuel, cannot be replenished in 3 minutes at a gas station. No truck driver wants to stop for 4 to 12 hours to recharge. The current electric grid and generation capacity is not ready for a transition to a primarily electric motor transport system. Battery disposal will be a problem because it contains rather toxic substances. (3) The impetus to eliminate, or significantly reduce, carbon dioxide emissions is based on the junk science of "Man Made Climate Change" which is increasing indefensible even if there is tremendous political and ideological pressure to keep the hogwash going. Like the 70s impending ice age hoax, the "Global Warming" nonsense will eventually fall apart. The economics of energy production not bull$h! will ultimately drive the energy choices of mankind.
  2. The Killed-In-Action Stinger is heavy as a rock and slow as a rock... LOL!
  3. Let's just say Mercedes, BMW, Audi and Lexus have 99% of the market share of the top 1%. To be in the top 1% you need to be making $421K a year in family income -- which is really not that much. That is about what you need to make to buy a home in California and still have money for a car... with a 1200 sq-ft 50 year old single family home in a middle income neighborhood pushing $1.7 million and taxes pushing 40% (State/Fed combined)... LOL!
  4. LOL... The first Rolex Daytona is basically a Zenith movement. Also, a well regulated ETA-2892-A2 will perform as well as any Rolex 3100-series and was used in everything from IWCs to Omegas to Breguets to a gazillion independents. Rolex doesn't even really "finish" their movements since they don't use glass backs and didn't think it matters. The only reason so many "high end" makers do their own movements these days is because Swatch Group is refusing to sell them their ETA movements. In house movements are more expensive but they are frequently less reliable and less accurate than proven, mass produced, calibers from ETA. For in-house movements to actually be better you'll need to be spending 20K or more. Anyway, that's besides the point. The point is that irrespective of any of that, BRANDS and the PRESTIGE AND STATUS associated with them MATTERS A LOT. That is true of all tertiary goods including but not limited to cars. Realists understand that and pay for that.
  5. You can call them that, but I will call them "STATUS REALISTS". The same kind of people who buy a Rolex never mind that watches costing 1/10th as much often have as good a movement or finish. They are realists because (1) a Rolex is recognizable by everyone and that is half the reason to spend $10K on a stainless steel watch, and (2) a Rolex actually GOES UP IN VALUE year after year. They are the same kind of realists who will buy a home with a hole in the roof and mold in the walls BECAUSE OF THE ZIP CODE. It is you who is arrogant and ignorant when you think that people do not, or should not, buy a car (or anything) based on the prestige and status its badge confers.
  6. Well, Mercedes has a lot more brand kudos and image than Volkswagen, Most people will pay $6K more to have a Mercedes over a Volkswagen even if both cars have identical performance, equipment and quality. That's reality.
  7. That is more of a cam profile issue than a valve train layout issue. To get high rpm breathing, it is necessary to have high lift and long duration cam grinds. These will have poor aspiration and low intake velocities at lower rpms, and hence reduced low end torque and probably lower peak torque as well. To have high tumble or swirl from high intake velocities, and minimal overlap induced back flow, loss of effective compression or early loss of the power stroke you MUST use a short duration cam grind with low lifts. The means toqur will fall off at high rpms and the engine wont make much power. Unless you have a camswitching system or a variable lift system, you can have one or the other or a compromise between the two,, but you cannot have both. Even with switching, there will be a step jump in the engine character when the switching occurs. This is true of pushrod engines and it is true of DOHC 4-valve/5-valve engines. The laughable thing which most people don't get is that 2-valves per cylinder is fully capable of supporting the airflow requirements for a power peak at or around 6000 rpm. Any engine that makes its maximum horsepower at or around 6000 rpm -- which includes most Toyota and Honda DOHC engines -- do not their DOHC valve train and do not benefit from the added friction, complexity and cost associated with them. For a DOHC 4-valve cylinder head to serve a useful purpose, the engine must make its peak power at or above about 7000 rpm. Then, and only then, do you need or benefit from the freer flowing DOHC heads.
  8. The Pentastar is more refined than the LF1, LLT or LFX engines because Pentastars are NOT Direct Injected. It's as simple as that. Direct injection is the biggest step backwards in engine refinement in the last several deecades until the advent of the Start-Stop nonsense.
  9. What GM needs is a "high output" version of the 2.7T 4-cylinder. A simple G25-550, or like sized turbo, with air-to-water intercooling will effortlessly make 420 hp @ ~ 5300 rpm and 420 lb-ft @ ~2200 to ~5200 rpm. That, for all intents and purposes, is enough. Boost levels will be no higher than on the LTG. Compression will be in the 9.0~9.5:1 range. It'll be perfect for the CT4-V, the Camaro or any of the crossover V or SS trim cars. If you don't mind some extra lag (like you'll find on the AMG M133 2.0T engine) you can easily make about 480 hp @ ~5500 rpm and 500 lb-ft @ ~3500 rpm. Same turbo and CR, but more boost. We are not even straddling the line here... the turbo itself is capable of supporting about 550 hp with low enough compression and if you don't care about linearity.
  10. All right gays, let me put it simply for you all:- (1) An engine being turbocharged (or not) has nothing to do with whether it is, or can be, high revving. Period. (2) Contemporary Turbocharged engines are typically not high revving because of the designers' desire to minimize lag and maximize torque down to the lowest reaches of the rev range. (3) Turbochargers generally have a range of airflow within which it functions well. A big turbo supports higher flow -- which means higher boost or higher engine rpms. A small turbo takes less exhaust energy to drive -- which means higher output at lower rpms and less turbo lag. (4) To be more specific, at about 20 psi of boost (~1.36 bar), the most advanced turbos can support a torque plateau of about 3000 rpm. That is to say you can have your peak torque of about 150 lb-ft/liter across about 3,000 rpm of engine speed range. This can be 1,500~4,500 rpm or it can be 4,000~7,000 rpm depending on the size of the turbo. Obviously, an engine the latter will make more power... much more power (greater than 200 hp / liter) and rev to 8,000 rpm without running out of breath. But expect 1990s style lag and rubberband like throttle response. With the former you get ~ 130~140 hp / liter, but the engine isn't dead between idle and about 3800 rpm. You can have either or something in between, but you can;t have both.
  11. For having NOTHING to contribute, you sure made a very long post! LOL!!!
  12. That takes at most 2 rotations of the crankshaft. At cruise with the engine turning at 2000 rpm, that takes 2/2000 * 60 = 0.06 seconds.
  13. Because NA engines get from 0 to, let's say 60% torque, at part throttle in about 0.1 second. The delay is from the intake manifold and runners downstream of the throttle body going from a greater to a lesser amount of vacuum as the throttle opens. With a turbocharged engine, everything that happens in an NA engine also happens. But that only gets you to the part throttle torque output of an otherwise identical NA engine. Next, the exhaust energy from the increased air/fuel charge starts spinning the turbo up. This causes the compressor to start bringing the intake ahead of the throttle to a higher pressure than atmospheric pressure. This is cut down to a fraction of that pressure by the throttle and fed into the engine. A cycle of every greater charge density, increases in exhaust energy and even greater charge density occurs until it is arrested by the waste gate opening and bleeding part of the exhaust around the turbine. This process takes a while. At part throttle, it often takes about 3~5 seconds. Compared to 0.1 the second it takes on an NA engine that feels like eternity. Also, it has a rubber band like effect where the throttle is constant and the engine rpm is not increasing much, but torque builds independently of rpm and throttle movement.

About us

CheersandGears.com - Founded 2001

We ♥ Cars

Get in touch

Follow us

Recent tweets

facebook

×
×
  • Create New...