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Hi everyone! This is a question i have asked some of my friends but not asked my dad as im afraid he will laugh at me! About a month ago, i bought a new Corsa SRI 1.4 16v with Twinport. I wondered if anyone could tell me what Twinport is and what it does? Ta!
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uk.cars.yahoo.com/car-reviews/car-and-driving/vaux...l
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Ta very much, Tomo. Looked at that link and it made things a lot clearer. Folk kept saying, "ooh, it's got twinport engine", and i had to pretend i knew what they were talking about! Thanks again!
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VW made their later versions of their 1300 engine twinport too, gave approximately 10% more power.
In 1971, and 10% of naff all isn't a lot but that completes the history lesson.
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>>In 1971, and 10% of naff all isn't a lot but that completes the history lesson.
Looks like they did better than GM Europe in 2005 then!
Reading that Yahoo! article , which, to me at least, appears to have been written by somebody who didn't actually understand a word they were writing, boils down to:-
0-60 improved by <2%
bhp improved by <7%
economy improved by <5%
emissions improved by <5%
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To quote from the Vauxhall website:
snipurl.com/oaqo
Twinport technology builds on the standard four-valve technology of Vauxhall's renowned ECOTEC engines. Savings are achieved via a variable intake manifold in combination with a high rate of exhaust gas recirculation. Under 'partial load' the engine receives an additional 25 per cent of its fuel air mixture from the already burnt exhaust gas recycled back into the mix.
The advantages of twinport technology are achieved through a combination of fuel injection and exhaust emission control by three-way catalytic converter technology. This reduces technical complexity and consequently the cost to the customer, making the twinport solution particularly attractive for compact-class cars, as power output and efficient fuel consumption are maintained.
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"reduces technical complexity and consequently the cost to the customer"
So it makes little or no difference to performance, economy and emmissions, but it makes the car cheaper to build?
"particularly attractive for compact-class cars, as power output and efficient fuel consumption are maintained"
Which wouldn't be attractive for larger cars?
Reading between the lines, it seems like Twinport makes the car cheaper to make, but has so little benefit on the smaller cars, that it is pointless on larger vehicles? Perhaps even worse than the standard engine?
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Twinport is a system which, under part load conditions, partially blocks one of the two branches of the inlet manifold upstream of each cylinder, near to the inlet valve. The extra inlet air turbulence allows the greater use of EGR without the engine mis-firing.
The extra inlet air motion allows for more stable combustion,
allowing more EGR. This extra EGR leads to a reduction in throttling and other thermal losses, thus giving an increase in mpg. There is also some stratification of the charge, giving a richer mixture at the plug, but a weaker mixture overall.
So, Twinport manages the detailed profile of the motion of the inlet charge rather than the quantity or timing of the charge motion itself.
Number_Cruncher
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Thanks NC for explaining the marketing babble in engineering terms, aaprt form your last sentence which I don't understand fullt but get the ghist :-)
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I was thinking that the valves control when the charge goes into the cylinder, the throttle controls how much goes in, and the twinport device controls how the air and fuel behave as they go in, i.e. how much the charge tumbles and swirls.
Obviously, these little flaps are a hindrance for air at high engine speed and load, so they swing out of the way then.
Number_Cruncher
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and there was me thinking it was a "retail outlet" centre! :-)
JH
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