blaen99

iTrader: (6)

I have:
Brainy-rebuilt MS2
Brainy basemaps
RX7 550ccs
1.6l bignose

So, I've been researching cranking and cold starts. However, I've managed to make myself more and more confused with what I have in my Brainy-provided basemap as opposed to what I'm seeing in the forums.

Let me give an example.



as compared to



If I understand what is going on correctly, the Brainy-provided basemap needs a drastic decrease in WUE fueling, although I believe that's for a MS1 vs. MS2. Am I correct in assuming that the WUE % is way too high (Note: Both are 550cc injectors)?

Secondly, I am confused with cranking pulsewidth. Here is what I have from the Brainy-provided basemap:



Here is the closest I've found to what I'm looking for:



Am I correct in saying that my cranking pulsewidth's are way too high as well, as the latter one is only for 425ccs and the former is for 550ccs?

nitrodann

Does it work?

Dann

hornetball

iTrader: (4)

You are, indeed, confused.

There are four distinct stages of engine operation:

1. Cranking Settings/Pulsewidths: These settings are in milliseconds of fuel injector pulse widths. They cover the time period from when you first turn the key until the engine fires (the MS considers the engine to have fired when RPM exceeds "Cranking RPM"). For comparison purposes, look at pulse width duration and size of the injector. In addition, don't forget that injector dead times can vary.

2. After Start Enrichment. Immediately after the engine fires, things are in a confused state. You will still have a high MAP because there isn't enough RPM yet to generate vacuum. MAP and RPM will be swinging quite a bit in the low RPM region while the engine "catches it breadth." ASE is intended to be a limited-timeframe mode of operation that keeps things stable for a set time period.

3. Warmup Mode. Once the ASE time period expires, operation is handed off to warmup mode. Warmup mode is like normal mode with the exception that fueling in increased based upon temperature. It operates until the engine reaches normal operating temperature.

4. Normal Mode. Congratulations, you managed to start and warmup the car. Now, you're off to the races.

In one of the above graphs, you are comparing ASE to Warmup Mode. These are two completely different things.

Matt Cramer

Good explanation, Hornetball. I'd also like to add that the ASE percentage and the WUE percentage are added together, so these settings "stack," while cranking pulse width is not affected by other settings.

hornetball

iTrader: (4)

Huh. Didn't know that.

In practice, I've found Cranking and ASE kind of hard to tune because they have such short lifespans and you can only hit the point that you happen to be in when you turn the key. Maybe hard isn't the word, you just have to do it fairly often at first, especially when the weather's changing.

Tuning WUE is pretty reasonable. You can use your WBO2 and the change in temperature is gradual. Basically, do a start on a cold day and idle until you've reached operating temperature. During that warmup, you'll gradually hit almost all the cells. Shoot for a % that gives a WBO2 reading similar to your normal warm idle.

Braineack

iTrader: (62)

this is MSII vs. MS1; you can't compare them like this. Plus you're comparing a WUE curve to an ASE curve...

Furthermore, whomever is using that MSII WUE map sucks at tuning. The WUE should never drop below 100%, and its providing an anti-warmup-enrichment table when you consider it's pulling fuel away in situations above 50°F.


Cranking pulsewidth shouldn't really change once tuned--regardless of injector size. The cranking table in the basemap, is the same I use for my 460cc inejectors and the same I use for 230cc injectors...what matters is the REQ_FUEL being scaled properly (notice the values are in %, not raw)

Again, dunno who tuned that MSII, but I'm surprised the car will even start.


But you can disregard my maps and install those peices of ----, it's okay...I wont judge your sadomasticism.

hornetball

iTrader: (4)

I always thought REQ_FUEL affected non-dimensional VE values, but didn't affect values expressed as msec. ?!? Confusing.

hornetball

iTrader: (4)

Never mind. I'm a dumbass. That's one of the differences between MS1 and MS2+. In MS1, it's in msec. In MS2+, it's in %.

Braineack

iTrader: (62)

yep. So Blaen needs to stop comparing the two.

honestly, I'm not sure what the question is.

blaen99

iTrader: (6)

...Yes, but during cranking and ASE warmup it runs like ----.

Thanks guys! That is a bit too much to go over during my lunch break (It'll have to wait untill I get home, big meeting today, bah) but that is lots of info!

Uhm. Oh dear, I linked the wrong images, how embarassing.

I agree, I suck at tuning. But you've explained to me what I was completely wrong about, so thank you very much Brainy!

Uh, Brainy...

The cranking and ASE maps are verbatim from what you gave me, unchanged...If you are telling me to disregard your maps and install those pieces of ---- . The req_fuel was properly set according to your instructions as well that we talked about in PMs!

The WUE is something I've been ------- with over the past 2 days or so to try to make sense of in the 62.0 and higher cells, with the previous cells left untouched from the basemap I received from you. The WUE map does suck and I need to completely re-do it now, but I'm actually not having a problem with it.

Thanks to the wonderful information from everyone above, I either fully understand what is going on, or have a much better idea.

Cliffs:
The problem I've been having has to do with the cranking and ASE maps. Specifically, it doesn't want to start worth a ---- or stay running in the ASE window, but once it transitions over to WUE, it works perfectly.

hornetball

iTrader: (4)

Check your "Cranking RPM." Someone else here just had a problem where their "Cranking RPM" was set too low, and the MS was jumping into ASE prior to actually firing. I'm using 300RPM. Also, if WUE works well, shorten up your ASE time period. There's no reason to stay in ASE longer than you have to.

blaen99

iTrader: (6)

I have it set at 300RPM as is, thank you Hornetball!

blaen99

iTrader: (6)

Just one quick question about this. So if I understand this correctly, all I do is scale req_fuel based on injector values regardless of what the actual tables are then tune the actual tables? Also, the cranking table is independent of the rest of the settings I am working with (ASE, WUE, etc.) as per Matt Cramer's post?

Thank you very much everyone again - minus this one little detail, I actually am understanding this stuff now! Putting up with my nooby questions about this is greatly appreciated.

(Edit) Found at least one major problem now. REQ_FUEL was too low - it was calculated based on 14.7 instead of the 12.2 that Brainy recommended in a post in the past.

Braineack

iTrader: (62)

The only ASE map you posted is MSI, and yes it's mine.

You posted two cranking tables, one is mine (the nice linear one) the other is silly.

You posted a warmup table that's awful as well.


It's not really hard, start the car, and once ASE has timed out, you're in warmup mode until 160°F or whenever you go back to 100%. Just tune it in such a way that your AFRs are in the mid 13s or so. This assumes a tuned fuel map in normal conditions without enrichments. Just look at the table, you're simply adding fuel based on a coolant temp...simple concept.

The idea is just to add some fuel when the temps are colder to keep the AFRs a little fatter during warm-up. I aim for high twelves under 100°F and mid 13s above, where I taper it off as I get closer to 160°F so I idle back at 14.5 smoothly.

My warmup tables look something like this:



Does it struggle to start form lack of fuel? does it struggle to run in ASE because of lack of fuel?

If yes, add fuel to cranking/ASE. If no, remove it at that particular coolant temp.


Is it 5.4? IIRc that's what I'd put a 91 with 550s to.

blaen99

iTrader: (6)

Holy fuckity ---- Brainy, you rock.

That's everything I needed to know and then some. Much <3!

Amellrotts

iTrader: (2)

Sticky? Some great info in this one!