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Everything posted by Porter

  1. I suspect the quoted figures have been crank output, not wheel HP. I'm also interested to see how the 2WD DCT does in the real world. That's a lot less driveline lash to cope with compared to AWD, so it would likely have different shift logic than the AWD application.
  2. It's chain-driven. Interestingly, the timing chain drives a cog which drives the input gearing on each cam. The input gearing on each cam timing control assembly is also directly geared to the one on the other cam, so there is always a physical reference keeping the cams tightly in sync with one another. This is in contrast to systems that are only driven by the chain per cam, which then has the dual job of both driving the input gear and establishing the per-cam timing reference. In addition to preventing the cams from ever being out of time with each other, this AMG system should have less variable force on the timing chain per engine cycle and I expect would have a far longer service life for the chain.
  3. It's for emissions. A closely coupled catalytic converter heats up more quickly on cold start than one that's further down the pipe. Some manufacturers were even doing pre-turbo catalytic converters for a while in the mid-2000s in an attempt to improve cold-start emissions. Placing the catalytic converter after the turbo is always better for spool-up of the turbine though, and thankfully most manufacturers have now standardized on engine packaging and exhaust routing that places the turbo (or turbos) as close to the exhaust ports as possible. That's the reason for the "Hot V" architecture of many recent V6 and V8 designs.
  4. Very interesting screenshot from the A New Dawn documentary. Looks like an M139 in testing in an Evora test mule. The positioning and exhaust design are particularly interesting. See this cutaway model for reference - looks like Lotus are using a close-coupled catalytic just after the turbo hot side exit, similar to the A45.
  5. One of the powertrain test mules was shown in the documentary Lotus: A New Dawn. Very, very interesting.
  6. My guess is turbo, intercooler, and mapping. Possibly exhaust differences too, but the turbo itself is the most likely. There may also be fueling differences.
  7. Near Washington DC, in Alexandria, Virginia.
  8. Deposit in on the new Emira. Looking forward to joining the Lotuscenti if everything goes to plan. I've been lusting after Lotus' since the late '90s when I first really became aware of the magic of the Lotus/Caterham 7. Anyway, glad to soon be part of the madness. If I'm going to buy my last internal combustion sports car, I feel like this is a good'un.
  9. I suspect that Lotus are hedging their numbers a great deal due to this being a world car and needing to tune appropriately for available fuel in all markets. I think they are also sandbagging the 0-60 time so they can exceed expectations when the initial press cars get reviewed. As Matt Windle said on one of the videos, the V6 should be essentially the same packaging as the existing Evora (416hp on EU/US super premium fuel). If the pattern continues, the AMG I4 will likely be in a similar state of tune to the non-S AMG45 M139 currently on sale in other vehicles (382hp on EU/US super premium fuel). "Super premium" is normally US ~93 octane (average of RON+MON) or EU ~98 RON. My guess is for a 0-60 in the AMG powered cars of around 3.9s, maybe less. Journalists are getting that today in the CLA45s which has a little more power but WAY more weight to move. In other places around the world, where available max octane is possibly lower, it may truly be a 360hp output car and only see 4.5s to 62mph/100kph due to far less aggressive mapping on that fuel. I don't think that will be true in markets like the EU or US though.
  10. Is that an air-to-water intercooler that I see? That makes packaging the cooling a little easier.
  11. The build process for the M139 is pretty epic to watch. I think it might be the engine to consider.
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