Programming in Cold Weather

[Chris74]

Well Corey, it's pretty normal to get that cold here in December through February. It's the windchill though that will really bite yah!
We get extreme high's and lows in both winter and summer.......so we just get used to it.
We do take a trip down south somewhere to get a break from winter when we need it though!

[Corey Cohron RIP]

Originally Posted by JackandJanet

Dressed like you (in a loincloth) :covereyes: 5º C (42º F) has to have a pretty severe "chill factor"! :cold: Glad us old farts have warmer climes to escape to.

(This is awful - I could spend my whole life here just thinking of ways to use these smileys).

- Jack

LMAO, Jack! Here I am thinking Loincloth? What the is he talking about? And I just got it!

I know what you mean about these damn smilies. I'm determined to use each and every one of them at some point.

[Power Hungry]

Originally Posted by JackandJanet

Dressed like you (in a loincloth) :covereyes: 5º C (42º F) has to have a pretty severe "chill factor"!

I don't have any choice. That's how Corey dresses me. Notice that my toes are in danger of frostbite, too! I guess when you're a big, tough dude you just have to grin and bear it.

[sonic blue l]

we were down to as low as -36 deg c this week, mind you last year we had times of colder then -40 c.

One question though, is it ok to run a performance tune on a diesel at those temps?

[Jackpine]

Originally Posted by sonic blue l

we were down to as low as -36 deg c this week, mind you last year we had times of colder then -40 c.

One question though, is it ok to run a performance tune on a diesel at those temps?

As far as I know, sonic, once the tune is programmed in, you're good to go! I've never read anything pro or con about using an already loaded custom tune in extreme cold.

- Jack

[sonic blue l]

problem is 6.0l's are a lot louder in cold ambient temps (-20), vs warmer temps even when stock.

Now a tuned 6.0l is noticeably louder then a stock tuned 6.0l in the first place, thus my concern.

I also wonder why the tune has to be louder at idle in the first place, i suppose it could be to lessen fuel usage by advancing timing, etc when idling, but does it have to be that way?

My concern is not really the diesel " noise ", its hard to explain, but if one has ever heard a cold and i mean -30 c cold 6.0l, run then they would know why i might be concerned about tuning on a 6.0l at -30c.

Of course common sense applies to allowing any engine to warm up before driving but my concern is the initial start up.

I guess what im wondering is that on a stock tune vs custom tune is extreme ambient temps taken into consideration?

[Jackpine]

I don't understand what you mean when you say "timing". Is it valve timing? Can this be adjusted on diesels? As you can see, I know next to nothing about this kind of engine beyond the fact that it ignites fuel using compression only once started and that it has more power potential.

I suppose it idles at higher RPM when cold, like a gas guzzler? If so, it's getting a somewhat richer fuel mixture, and maybe the throttle is held a bit more open? Could it be that this is a normal sound at this RPM that is partially masked by road noises if the vehicle is underway?

My sister's truck has the same engine as yours. Someday, maybe I'll talk her into getting one of Bill's tunes for it. And, she's in Colorado Springs, where it gets pretty cold too.

I'd be good if someone with diesel knowledge added their thoughts here. In the meantime, I'll try to keep the thread alive.

- Jack

[Power Hungry]

Just for reference, what gassers call "timing" is called "start of injection" or SOI on a diesel. This is ROUGHLY the same comparison although spark timing on a gas is more of an instant reaction while a diesel has a small delay between the time the fuel is injected and the time it actually starts to burn. This just semantics, though.

Anyway, the reason for the extremely advanced timing in cold weather is because the diesel fuel burns SO SLOWLY at those temps that it can take as much as 20 or 30 degrees more timing just to keep the engine running. Of course, as the engine warms up, the timing will back down significantly.

Diesels also monitor Intake Air Temp since colder air needs to be heated a bit before entering the cylinder. This is what glow plugs and intake air heaters are for. Diesels also use the Intake Air Temp to advance the SOI so the engine can run properly. This is the reason that even with the engine fully warm, it is always a little "louder" in the winter than it is in the summer.

Hope this helps.

[Jackpine]

So, fuel is injected earlier in the intake stroke on a cold engine. Did I understand this correctly? And somehow the effect of that and intake heating cause the engine to be louder. It's great to learn new things!

And, since you didn't say to the contrary, a custom tune will not cause harm in cold weather.

Interesting that a tuned diesel is louder than an untuned one. My guess here is though, that it is getting more gas (so it can develop the additional power) that tunes provide. So, more gas and possibly more air too (to balance things) means a louder burn, right?

- Jack

[Power Hungry]

I tuned program can be harmful to an engine if it is too aggressive, whether it's gas or diesel, hot or cold. The reason tuned diesels are "louder" is indicative of the advanced injection timing and is normal.

In most circumstances, I don't really do much for tuning in the portions of the maps that are below 120ºF. This way it allows the engine to warm up before really putting any power to it. There might be a little timing but that's usually about it.

Diesels are odd engines to understand completely. Gas is much simpler, except for the Air/Fuel Ratio bit.

Take care.