11-16-2019, 04:39 PM | #1 |
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Possible to have cold starts with closed wastegate instead of open?
My mom has a 2014 gl550 with the 4.7 L twin turbo v-8 and when it goes through its cold start you can hear the turbos spool which I am assuming means that the wastegates are closed (pneumatic)
now is that possible to get a turbo spool when we start up our cars (close EWG) I have catless downpipes and a custom axleback so I can hear it when in sport + but cold start turbo spool would be nice (if you listen closely you can hear the distinct turbo spool) |
11-19-2019, 08:23 PM | #3 |
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11-20-2019, 11:35 AM | #5 |
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11-21-2019, 01:56 AM | #6 |
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BM3 should have a provision for a “cold start delete” if I recall. That may keep the waste gate shut, or it may not. Worth a shot if you are catless. Otherwise there may be slight risk of damage to your cat. Not sure how much open WG matters, but it definitely has a purpose.
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11-23-2019, 10:28 AM | #7 | |
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11-25-2019, 08:53 AM | #8 |
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It does a little more than just idle RPM. The factory cold start setting actually retards the ignition timing a lot, to put an artificial load on the engine to raise EGTs enough to heat the cat up quickly. The timing is pulled so far back that a lot of combustion is occurring outside of the engine (to heat the cat up), hence why cold start is so obnoxiously loud. It is probably doing some adjusting to the vanos and valvetronic as well.
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11-26-2019, 01:36 AM | #9 | |
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However, in the context of the waste gates opening or closing, the BM3 cold start delete is still irrelevant.
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12-05-2019, 08:56 AM | #10 | |
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