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Turbo
Posted by LDH (more from LDH) on Fri, 19 Oct 2001 12:29:42
In Reply to: What do you guys think about this article, Anton, Fri, 19 Oct 2001 12:02:41
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With forced induction, knock (pre-ignition) becomes a big issue. The Aero ECU is designed to provide maximum performance in any situation while protecting th engine. Low-octane fuel will cause knock at lower boost pressures than high-octane fuel. So, when you put low-octane fuel in your 9-5 Aero, the ECU actually reduces performance in order to protect the engine. Who knows if it's reaction is appropriate or too conservative? In any case, it's built in.
Since the BMW is normally aspirated, they don't have to worry about such things. The BMW engine will have a lower compression ratio than the Aero does when at full boost (turbo effectively increases compression when active). Lower compression will be inherently less prone to knock, which is caused by combustion of the fuel not by spark but by excessive pressure in the cylinder. Some call it dieseling, as this is the principle that diesel engines work on. Higher octane fuel is actually harder to ignite than lower octane, thus high-octane fuel helps eliminate knock.
posted by 151.201.22...
Posts in this Thread:
- What do you guys think about this article, Anton, Fri, 19 Oct 2001 12:02:41
- Honda did lose power with premium ..., Kevin K , Fri, 19 Oct 2001 23:48:37
- There is a gas station about 25 miles away that has..., RedSPG18, Fri, 19 Oct 2001 18:20:13
- you mean switching from premium to regular loss of perf. n/m, J.Ryan, Fri, 19 Oct 2001 14:27:08
- Article says performance loss switching..., saabaru, Fri, 19 Oct 2001 14:16:45
- Page 3 , para. 2 states that the test uncertainity around 3%. N/M, REM in Seattle , Fri, 19 Oct 2001 13:45:59
- Re: What do you guys think about this article, Dean, Fri, 19 Oct 2001 12:39:21
- Turbo, LDH, Fri, 19 Oct 2001 12:29:42 <-- Viewing This Message
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