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dwightlooi

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Everything posted by dwightlooi

  1. Here's an idea for Corvette's baby brother...
  2. FICTION Chevrolet Speed The Chevrolet Speed is built on the AMR (Affordable Mid-engine Rear-drive) Platform to be an affordable sibling to the Corvette that appeals to buyers in their 20s and 30s. It is designed around the 3-3-3 paradigm calling for a 300 hp car, weighing 3,000 lbs and costing 30,000 dollars. The modestly sized car features an architecture that avoids using expensive materials such as aluminum, magnesium or carbon composites, while utilizing an all-strut suspension design. Power is provided by a 2.7L turbocharged Inline-4 from the Silverado Pickup and the high torque rating dual-clutch transaxle is sourced from Getrag. The entire powertrain and its cooling system are contained in the engine compartment behind the occupants with the radiator positioned horizontally above and behind the engine, while side scoops feed air into the compartment. There is a 6.6 cu-ft trunk under the engine compartment cover but no front storage compartment with electric HVAC and steering taking up the space under the hood. The cabin is an exercise in spartan simplicity with no instrument cluster, buttons or knobs; just a Heads-Up-Display and a 12” LCD multi-function touch screen in the center console. Seat adjustments are manual and a simple 5-speaker BOSE stereo system rounds out the amenities. A Premium Performance Package adds a 360° camera system, leather upholstery, 18” wheels, Magnetic Ride Control and a helical limited slip differential for $6,000. A 420 hp Chevrolet Speed SS is expected to follow featuring a 420 hp version of the 2.7L engine, air-to-water intercooling, bigger brakes and Michelin Pilot Sport 4S tires. FICTION
  3. We don't know that, and we'll NEVER know that. Even if it is true the ChiComs will never admit it because everyone in the world and their own population will be lining up to pound them in the arse. Sure, the Chicom will survive such a scandal, but Xi Jinping is not invulnerable -- not to other aspiring power blocks within the Chicom at least. So, you'll never know because there is no way they'll let you.
  4. Dead divided by dead plus recovered. You do not count people who are still sick because some of them will die but haven't died yet. 2876 / (2876 + 36873) = 0.072354 I also believe that the death rate will go up when you have millions of people sick because when the medical care the you get is an asprin, a bottle of water and a cot in a converted stadium you are more likely to die than if you have 10 nurses, 5 doctors and a specialist from the CDC to fussy over your daily progress like you do now, with a respirator, an ECMO machine and all the gadgets of a good ICU at their disposal if you need it. Sick?
  5. 2.5% is utter rubbish. It will be much higher, probably around 10~15%. You need to compare the death rate to the recovery rate, not the total infected. Not even taking into account under reporting by China for economic reasons, we have:- 84,144 infected (total) 39,749 have concluded their illness (recovered or died) 2,876 dead 36,873 recovered Death ratio 7.2% If and when you have millions infected, you are not going to have a hospital bed and intensive care for people who need it. 36,308 currently sick 8,087 in serious or critical condition Serious illness ratio is 18.2% Without ample medicare care, more than half -- probably closer to three quarters -- of 18.2% who become seriously ill will die. If there is no no vaccine and no effective anti-viral treatment (which I am optimistic there will be), we can expect about half the world population infected at some point and that 10% of those infected will die. This is disease has the potential to kill 390 million people or about 5 times more than WWII.
  6. What I was trying to point out was that downsizing to 1.4L and packing a turbo to get in the same power bracket as a 2.0L NA engine does not actually yield ANY fuel economy advantage. I bet you that a 2-valve Inline-4 displacing 2.7 liters but running an Atkinson Cycle cam will deliver the same 150~160 hp with better fuel economy and emissions than ANY 2.0L 4-valve engine or 1.4L turbo. It'll be a bigger engine but it may not necessarily be heavier given that it ditches the big fat DOHC head. Actually, more valves = worse emissions. Remember the 3.2L and 5.5L 3-valve engines from MB about 15 years ago? The reason they went to 3-valves is to reduce the exhaust valve surface area. Less area = less heat loss through conduction during cold starts and quicker catalyst light off. More valves also mean lower intake velocity and poorer mixing at low engine speeds. You can mitigate that with variable tumbler vanes (VW-Audi) or you can simply reduce valve lift or deactivate one valve (Honda) on a DOHC setup. But, the need for such solutions only goes to show that storm drains are not always the best when it comes to intake ports and valves.
  7. If that is your objective, the 4.2L Blackwing or 3.6L HF V6 still makes ZERO sense. They are not exactly "low displacement". If that is your objective, have a pair of engines specifically for those countries with displacement taxes. Like say a 0.99L I4 boosted to 160hp and 1.99L V6 boosted to 320 hp or something along those lines. And don't worry about lag either because these also use the same 48V electrics and that 50 lb-ft @ 0 rpm motor-generator helps plenty with response from 0 to 4000 rpm -- not so much to move the car but to move the engine revs to the sweet spot during a downshift for the turbos to work when you floor it. The way DC motors work is that if you start at 50 lb-ft and are down to 0 lb-ft @ 6000 rpm, you are still making 25 lb-ft @ 3000 rpm. We are not even talking about a Prius level hybrid here. No planetary gear set. Just a Iron Phoshate battery twice the size of the 12V battery you are used to and a motor that is mainly a starter and alternator. If you are wondering why 48v? It's because it is perfect for a 50~75 lb-ft motor. Running that off 12V or 24v will mean VERY THICK cables and high amperage. You don't really need the 200+ volt electrics until you get to serious drive motors in the 150 hp class with 200~300 lb-ft. It is also exactly 15 x 3.2v Iron Phosphate cells in a series. 15 is not that much more than the stack of 10 you find in a lead acid battery to get to 12v. This keeps the battery simple and cheap.
  8. Look, if it is profitable it is TAXABLE. If it is breaking even or losing money, it is not. It is very easy to make a division lose money -- just make it do a ton of R&D and prototyping which soaks up all the profits and then some. Now, once developed, the technology is then "shared" or gifted to the rest of the company. NOT ROCKET SCIENCE. This is why high corporate taxes is pointless in the era of multinational corporations. Where do you think they take their loses and where do you think they move the profits? If you guess high tax countries and low tax countries, maybe you are not retarded afterall!
  9. Not really. Down sizing is in theory for fuel efficiency. And, fuel efficiency might be an emissions thing, but no emissions standard anywhere actually cares about how many valves you have. Down sizing however hasn't proven to be all that beneficial to fuel economy. The 495hp 2020 Corvette at 3,700 lbs with 6.2 liters of pushrod power gets 15/27 mpg (it would have been higher too if not for the very short gearing to get the car to 60 mph in 2.9 secs). The C63 AMG with its 469hp 4.0TT at 3,800 lbs gets 18/27 mpg from 2/3rds the displacement. Doesn't seem like all those cams and losing 35% of the displacement helped very much. This is true not just of high power performance engines. A Chevy Cruze with it's 1.4L turbo gets 153hp and 28/38 mpg. A Toyota Corolla with a 42% high displacement 2.0L engine with turbos get 169hp and 31/40 mpg. So, it seems that the minimize displacement while maximizing specific strategy doesn't seem to pan out.
  10. Actually, they never did -- to their own detriment. The point really isn't "high powered" V8s. The point is to ask yourself what power you need for a given application and how to most economically, reliably and efficiently produce it. At 400, 300 and 200 hp naturally aspirated, the 5.3L V8 4.0L V6and 2.7L I4 fits into the applications perfectly. A 600 hp bi-turbo is also ideal for flagship luxury cars and SUVs. You can make all that with a smaller architecture than already very small and compact small block. The problem with DOHC designs is that there is practically NO ADVANTAGE to them. You do not need the additional flow capabilities of 4-valves per cylinder at 6000 rpm and you don't want a 9,000 rpm engine in a Malibu or Escalade. So, essentially you are paying 4 times as many camshafts, twice as many valves and lifters, more internal friction, more things to break, more things to cost more money, much heavier and bulkier heads, all for what? ABSOLUTELY no benefit. Look... I drive an Audi with the 4.0T. I know all about its overly complicated 4.0L hot vee engine with buried oil screens, cracking PCV system, vibrating downpipes, exploding turbos and the 435 hp / 445 lb-ft it makes. Yeah, that's LS1 territory at 25% more engine mass. I get 16-18 mpg out of it in daily driving so, no it is not really more efficient -- in part because V4 mode basically do not kick in much except when you are steady at 65 on cruise control with no gradient because 2.0L off boost really isn't much. BTW, this engine only revs to 6000 rpm (5,400 when cold) so what is the point of DOHC 4-valves when we know that pushrod 2-valves flows enough air for 80 hp/L at power peaks up to 6450 rpm (LT2)?
  11. Let me just say this... the Blackwing V8 is probably dead given that the new 2020 Escalade DID NOT USE IT. And, good riddance. GM should focus on their strengths not try to copy the Europeans overly complicated and unrelaible engineering paradigms when it is 20 years too late and buyers committed to European engineering hype are not going to give Cadillac a second look anyway. Here's what I believe GM should do for the 2020s... say hi to the.... Microblock Family The Microblock is a pushrod 2-valve per cylinder architecture scaled down from the Smallblock design. Bore spacing is reduced from 111.76 mm (4.4") to 101.6 mm (4.0") allowing the engine to be 40 mm shorter, narrower and lighter than the Smallblock. With the new V8 tipping the scales at very svelte 180kg, the Microblock offers 8 cylinders with a mass comparable to turbocharged DOHC V6 engines. A bore of 93mm and stroke of 98mm gives a displacement of 5,326 cc (325 cu-in) in the V8 engine with 11:1 compression enabling the use of 87 octane fuel. More importantly, the same dimensions give an ideal 3,994cc (244 cu-in) displacement to the V6 and 2,663 cc (162 cu-in) in the the Inline-4. Despite the longer stroke, piston speeds at the engines' 6,000 rpm redline is actually 3.2% lower to the Smallblock 6.2L engine at its 6,600 rpm rev limit giving improved harmonic refinement. The V8 and V6 engines feature Dynamic Skip Fire technology, while all engines adopt GM's new 48v electrical system. This new arrangement ditches the starter and alternator in favor of a flywheel integrated motor-generator with 50 lb-ft @ 0 rpm and 15 hp @ 3,200 rpm, while featuring a trunk mounted Iron Phosphate battery with a 20-year/200,000 mile maintenance free service life. Also eliminated is the accessory belt and the mechanically driven water pump allowing the engine to match the electrical system's 20-year/200,000 mile scheduled maintenance interval (apart from annual 20,000 mile oil changes, filter replacement and fluid monitoring). The family is introduced with four engines a 600 hp bi-turbo version available exclusively on Cadillac vehicles as their premium power plant, a 400 hp V8, 300 hp V6 and 200 hp I4. 5.3L Microblock V8 Bi-turbo (LVT) -- 600 bhp @ 5,300 rpm, 600 lb-ft @ 1,600~5,200 rpm, 6,000 rpm redline (91 octane) 5.3L Microblock V8 (LVE) -- 400 bhp @ 5,800 rpm, 400 lb-ft @ 4,200 rpm, 6,000 rpm redline (87 octane) 4.0L Microblock V6 (LVS) -- 300 bhp @ 5,800 rpm, 300 lb-ft @ 4,200 rpm, 6,000 rpm redline (87 octane) 2.7L Microblock I4 (LVF) -- 200 bhp @ 5,800 rpm, 200 lb-ft @ 4,200 rpm, 6,000 rpm redline (87 octane) Why? Because pushrods are nothing to be ashamed of. They are in fact superior for the rpm range which street cars motors operate in.
  12. Cars gave way to TALLER Cute Utilities and Crossovers, so the TRUCK drivers need a boost to stay above the fray.
  13. I have ALWAYS said that Direct Injection is the biggest step backwards in refinement in piston engines in the last 50 years. It is a sure way to get the diesel clatter even when its not a diesel engine because you are opening and shutting injectors against thousands of psi in fuel pressure not tens. If your 1st priority is refinement you will not use DI -- that is why Lexus uses port injection at idle and at low engine rpms or loads, switching to DI only when load picks up or at high rpms where the noise is insignificant with all the other noisy stuff going on. It is also not a matter if but when carbon clogs your intake port if you have DI. This can be as bad as within 2~3 years on the early VW-Audi FSI nightmares are about 10~15 year on the average late model DI engines. Why? Because you will have a tiny bit of blow by, some small amount of overlap EGR and vapors from your PCV. All of these are sources of carbon compounds in the intake tract. With ZERO fuel and its detergent to clean it off, it will build up over time. The only way to clean it is disassembling the bloody thing and using a walnut blaster or elbow grease to scrub it off. With DI you ALWAYS have two fuel pumps. One in the tank to move fuel to the engine. One on the engine to raise the fuel rail pressure to four digits in psi. This high pressure pump and the high pressure injectors fail in a dozen years when the gentle port injection stuff runs for 30 years. All of that for what? About 0.8:1 more compression and hence 2~3% better energy recovery. That is not even 1 mpg in a 30 mpg car. No, it's not really worth it, but it is the current fad just like bullsh!t Start/Stop systems.
  14. If you have four journals and 5 mains it can be even fire. But it won't really be a V8 chopped in half and no it is not balanced. Neither is a 90 deg V6 like the 3800 or the VW-Audi longitudinal engines like the 3.0T (supercharged) BTW. They have a balance shaft.
  15. LOL... have you ridden a Harley? If you don't mind the shake it's great! Anyway, the point is that with two journals and a 90 degree block, your firing sequence will be at best 0°--90°--360°--450° instead of 0°--180°--360°--540°. It'll be boom-boom........boom-boom........boom-boom......boom-boom. Like a Harley evolution twin (well that is worse because it is a 45 degree engine, but you get the idea). If you try to turbo or supercharge something like that you have another problem. Think of a turbo or supercharger as an air pump. The amount of boost that builds depends on how much air is being forced per unit time into the manifold and how long the intake valves are closed so the air has nowhere to go. When the valves open the engine ingests this built up charge of air, hence "boost". Now imagine that the valves open once after 90 units of time then again after 270 units then 90, then 270, etc. What that means is that your "pump" has three times as much time to build up the charge for two of the cylinders vs the other two. If two cylinders are experiencing 10 psi, the other two will see 30 psi. What are you going to do? Have different compression ratios and fueling for half of the cylinders? Now that is a complete $h! show.
  16. You can't really do that. Balance and packaging aside, if you keep the V8's architecture with regards to the main bearings and bank offset you end up with a V4 that has three main bearings, two journals and two rods sharing a single journal. There is no way to make that even fire. It'll sound and shake like a Harley V-Twin. You cannot turbo or supercharge it -- because the intake events are not evenly space, hence two cylinders will get more "boost" than the other two. It'll be a mess. For a V4 to "work" it must have four journals and five mains. This will mean abandoning the 90 deg V8's architecture and starting afresh which defeats the purpose. A more practical thing will be a Pushrod I4 which shares the V8's design and parts. It'll be a very beefy one at 3.1 liters, but it's not like that hasn't been dine before. Look into the Porsche 968 Inline-4 engine. That's a 3.0 liter SOHC 8-vavle design. It's not pushrod operated, but it is 3 liters and it is 2-valves per cylinder. The bore is 104 with a stroke of 88, which is similar to the LT2's 103.25 x 92. It made 237 hp @ 6,200 rpm with 225 lb-ft @ 4,100 rpm. Again, very close to GM small block specific output and rev range.
  17. I think it is time for GM to abandon the DOHC V8 and V6 engines while going back to reliable and efficient push-rod designs based on the LT2. Let's call it the 6th Generation Small Block V8 and V6 engines. Universally, they should have these features:- 103.25mm (bore) x 92mm (stroke) Dual Injection (Direct and Port) Synchronous continuous VVT (0~6 or 0~8 cylinders operation) Dynamic Skip Fire Flywheel Integrated Generator-Starter + 102v LiFePO4 electrical system 6200 V8TT (LTA) -- 600 bhp @ 5,300 rpm, 600 lb-ft @ 1,200 rpm, 6,000 rpm rev limit 6200 V8 (LTX) -- 480 bhp @ 6,200 rpm, 470 lb-ft @ 4,800 rpm, 6,600 rpm rev limit 4100 V6 (LTS) -- 360 bhp @ 6,200 rpm, 352 lb-ft @ 4,800 rpm, 6,600 rpm rev limit An interesting way to handle Start-Stop is that with a powerful enough motor integrated into the flywheel, there is no need to restart the engine on brake release. Instead, 0-600 rpm is always on electric power exclusively unless the battery is below 20% charge. The ICE starts naturally and takes over from there. A 102v LiFePO4 battery with about 0.6 kWh should be enough and it is about the size of two lead acid car batteries so it won't be too inconvenient to place them under the trunk or in the engine bay. A linear motor operating on 102v power can be realistically around to 30hp @ 3,300 rpm and 96 lb-ft @ 0 rpm.
  18. The Audi 3.0TFSI has a similar whine (S4, SQ5, A8 3.0TFSI, etc). Well, it has the same Eaton TVS 4-lobe supercharger (albeit a shorter version TVS R1320 version rather than the LT4's R1740 or LT5's R2300). That is also Audi's most reliable engine in the current lineup. It is new enough to not have the 1st gen FSI's Direct Injection intake fouling issues and it does not have the grenading turbo problems of all the VW-Audi engines with a check valve and oil screen in the turbo oil feed. FYI, if you own a car with the Supercharged 3.0T (not the newer Hot-Vee single turbo 3.0T), the TVS R1320 makes about 33% more boost than the 3.0T engine actually uses. So the ECU cracks the bypass valve at higher rpms to bleed off boost it doesn't want. This overboost and bleed concept is also used on the Jaguar AJ133 and other supercharged engines. It means that if you screw with the ECU program and keep that bypass valve shut longer and open it less, you get quite a bit more power... about 100 hp and 90 ft-lbs more over the upper half of the rev range.
  19. The car is 4 years old with 40K miles. It is covered by the CPO warranty for 12 months / unlimited miles and the turbos are covered by the 7yr/70K miles emissions warranty. I have a year to decide if I want to buy extended warranty. Powertrain Warranty from Audi is $2800 for three additional years past the CPO. Doing the preventative filter change is $2000. The thing is that if you ever intend to retune the ECU, buying warranty is a waste of money because any flash of the ECU will increment a HW flash counter. Any undocumented variation on the flash counter from VW-Audi records will flag the car as TD1 and void your warranty.
  20. The Germans have their fair share of TOTALLY RETARDED engineering. The CEU engines (aka Audi 4.0T V8) has a pair of "oil screens" in the turbo oil feed lines to keep the oil supply to the Hot-Vee mounted turbos "cleaner". Oil screens are by definition a filtration device and a service item. But, they bury them under the turbos, intercooler and intake assembly in a totally un-serviceable location. In the RS6 and RS7 cars it's 10 hours of labor to get to them because the front bumper has to come off. In the A8/S8 about 6 hours because the W12 accommodating engine bay is a tad longer so the intercooler can be removed with the bumper in place. The Audi service manual and scheduled maintenance does not include replacing these screens. So over time they clog and cut of oil to the turbos. The turbos then grenade themselves. If you are lucky it's just the turbos and a $13,000 repair at the dealer. If you are not, the metal fragments totals the cylinder walls and it's $45,000 for a new engine. About a fifth of the cars grenade their turbos between 40 and 80K miles. That is terrible. Preventative maintenance on this known issue is to replace the screens. But it's $2K and 6~7 hours of labor for an oil change if you do that. LOL! Good thing the car has a 7/70K warranty on the turbos and the emissions equipment.
  21. The LS9 has been out of production for years. There is the LT5 though. I'll say that 755 bhp / 715 lb-ft is "adequate" big and heavy SUV or not. It's a Dual Injection engine too. So if Caddy wants it can idle and putter along the parking lot with port injection to eliminate the DI clatter. It'll also keep the intake valves clean of carbon. And, if you care it is also hand built by one technician from start to finish in the same plant as the Blackwing.
  22. Agreed. My point is that an engine does not need to be a 4.2L DOHC Hot-Vee V8 to be "hand-built" -- you can do that with any design -- and that the Hot-Vee configuration does not require or necessarily include higher tolerances. I just got a car with a Hot Vee V8 -- the Audi CEUA 4.0TFSI bi-turbo engine. I have no problems with it (yet) but a Pushrod V8 would have been a simpler design with equivalent performance and less potential issues. A Pushrod V8 of 6 liter class displacement will also be able to spend more time in cylinder deactivation mode than the 4.0 liter mill. This is actually one of the reasons why they did not go to 5.5 liters with the C7. They could have and that engine would a have made about the same power at higher revs. But, fuel economy is actually worse because the AFM operating regime was narrower.
  23. Moral of the story? Capitalism rewards handsomely those who dramatically change how we live our lives for the better -- be it Ford then, Gates, Jobs, Bezos or Suck-a-Bird more recently. That is a good thing because there is nothing like income equality when it comes to ensuring that nothing gets invented, no sht gets done and everyone is a useless dependent of State.
  24. The 3800 was a fantastic engine -- smooth, reliable, bulletproof and economical. The 3.6 DOHC HF V6 -- at least for the first two generations from LY7 to LLT -- not so much. It is not until the LFX that some basic reliability issues got addressed. The LGX if a good engine, but that is a totally new architecture with new bore spacings and a new AFM setup. They should have continued to build the V6es off of the 5.3L LS design giving a 4.0L V6. Power would have been 220 to 240 hp for a port injected 4.0 V6 engine. The current LT based 4.3L V6 makes 297hp. These would have been more reliable engines for the Malibu, Impala and all the crossovers. Probably more efficient than the 4-valve 3.6 too.
  25. Nonsense, nonsense and nonsense. (1) You can put a unique serial number and hand build a Small Block. Oh wait, the LS7 was exactly that. (2) Hot Vees do not require any higher or lower tolerances than side mounted turbos. (3) As I have said, an LT based engine displacing 6.8 liters and featuring individual butterflies, cam-in-cam dual phasing and dual injection will produce the same power (~550) with zero lag and with less complexity. As previous small block engines have proven, fuel economy will be equivalent to, or better than, DOHC powerplants of lower displacement but with a similar output (turbocharged or otherwise). The point here is that the Pushrod design is nothing to be ashamed of. It is a GM asset which should be maximized not shunned. It should have been in the ATS-V and it should be in every flagship Cadillac. Whatever displacement taxes may or may not exist in certain markets is irrelevant to this category of vehicles.
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