dwightlooi

Not really... There are certain parts of the car which are easy to substitute materials for. For instance, you can lighten the Zeta if you go to Aluminum Hoods, Fenders, Trunk Lids, etc. It is a lot harder to introduce a cast magnesium firewall cross member or high strength steel in the stressed underpan or tunnel if the platform was not originally designed around them. In short, Alpha will be able to achieve a greater degree of mass efficiency than a Zeta retrofitted with light weight materials where practical. However, Alpha may also be innately more expensive because of the compulsory elements designed into the platform.

This is how I'll position the various versions... Basically, only the Vette and Cadillac will get the high performance, high compression, independent VVT, premium fuel version. Everybody else will use the Vortec.

Well, they are keeping a Pushrod V8 for sure. This leaves three possibilities.. Use a smaller displacement V8 in the 300~330 hp bracket in the entry level big Trucks and SUVs, use a 4.6 liter Pushrod V6 of similar output or use the 3.6 DOHC V6. The 3.6 DI engine is really ill suited for the role with a 5200 rpm torque peak, only 270~278 lb-ft of twist and probably higher costs. A 4.8 or 5.3 V8 is smoother but also higher consumption. A 4.6 Pushrod V6 will have enough torque, a low enough torque peak and better fuel economy. As far as refinement goes, it'll be OK but not stellar. If the customer cares that much but this, they can order the 6.2 V8 option. A 4.6 Pushrod V6 is also arguably a better engine for the Caprice PPV or the Camaro V6 than the 3.6 DOHC.

I hope they keep it simple and stick to one displacement. A 5.3 will not have significant fuel economy advantage over a 6.2 and the ower bracket servved by the 5.3 is probably better served by a 4.6 90 deg pushrod V6 of (300~315 hp) derived from the 6.2.

The 4.5 IS a reverse flow engine to begin with. It is also a 72 degree V8 -- that rather than the reverse flow setup is a first for a V8. Development on the engine was basically completed in 2008. The introduction was canceled due to the bankruptcy and preceding upheavals. You can probably make a 150~160hp / 260~280 lb-ft four potter by chopping it in half.

3.3 Liter Inline-4, IBC Pushrods, 4-valves per cylinder, Direct Injection -- sharing the rods, pistons, valves, etc with the Duramax 6.6? Should be good for about 200 hp @ 3200 rpm and 380 lb-ft @ 1600 rpm. Not bad for a light truck like the Colorado or Canyon, especially if paired with the 6L80 6-speed auto. With a pair of balancer shafts and given the lowish redline, its probably not even that bad in civility.

I am not saying that they won't or that they haven't. I am saying that they shouldn't. Making annoying decisions like these and making unwise decisions like concentrating heavily on one segment of demand (like big SUVs in the 90s) make for bad business that led to GM's downfall. Making "Green" decisions that pander to the political class and environmental lobbies and ignoring what a large chunk of consumers really want is equally bad and may play out to become the folly of the new millenium.

(1) I believe that GM should build a full range of products covering high performance, high refinement and high economy biases. It should then allow the market to decide if it wants to comply with CAFE or pay the penalties. It won't be a PR problem at all. If consumers make fuel economy the top priority like the political class, all is well. If they don't, GM can point to the Volt, the Cruze and the eAssist Lacrosse and say we have all the fuel efficient products anyone could want, but they are not buying them. And tell the Washington that, perhaps, America does not agree with them. GM's job as a business is not to push any environmental or political agenda, it is to fulfill market demand and turn a profit. (2) You can meet the power levels with existing 4-cylinder power plants. Actually, you can easily exceed it and do it with better MPG. But that is not the goal. The goal is not to to build the most powerful 2.0 liter engine, the cheapest or the highest MPG. The goal is to surpass the 3.0~3.6 V6 in refinement and get in a lower the displacement tax bracket in some markets. And, in doing so create a differentiated product with no direct competition. (3) An inline engine will be VERY long. This will make it difficult to employ in transverse applications. In the case of Volvo, they had to make special provisions in their platforms and utilize a fold over transmission design to fit an I6 in their FWD cars. A V6 will basically fit in the current platforms and use the current transmissions.

I have already explained why I don't think CAFE is that important. Nobody is saying don't build cars that maximizes MPG and meet or exceed CAFE standard. By all means build a full spectrum of them. However, there also exist a very large segment of the market which values other qualities of a vehicle -- refinement, power, etc. -- over the environmental aspirations of the political class. If you want their money, you need give them what they want! And, if nobody else is giving them what they want but you, that's very good for business. At the end of the day, the market rules.

No Complaints from me except that the fake wood looks REALLY fake. 177 hp is fine, silence is gold. Performance is not that important in this segment... think about it, the TSX sold fine, so did four cylinder Camry's. Not everybody is looking for a fast ride or even a merely sprightly one. Besides, they may build a Verano GS with a 2.0T engine later.

$100K V-12s are nice halo cars. But they are not that important. The ATS, CTS and SRX will be the bread and butter cars. Succeed with these (especially the ATS) and you'll have all the budget and clout you need to advance the brand. Fail there and nothing else really matters. Price point wise, Caddy is doing good. Expensive is not better. Expensive in and of itself doesn''t earn you much prestige. $29~45K for an ATS (including the V), $36~60K for the CTS and $35~50K for an SRX is a good pricing strategy. Quality, ride and handling are almost there -- only small tweaks and attention to detail is needed to get them over the line. The biggest problem now is weight. Let's hope the next generation Zeta II based CTS and Alpha based ATS will chip away at that.

A 2 liter class V6 is not very big... Here's a 1845cc V6 in a very small car (Mazda MX-3)... CAFE does not change consumer desire to have the smoothest engine they can buy. In general, especially for cars like a Buick or Cadillac refinement is better selling point than an mpg or two or three. And a selling point that you have, but your competitors do not is more valuable to a salesman than one that is shared with dozens of other vendors. In any case, I have always been a proponent of ignoring CAFE completely and building cars consumers want to buy and not what the environmental lobby or the political class thinks ought to be sold. CAFE is not a mandated requirement like the airbag laws. CAFE is a fuel economy target which manufacturers have the full freedom to choose to meet or pay a small fine per vehicle for not meeting. The fine is actually quite minimal per vehicle (see below *) * Let's say CAFE is now at 35 mpg and GM comes in at 31.3 mpg (31.3 mpg is where they are today). By missing by 3.7 mpg, they pay a fine of 37 x $ 5.50 per vehicle sold. That's $203. GM can add that to the price tag if they want. Let's get real, how often is a $20,000 purchase made or broken over $200? Also, GM is free to implement a fairer system of passing on the CAFE penalties. They can make it such that cars not meeting CAFE pays more (say $1 ~ $600 more depending on their consumption) whereas those that do pay nothing. The formula is simple CAFE surcharge = (total CAFE penalty) / [(CAFE requirement - This Vehicle's MPG) / SUM(CAFE requirement - Every Vehicle not meeting CAFE's mpg)] Then just leave it to the consumer to decide if they want a fuel sipper or high performance vehicle. Then just build as many Volts, as many Cruzes, as many Corvettes and as many Escalades as the market demands -- let CAFE fall where it may and give consumers the choice to pay and pollute if they want or be green and save. It would be one thing if GM doesn't have a full range of choices should the market sway towards fuel miserly vehicles. But GM is bringing out all the appropriate products to present them with that choice. Now let them choose; don't try to force either 35 mpg or 600 hp down their throats. Let them choose. Doing otherwise is simply bad for business and bad for liberty. Remember, whoever is in the White house do not represent the values of all Americans, at best he represents 40~45%.

BTW, a "Reverse Flow" V6 is one where the exhaust exits in the valley of the Vee instead of the outside of the engine. The intake ports are on the outside. This permits a single turbocharger to be used instead of the traditional pair. Larger turbos tend to be more efficient than smaller ones, and one is definitely cheaper and simpler to route than two. A few example of reverse flow engines are the 6.6 & 4.5 Duramax turbodiesels, the BMW 335d's Diesel V6 and the BMW N63 Turbo V8 in the 2008-present X6 and 750i.

Iron is used because the 2.0 is supposed to share components and construction tooling with the Family Zero 1.4 liter four. This engine has very narrow bore spacings making aluminum problematic. Iron Blocks are not all bad. They are stronger than Aluminum blocks for a given material thickness. This means that the bore centers can be closer and the engine can be smaller. They are also cheaper. This is not so much because iron is cheaper (even though it is), but more because there is no need to have separate iron cylinder liners, Silicon Impregnation of the cylinder walls or Iron Coated Pistons*, hence the manufacturing process is simpler. Iron blocks are also stiffer for a given construct, meaning resonances are moved to a higher frequency making the engine note more refined. In the end, iron is heavier, but that extra 10~20 lbs probably doesn't matter a very much in the overall weight of a 3000+ lbs vehicle. * You never want to have Aluminum-on-Aluminum frictional contact because frictional coefficients and wear are very high. Hence, Aluminum block engines either have iron liners in the cylinders, iron coated pistons or silicon grains impregnated into the cylinder walls such that (after some of the aluminum wears away during break in) you end up with silicon-aluminum contact.

What's worse than a bad product is an undifferentiated product. So, here's an idea for an engine which is not currently available from GM's competitors... Type: 2.0 liter reverse flow 60-degree V6 Valvetrain: DOHC 4-valves per cylinder, Intake & Exhaust VVT Construction: Iron Block, Aluminum Heads Balance Shaft(s): One Fuel Injection: Common Rail Direct Gasoline Injection Bore x Stroke: 72.5 x 82.6 mm (Same as 1.4T) Bore Center: 82 mm Displacement: 2046 cc Compression Ratio: 9.3:1 Aspiration: Turbocharged and Intercooled; 1 x Garrett MGT22 Turbocharger Fuel Type: 87 Octane Unleaded Gasoline Power Output: 250 bhp @ 5000 rpm Torque Output: 270 lb-ft @ 1800~4800 rpm Maximum Engine Speed: 6000 rpm The idea here is not to build the most powerful engine or the most economical engine. The idea here is to build an engine that is smoother than the typical 3.0~3.6 liter class V6, that has comparable power output and whose low displacement puts it in the same tax bracket as 2.0 liter Inline-4 powerplants in countries with a displacement tax. The engine is smoother by virtue of its low reciprocating mass, relatively short stroke and the presence of a balance shaft (a rarity in 60 deg V6es). For reduced development and production costs, the engine uses the same pistons, valves, springs, connecting rods and combustion chamber geometry as the 1.4 Turbo engine deployed in the Chevy Cruze. The single turbocharger provides responsive power comparable to 3.0 liter V6es with superior torque. Fuel Economy is expected to be similar to 3.0 liter V6es.

Well, the Turbo in the Car is a Honeywell-Garrett GT15. You may be able to ramp the boost up in the mid-range and get the engine to about ~175 lb-ft at the cost of a good deal of linearity. But you really don't have the airflow capability from that 44mm compressor to get much over 138 hp... maybe 150 or so at about 4500 rpm or so from more boost, then its downhill from there. This turbo (all the really small ones from any maker for that matter) has a rather poor turbine efficiency (62%) which probably accounts for the so-so response and inability to hit the torque peak at say 1400~1500 rpm rather than the 1,850 rpm mark.

A small displacement "Small Block" is not really a good idea. Not that a small displacement V8 is necessarily a bad thing, but the small block's 111.76 mm bore center is really better suited to something around 5.5~7.0 liters, not 4.0~5.0 liters. The 4.3 had a 95 mm bore, that's almost 17mm of metal between each cylinder. This is completely unnecessary for strength. It also makes the engine unnecessarily big and heavy (a lot of useless metal) for a 4.3 V8. If the idea is to create a 4.3 V8, a 102 mm (same as Northstar) or 103mm (same as 3.6 HF V6) will be a better choice. These will yield a smaller and lighter engine. Make a small block displace that few cubic inches, is like deboring and destroking a 3.6 V6 to 2.4 liters. You'll end up with a 2.4 liter engine that is heavier and no smaller than the 3.6 while making less power and torque.

Try attaching a potentiometer to your TPS...

The problem is that a sharp, fast shifting transmission is also a "crappy and annoying transmission" to the average Lexus ES350 or Toyota Camry driver. Many drivers out there have no desire or propensity for spirited driving. They may only floor the pedal and see north of 4000 rpm once a year. They want a slow, smooth and imperceptible transmission that "glides" not "shift". The "right" tuning is something that means very different things to different people. This is why some cars have a sport and a comfort mode. Unfortunately, even then the engineers' hands a half tied since not everything can be handled via programming alone. A lot of the behavior is governed by the size of the orifices in the valve body and the design of the clutch packs. In short, you can't have it perfect both ways.

CVTs can be lazy too.... and for the same reasons. Move at a lower speed or hold the tall ratio until a higher throttle point is reach for economy reasons or refinement reasons or both.

Lotus today is more a chassis and suspension tuning house than an engine builder. The Lotus Elise uses the Toyota 1.8 (2ZZ-GE) I4 engine from the Toyota Celica GTS. The Lotus Evora uses the Lexus 3.5 (2GR-FE) V6 from the ES350. Their future Esprit and Elan models will use the Lexus 5.0 (2UR-GSE) V8 from the IS-F and the Toyota 4.0 (1GR-FE) V6 from the... uh... FJ Cruiser / 4-Runner. Judging from the roadmap, it appears that they have given up on their indigenous engine program and have chosen instead to procure well funded, volume produced and reliable Toyota powerplants. That's not a bad thing. It's probably the smart thing to do. But, it doesn't make them a good engine builder to partner with. If you are look for low volume engine help, Yamaha might be a better choice. Traditionally, they had worked for Ford and Volvo, but as a 3rd party contractor I doubt there is any legal or ethical loyalty to speak of.

I think that is one of the biggest misconceptions surrounding turbines -- that they need to breathe a lot of air. The fact is that a gas turbine making 200 hp breathes about the same amount of air as a piston engine making 200hp. It breathes the about 14~15 times as much air as the fuel it needs to burn to make 200hp. The difference here is that the 200hp piston engine is the size of large ice chest. The 200hp turbine is the size of a stack of 100 CDs. So... while a turbine sucks a lot of air for its size, but it does not suck more air than a comparably powerful piston engine. If your intake and filtration system can efficiently feed a 200hp V6, it can feed a 200hp gas turbine. You don't really control the air. There is generally no throttle plate on a gas turbine engine. You control it by injecting more or less fuel just like in a diesel engine. When you put in more fuel, the engine initially runs slightly rich, but you also create more exhaust energy. This in turn spins the turbine faster and faster to supply more and more air. After a while the engine stabilize at a new equilibrium speed. Another thing about turbines is that they are really efficient only at one narrow speed range. The reason being that their compression ratio is directly proportional to their rpms. They are quite in efficient when changing speeds or operating at a sub-optimal rpm. This is why using them in a series hybrid arrangement is perfect. You get to run them at the optimal speed or not at all. Instantaneous power demands are handled by the battery.

For that 500 a year halo car costing $250K, it shouldn't be the regular production flagship but a specialty model. Cadillac Halo COGAS-E (COmbined Gas And Steam - Electric Drive) Primary Power Source: General Electric Gas Turbine Generator (150kW) Secondary Power Source: General Electric Steam Turbine Generator (50kW) Propulsion Motors: 4 x 149hp Electric Motors; two at each axle. Battery: 4 kWh Li-Ion Transmission: None $250,000 Why plug into the electrical grid and buy power from the utilities companies when you can generate your own the same way they do and with close to the same efficiencies? The Gas Turbine and Steam Turbines are about the size of a turbocharger BTW.

Recalling a point made by a poster earlier in the thread, the Caddy Flagship needs to be an S-class or 760Li fighter. It shouldn't be a 150 cars a year Maybach. The engine needs to be economical to build. Sharing the pistons, rods, springs, lifters, valves, injectors, studs, you name it with a mass production V6 makes things cheaper. A V12 is nice, but realistically the car will also probably have a V8 sibling. To make the entry price more attractive, the electric portion can should probably be optional on the V8 models. So the lineup will probably be:- Cadillac STS eV12 600hp DOHC V12 + 149hp / 4kWh electric drive Hydramatic 6L90E 6-speed Automatic Transmission $120,000 Cadillac STS eV8 450hp Pushrod V8 + 149hp / 4kWh electric drive Hydramatic 8L80E 8-speed Automatic Transmission $90,000 Cadillac STS V8 450hp Pushrod V8 Hydramatic 8L80E 8-speed Automatic Transmission $80,000

Actually, it'll be a lot easier to get it right by basing it on two Malibu V6es than to design one from the ground up. The combustion chamber, the piston shape, the rods, the valves, the valve angles, the injector locations, all of that will be known, proven quantities. The current 312hp 3.6 liter V6 making 87.5 hp/liter on 87 octane is pretty much state of the art in terms of mass production engines. No, it is not a high strung Ferrari V12, but you don't want that in a luxury car -- it won't be refined and good luck trying to find an automatic transmission compatible with its 8300 rpm shift point. Putting the Volt motor-generator on the rear differential along with 1/4 the Volt's battery capacity will bring the V12 to about 22 mpg (Maybe even 23~24 but I am being conservative here) in a heavy 5200 lb car. Doing so also separates the motor from the transmission such that you don't have to worry about finding a tranny that will handle both the V12's 550 lb-ft and the Electric Drive's 273 combined. That is good enough. The overwhelming fraction of Ultra Luxury buyers are not extreme tree huggers. Those that are can buy something else. As far as perception goes, nobody is ever going to look at the V12 emblem and the 12-potter under the hood and say -- oh, that's a Malibu Engine, or that's two Malibu engines.