Megasquirt Support Forum (MSEXTRA)

Just wondering....

In the current MS2 code, the cold advance does not apply to the cranking advance, only once out of cranking and in engine ready/run.

Is that right? Should the cold advance only apply when running? Why wouldn't you want to have the increasing advance applied at cranking? It would seem logical that if the engine runs better with more advance when cold, wouldn't that apply in cranking? ...or is the logic to essentially have the maximum possible advance at cranking anyway and that more (or less when warm) doesn't help.

G

The "cold advance" is perhaps a misnomer.
In another source I read that
-in a race car, advance when cold due to high-lift cams etc.
-in a car with a catalyst, retard when cold to increase exhaust temps and light up the cat.

Cranking isn't trying to do either of those and too much advance risks kick-back.

James

A cold advance cranking curve ( or whatever it could be named) would be very useful for the guys who runs 100% ethanol (80% of the cars here in Brazil). The cold crank in gasoline or even E85 doesn't need more advance than 6-12 degrees in cranking to have a solid start, but an engine runnign E100 need up to 35-40 degrees to start under 20ºC ambient. But this level of advance cause kickbacks in hotstarts, obviously. Unfortunattely we have to live with a more than ideal advance to hotstarts and less than ideal in coldstarts. I already had some broken starters due to kickbacks in engines running MS2.

I would be very glad if a cranking advance versus temperature curve where placed in the to do list.

There is a bit of incidental information on Google to suggest that more advance when cold cranking is helpful, and less during warmer cranking. Would be easy to adapt the existing cold starting advance to be applied/added to the cranking advance too!

G

gslender wrote:There is a bit of incidental information on Google to suggest that more advance when cold cranking is helpful, and less during warmer cranking. Would be easy to adapt the existing cold starting advance to be applied/added to the cranking advance too!

G

It would probably be well worth it, but it needs more range than current 10 degrees max for many applications.

I have , ms2 and ms3 , and i use 100% alcohol , i would like to have this implementation , crank advance for temperature.

This would be an interesting feature, for those who run E85 or E100 blends.
It will REALLY improve the cold starts!

Do they have any prediction to insert this into the code?

I have one ms2. Please add this to the code.

I have a MS2, and I would like to have this implementacion!

any prediction for this? It's winter in Brazil, the cold start is very difficult

Hello! Good night everybody! Is there any forecast to implement this fix in code?

They do not care about us, they forgot about us.

we will continue to be ignored?

I suspect someones going to have to code it on the previous version and hope the devs import it.

folks running e100 are few and far between here, even all my local e85 pumps have been converted to e15 pumps, which no one will likely never intentionally use.

here in brazil all pumps are E100, and all that have turbo car use E100

Your best bet to make a case for temperature dependent cranking advance would be to gather data logs of cranking at different advances and temperature to demonstrate better starting at different temperatures with different amounts of timing.

Could you please implement this function? Would help us alot, that run E100.