Quote:
Originally Posted by FreshFRS
eaton did prototyping on the 2009 cobalt SS turbo. they found that from a 30kph roll in 3rd gear (~1100rpm) the supercharger got 90% boost in .5 seconds v.s almost 5 seconds for the turbo. they compared this to a bigger n/a motor (2.8L v6). the v6 has 29kw of reserve power in .5 seconds from 2000rpm cruising (thats the baseline for the test).
the 2.0l turbo produces only 15kw in .5 seconds at 2000rpm cruising therefore must be up speeded to ~2500rpm to make the same power. while the fuel economy is still better than the bigger motor gotta be faster to get the response of the bigger motor. save ~9% fuel economy wise
the supercharger in comparison makes 34kw in .5 seconds allowing the engine to be downspeeded to ~1800rpm to make 26kw in .5 seconds therefore it increases fuel economy on the cobalt platform by 14%
For reference audi's A6 3.0SC manages 11.3L/100km vs. BMW 535xi 3.0TT at 11.8L/100km
Reference: http://www.engine-expo.com/forum_200...rt_walling.pdf |
The 3rd gear 1100rpm example shows that they were pretty desperate to make their SC look good. Because of how biased that article is, and how hard small TVS chargers are to find, I don't have a tremendous amount of faith in Eaton. I want to see an unbiased TVS vs Lysholm comparo, same engine, same boost, properly sized to see how they do in the real world.
Seriously, 1100rpm in 3rd...