Started by Ascari32, July 14, 2020, 09:40:13 PM
Quote from: Colin Edwards on July 16, 2020, 11:02:43 AMGoogle "Holden High Features Engine".Not sure I agree 100% the 3.2JTS is enigmatic. Alfa did a pretty reasonable job of coaxing an additional 22kW out of the JTS compared to a "similar" GM/Holden 3.2.Likely much of this came about via adopting direct injection and upping the compression ratio considerably. Both of these measures will increase torque, however Alfa managed to get their 3.2 to produce more torque at higher revs - more power!Unfortunately the higher combustion pressure and temperature hurts emissions / NOX etc. Its no wonder the manifold cats get so hot. The relatively small combustion chamber surface (including piston crown) of the JTS will conduct less heat away compared to say the big bore 12 valve 3.0 Busso.Alfa (and their lawyers!) would be happy to have these manifold cats get stinking hot soon after starting. This feature allows the cats to do their job and clean up the emissions when the rest of the engine is relatively cold. An issue VW had a problem with?Seem to recall reading somewhere Alfa did some clever stuff with regard to cam phasing at low load / low rpm in order to introduce a bit of EGR and drop combustion temps a bit to manage NOX. Also recall mention of the 3.2JTS able to run very lean at low rpm / low throttle openings. All to do with meeting emissions.With regard to scavenging, its possibly less important with direct injection as the fuel mixture needs to arrive in the combustion chamber at precisely the correct moment. Easy to do with electronics and a bit of code. Controlling scavenging in a very precise way could be difficult, hence the popularity of turbo charging?Colin.
Quote from: sportiva on August 02, 2020, 08:08:16 AMFound a badge for your car that was assembled in Pomigliano d'Arco by F.I.A.T SPA
Quote from: kaleuclint on August 02, 2020, 03:18:58 PMQuote from: sportiva on August 02, 2020, 08:08:16 AMFound a badge for your car that was assembled in Pomigliano d'Arco by F.I.A.T SPA Let's be clear. Pomigliano d'Arco was never a 'Fiat' plant pre-takeover. It's the spiritual home of Alfa Romeo Avio and the place where the RA 1000 RC.41 engine was built (in the first factory), powering the Macchi C.202 in my avatar!. Might not be Arese, it's not Milan, but it's Alfa heritage.I don't have any issue having Fiat Powertrain Technologies product (the TBi) under my hood. Serious admiration for the technical knowledge conveyed in this informative thread. If only you were actually consulting to FCA...
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