Warm up time

[CrisSilberGrau]

Good point about rasp Cris If you stay at 3k while warming up, you won't produce that hard rasp we make at what, like 3.5k or so?

Rasp comes on full bodied at 2.2-2.5k with oem Uros and scza, beautiful tone and loud for my setup . Those first few hundred feet when cold I adore.

[Tbonem3]

Good point about rasp Cris If you stay at 3k while warming up, you won't produce that hard rasp we make at what, like 3.5k or so?

[Tbonem3]

Is the 3k figure stated in the manual, or did someone come up with that and we just follow along with it? Why 3k? Just curious. I’ve been doing it since the day I got my car, but I never really questioned why it’s 3k and not 3.5k or 4K.

I like that area of the powerband because you're not lugging and you've got good torque, but it's not too many RPMs, so less wear, while oil reaches temp. I don't try to hit exactly 3k anyway - just somewhere around 2.5-3k. Also, you don't engage Vanos yet, which I assume works better once oil is warm - just a guess.

I do believe, however, that BMW has specified 3k RPM as a good place to get to for a sustained period if you've been in traffic for a while/stop and go/low rpms

[CrisSilberGrau]

Oh another one of these, good cause I changed my routine.

Strat driving right after the rpms drop a bit from start, usually 10-20sec, then slowly rev to 3k in 1st to give my neighbors S54 rasp good and proper.

[SQ13]

Is the 3k figure stated in the manual, or did someone come up with that and we just follow along with it? Why 3k? Just curious. I’ve been doing it since the day I got my car, but I never really questioned why it’s 3k and not 3.5k or 4K.

[DanAvoN7]

I'm pretty sure that's emissions related. Our cars are great smog factories. Doesn't apply if you ain't got cats.

Our cold start pressure is probably close to 100 psi with how thick that oil is. I doubt you're decimating you're engine if you drive after 20 seconds. Redline coldstart like the Youtubers love to do if that's your thing. Their cars seem to survive... usually.

The factory S54 oil pump has a regulated pressure of 4 bar (58 psi). On cold start idle oil pressure will be ~3.52 bar (52 psi) and when driving at higher rpm the oil pressure will be regulated to 4 bar (58psi).

Warm idle oil pressure is ~18-20psi.

[Arith2]

I'm pretty sure that's emissions related. Our cars are great smog factories. Doesn't apply if you ain't got cats.

Our cold start pressure is probably close to 100 psi with how thick that oil is. I doubt you're decimating you're engine if you drive after 20 seconds. Redline coldstart like the Youtubers love to do if that's your thing. Their cars seem to survive... usually.

[Tbonem3]

20 seconds seems a little early to start driving.

[DropTopKingM3]

The highway is within walking distance from me. So if I'm about to drive my car on the highway from a cold start, I usually allow 2 extra minutes until the warm up bars start dropping.

[Arith2]

I've been thinking about this post.

I have a 950 idle rpm and oil pressure is not an issue. The thickness creates more than enough oil pressure. Cars typically have 4 to 5 times the warm idle oil pressure when started cold. Loading the engine at super high oil pressure is not a good thing to do. On the flip side, idling isn't the best for an engine either. I'd say a 3 to 5 minute wait would be good enough to start warming everything up but not soak the oil in gas. Idling at a stop light with the oil at temp is probably the worst thing we can do to our engines. That is when oil pressure is at its lowest.

On a cold start, oil is everywhere in a couple seconds. I'd say, waiting 3 minutes or 10 minutes will probably not have much different results. Waiting 20 seconds or 30 minutes will probably cause very minor wear. Gas will get in the oil from on that engine idle time. After 4k miles my oil smelt a lot like gas. Just avoid stop and go traffic as much as possible.

[Arith2]

Which is exactly why you want to drive it straight away. Oil pump is mechanically driven so lower rpm = lower oil pressures. Then there's the added benefit of actually circulating oil everywhere and getting all the parts in the engine up to temp at the same time, instead of creating a temperature gradient (and thermal expansion gradient).

I assumed the thickness of the oil creates a couple bar. I didn't want to drive with too much oil pressure which causes issue in and of itself. Rod bearings aren't properly protected at high or low oil pressure. I also know idling isn't great for cars so I'll just drive it within a couple minutes. 20 seconds seems a little early to start driving. I'll go to my neighboring BMW techs and see if they know why the manual says that.

[heinzboehmer]

We really pour maple syrup into these engines

Which is exactly why you want to drive it straight away. Oil pump is mechanically driven so lower rpm = lower oil pressures. Then there's the added benefit of actually circulating oil everywhere and getting all the parts in the engine up to temp at the same time, instead of creating a temperature gradient (and thermal expansion gradient).

[Arith2]

Well I've been doing it wrong.
I don't drive it until the oil temp starts to move. That can take 15 to 20 minutes. We really pour maple syrup into these engines so it worries me but hey, if you guys aren't spinning bearing doing this, I'm all for not contaminating my oil with gas.

[Exclusivs]

Because the timing is literally retarded (overly PC people, eat your hearts out) to help heat the cats and incrementally moves towards normal over the course of a minute or so. The exact duration I am unsure.

Exactly this.
One of the reasons alone id love to go euro headers or others ...


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[jbfrancis3]

If anyone with a CSL conversion wants an absolutely perfect cold start and great cold characteristics with higher duration cams, get in touch with paulclaude. The improvement after he adjusted the cold start maps in my DME was spectacular. He noticed too much cold start enrichment

Actually, all starting in general is now absolutely perfect, cold or warm.