Loren's V8 S10

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Postby Loren » Sun Oct 28, 2018 3:23 pm

I'd consider selling the truck for $5k. I bought it for $6k, and probably have put at least $2k into it. I haven't been keeping track of expenses... it's very likely over $3k. Complete suspension and steering, front brakes, exhaust, ECU, radiator, waterpump, etc, etc.

Anyway, I did get some quality time with my timing map last night, and with the truck this morning/afternoon.

One of the things Andy told me that I thought was very peculiar when he initially set up the MS enough that I could limp it home was "it pings with ignition advance anything over 20-25 degrees". He had set the base timing, and that was his observation... so, he just bumped the offenting parts of the timing map down accordingly and gave it a tune that I could limp it home on.

As mentioned, last week, I needed to "DD" the truck, and I noticed that it did ping in certain conditions. Lacking time, I just set everything over 1800 rpm to 20 degrees, tuned the fuel around it, and limped it around for the little bit of driving that I needed to do.

Last night, I went and created a new timing table that "should" be correct and not overly aggressive. I started tuning the fuel to match that this morning and quickly found that even light acceleration above 2000-2200 would result in what sounded like "lean misfires". Just little pops. No audible "pinging", but very obvious misfires. It was not running lean at all, so it wasn't lean pops. And I wasn't getting on the throttle hard enough for accel enrichment to be a factor. This got me back to thinking "this thing is too far advanced". Andy probably timed it to a mark on the aftermarket crank pulley that just wasn't the right mark, and I'm betting it's probably something like 10 degrees off.

Didn't have my timing light with me, not that I really had the motivation to use it, anyway. So, I experimented.

Little sidebar here: Yeah, I know you're not supposed to mess with timing without KNOWING what your baseline is. But, here's the thing: I'm going to be playing with this timing throughout the range of conditions in time. And just like when you're randomly advancing the timing on any car... you're going beyond the factory spec (there is no factory spec here, this is a highly modified engine!) to a point that you're guessing will work. If you guess wrong and go too far, you're going to back it off. So, the ACTUAL numbers would only be super-important if I was using someone else's timing map from an idential engine and wanted to trust that it was perfect and exactly match that setup. Such is not the case. So, really, "exact numbers" aren't critical. However, numbers that makes sense to me are something I'd like to have. So... let's make the numbers make sense!

I'm getting misfires at 2200 rpm, and timing is only hitting something like 22-24 degrees there. Shouldn't be pinging, but if we're 10 degrees off with the base timing, well, then that's 32-34 degrees... and, yeah, that's a problem!

So, I first fiddled with the base timing adjustment (essentially telling the computer where "zero" is) to determine which was was advance and which was retard. Then I retarded it by 5 degrees, and set out to tuning again.

Feels a lot better down in that sub-2000 range where I'd been driving, and sails right past 2200. Hit that same misfire stumble at around 2700. I think we're onto something! Played with that for a while longer. (really, I just wanted to get somewhere and eat lunch before stopping to futz with the manual adjustments again) Fully verified that it does run just fine right up to about 2700, and it tuned itself in pretty well.

Now, I'm right where I was initially thinking. "The timing was probably 10 degrees off" (probably a "0" mark where the pointer on the timing cover is looking for 10 degrees... something like that). So, I adjusted the base time another 5 degrees. Total change of 10 degrees from where I started. I did have to add some additional advance at idle to keep it happy. (I think the big cam requires more idle advance... it seems to like 15-18 degrees.

Drove that and did some autotune on it. Sure enough, another improvement. It's still not perfect, but I didn't drive it around enough to really get all of the fuel table dialed in, either.

Bottom line for today: I have a more normal timing map, and it WORKS for the most part. Getting closer. Much more drivable, anyway.

And I used to think this truck ran hot before I got the MS running. Now I know that the stock temp gauge is way off! It reads like 230 when the actual temp is something like 201-205. 210 on the gauge is actually a normal 190-192. With the MS controlling the cooling fan and properly set, my fan never even came on this morning... but the temp gauge was reading between 210 and 220 when it was warmed up!
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Postby twistedwankel » Sun Oct 28, 2018 4:28 pm

Some times I feel trapped. Do you?
Hey that's a tempting project.
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Postby Loren » Mon Oct 29, 2018 2:21 pm

More quality time. Learning stuff.

I was mistaken. The base timing was correct to start with. I realized this when I started playing with the timing at idle and realized that I could work within a range of 20-30 degrees, and it actually seemed pretty darned happy at 25 degrees. Now, I know a modded engine will often like to idle with timing in the mid-high teens. But, 25 degrees? Nah. And getting all the way up to 30-32 degrees without sputtering? Nah.

I always thought it was weird that this truck on the stock ECU would cruise at 19-20 degrees of advance, and never ever seemed to go over 21 degrees. But, maybe that's just where it's happy? (or maybe the cam timing is wrong, or the distributor adjustment is that far off, who knows?)

So, I took the whole timing table that I'd been playing with (that just keeps getting better and better) and bumped it down by 10 degrees, and then set the base timing back by the same amount. Now "the numbers make sense", which is good. Idle timing makes sense, and everything else makes sense once you accept that "this engine doesn't like timing advance to come in too early or too much".

Still playing with it. Baby steps.

Another thing I noticed today is that there's a difference between the AFR readings between the gauge and the MS. This is not uncommon, has to do with grounding issues. I always trust the gauge to be more accurate than the reading at the MS, which uses a different ground point. In this case, the difference is significant. When the MS reads 14.7, the gauge reads 13.8! That would explain why it was always idling rich, and always smelled rich.

So, I took my AFR Target table (did I mention how awesome MS is? You get to tell it exactly what AFR you want to tune to at any given rpm and load point... try that with a carburettor) and raised the whole thing by .5. Tuning to that should put me right where I want to be.

I also enabled "overrun fuel cut", which is the same thing they call "deceleration fuel cutoff" or DCFO on factory ECU's. So, when I'm off-throttle, in gear, and coasting down, it shuts off the injectors and uses no fuel. Should easily increase my fuel economy by 10%. (bringing me from 13 to 14.3... yay)

Played with the fan control settings, found that I can add a second option to the fan trigger. It was set to just turn on at 200 and off at 192. But, doing that, if you got hot sitting at a light and the fan came on just as you were leaving the light, the fan would run (unnecessarily) while you were driving until the temperature dropped. So, I added RPM as a factor. If RPM is greater than 1200, the fan stays off. Less wear and tear on the fan. :thumbwink:

I'm getting to the point where I need to just settle on a timing map for a while, get fuel fully tuned to that, and then start logging things. Things like cold starts. Warm starts. Cruising. Various acceleration situations. Throttle tip-in. All of the things.

This is the part that a lot of people can't handle with the MS. It requires constant tinkering for a couple years to really get things dialed in "perfectly", and they want "easy". Well, it is easy, but it takes time and thought and understanding. Personally, I enjoy the challenge.
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Postby Native » Mon Oct 29, 2018 9:12 pm

The fan part made me go, "hmmm."
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Postby Loren » Mon Oct 29, 2018 11:32 pm

Native wrote:The fan part made me go, "hmmm."
I think if you use the regular fan control, as you would on your MSPNP, you may or may not have that option. (didn't used to... but, things change)

But, on the Microsquirt, the "regular" fan control isn't there because there is no dedicated fan output. Because I'm controlling the fan using a "spare output", I have the option to consider two variables for it. Could be any two variables that are available! I could turn the fan on when kPa is less than 50 and throttle position is less than 2%. I'm not sure why I would... but, I could!

Drove the truck down to St. Pete this afternoon. Still needs more work on the timing curve. It's getting there, but it's not there yet. I feel like I've got good control of it now, though. And I've found that place where it runs "okay", and isn't over-advanced anywhere. That's a pretty good place to start.
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Postby AScoda » Thu Nov 01, 2018 7:03 pm

Loren wrote:
Native wrote:The fan part made me go, "hmmm."
I think if you use the regular fan control, as you would on your MSPNP, you may or may not have that option. (didn't used to... but, things change)
On mine, you can. There are 2 separate fan controls, cuz 2 fans. One in general settings, where you can specify conditions for temp, TPS and MPH, and one in 'programmable on/off outputs, where you can specify 2 variables out of a dropdown menu of a boatload of choices.
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Postby Tim_M » Fri Nov 02, 2018 10:04 pm

I think you may find less improvement in fuel mileage than 10% on the decel fuel cutoff. Very little fuel is consumed in that portion of the map, but it is a savings.

You might want to research other's timing maps and start from there...something that has similar idle vacuum. I've not found significant improvements when messing with the timing from established norms. AFR adjustments for sure. Of course, it would help if you could nail down the static timing of the engine for a baseline... :smack:

Working the keyboard tweaking things is addictive. I've had to force myself to leave the laptop at home and just drive the car as it should be driven vice watching the displays and making adjustments.

Stickshifts are much more involved than autos...we use much more of the map as well as the transitions with the clutch, etc. Tedious...likely because I'm not very successful at it.

A V8 S10 is a fun project...
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Postby Loren » Fri Nov 02, 2018 10:15 pm

Funny, I was having a similar thought. Initially, I tried to find a proper timing map for a Vortec 383. Which, of course, doesn't exist... or isn't easy enough to find. But, if I found a timing map for just a basic Vortec 5.7, I could probably use that as a basis.

The biggest problem here is that I just don't want to spend a bunch of time on this truck. I've got it pretty settled right now. It's behaving nicely in "daily driver" mode at present.

Maybe someday I'll get a wild hair and decide that I want to autocross it. Then I'll have to get more serious about it. Fix the oil pick-up problem, address the lack of headroom of the fuel injectors (which will likely require a new manifold, a proper fuel rail, and new injectors), and significant tuning of the 4-6k rpm area. But, all of that takes money in addition to time.

Meanwhile... well, the weather IS getting cooler. Once the Mirage is back together, maybe I'll dedicate some time to tinkering with the truck.
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Postby nathanwilliams617 » Sat Nov 03, 2018 8:44 am

Loren, I've not tuned much at all, so not knowledgeable, but I'll post what I have and you let me know if you can use it or not.

It's a 5.3 vortec out of a 02 Silverado c1500, for my 66 impala. I used Hp tunners software, but all I've done is switch a throttle body control from electronic to manual, disabled the vehicle theft system, down stream O2 sensors, then fired up the engine. I have not touched any of the fuel maps etc. If I were to somehow export that data, would that be helpful?

Also I've not touched this project in like 4 yrs, so I don't even know if the laptop will fire up or not, but I'll dig it up and try if you think you can use the data.

I see potential issues 5.3 vs 5.7 and Hp Tuners vs MS, but let me know...
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Postby Loren » Sat Nov 03, 2018 4:53 pm

If you can pull a human readable timing advance table, that might be useful. Fuel, I can easily time with the wideband.
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Postby nathanwilliams617 » Mon Nov 05, 2018 11:04 am

Attached two files. The software shows a ton of tabs/buttons, but these two are from the "Main Spark Advance" section High Octane and Low Octane maps.

If this helps, let me know if you need others such as;
Cranking/start,
Idle Spark Advance,
Spark Correction based on AFR
And the list goes on...
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Postby blacksheep-1 » Mon Nov 05, 2018 11:27 am

I always wanted to take a S10 extended cab, and using a Olds Toronado or Caddy front drive setup, put a small block in the bed, the front of it would end up a bit under the back half of the cab, but you'd get great weight distribution and have an independent rear in the car.
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Postby Loren » Fri Nov 09, 2018 11:28 am

Nate, thanks for sharing that info! I haven't even had time to look at it, but I hope to soon.
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Postby nathanwilliams617 » Fri Nov 09, 2018 11:31 am

Loren wrote:Nate, thanks for sharing that info! I haven't even had time to look at it, but I hope to soon.
Np
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Postby Loren » Fri Nov 09, 2018 3:03 pm

I'm going to have to do some research to figure out how to convert "air mass" into something approximating "manifold pressure", and the table is upside down from how I'm used to seeing it. (low load is at the bottom with MS) But, this is really good info. I could pull the same from the tune on my stock ECU, but I honestly don't know if it's been messed with or not... and it only runs up to 5500 rpm.

Nate, go ahead and send me the rest of the maps when you get a chance. Even if I don't get "exact numbers" from it, it would be interesting to see the trends in how they change the timing for cranking, idle, and different conditions. Megasquirt handles it differently. Rather than separate tables for different conditions, you just have the main table, and then modifiers to it. (like cold advance, intake temp retard, etc)

I suppose I do have the option of using two tables. Could switch them based on throttle position or something. If it seemed necessary. Most people get by with just the standard MAP vs RPM timing table and a little retard based on IAT if the intake gets hot.

Anyhow... I like to study stuff like this because I know that the factory engineers spent a lot more time and resources on it than I'll ever be able to. Even with the mods done to my engine and being 6.2 liters rather than 5.3... this should be a good starting point.
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Postby Loren » Fri Nov 09, 2018 5:14 pm

Okay. So... a little bit of time when I should probably be doing something else, but felt like doing this instead.

I took Nate's "high octane" map and shoehorned it into MS. I probably didn't need to, but I opted to use my dual spark table option. The MS tables are 12x12. Nate's tables are 25x29. I wanted the RPM resolution, so I triggered my table change on RPM. Greater than 2800 rpm bumps to the second table.

And Nate's table showed everything from 5200-8000 rpm being mostly the same. So, I just made the last two columns in my table 5200 and 7000. :thumbwink:

And then I extrapolated. Figuring 100% airflow is about the same as 100% MAP, and 50% airflow is about the same as 50% MAP. It's not, but it was worth trying on a whim. I basically just dumped Nate's table in there and tried it.

Well, first I looked at it a little. And noticed right away that the areas of the timing table I'd been working on that I thought were "good" (the idle and mid-range areas from idle up to about 2200) were actually very close to the same. Within maybe 3-5 degrees.

The other thing I noticed was that from there, I was advancing timing a LOT... and the stock map is actually retarding A LOT. This would explain the CEL I keep getting for misfires!

After a bit of hacking, I took it out to the truck and gave it a try. I had to tweak the idle area to get it stable. It was idling okay, but the way the map tapers timing advance to nothing in the far corner, as the idle settled in, it pulled timing, and the idle speed dropped, and it pulled timing, and the idle speed dropped... and it just kept going until it got unstable. So, I just set that whole corner to 10 degrees to "catch" it. And I've currently dropped it to 8 degrees, where I have a nice idle at around 800 rpm.

After making that first change, then the idle would hang at around 1200. I took a few degrees of advance out of the area it was hanging in (a little too happy there, I guess), and rpm appropriately dropped down to the idle area. Curiously, I think this is why the truck always had an idle hang on the stock ECU.

That's all I changed. Then I turned on autotune, and went for a drive. It wasn't quite running right at first, MS was pulling a LOT of fuel. I guess my timing was so far off that it was dumping in a lot of fuel to compensate. As that started getting tuned in, it ran a little better. Much smoother.

But, it did have one comical problem. Every time I let off the gas and let the engine idle down (in gear or not), it would pop loudly through the exhaust! Very consistently. Every time. Only way I could prevent it was to sort of ride the throttle as the rev's fell.

This was because I copied one of the rows from the low-load area of Nate's table into the lowest row of my table. Now, the way MAF works, that row represented probably a "light cruising" area. A little bit of airflow. More than idle, but low load cruising. Because MS is using MAP, what I did was stuck a LOT of timing advance into the "overrun" area of the table. It's that part of the table that you never get to unless the engine is coasting down with zero load. All of that extra advance, plus almost no fuel... pop pop pop! Easily fixed by changing that offending area to 30 degrees for now.

Also noted that my CEL for misfires is all but gone. It came on a couple times here and there as I was tuning and hitting places in the table that were clearly not tuned right. But, otherwise, it stayed off. Definitely a good sign. (and, as mentioned, completely logical... I was timing this thing completely wrong!)

So, good experiment. Learned some things.

I still need to research the differences between MAF and MAP tuning a little bit... assuming anyone has ever discussed it. I'm sure I'll need to tweak this table a little bit.

Oh, and it's quite dead below about 1800 rpm. Thinking about how it works again... I took the timing from a high MAF, low RPM area (which they have set for VERY little advance) and I stuck it in the high MAP, low RPM area. The difference there is that you can have high MAP without having high airflow. High MAP just means you've opened the throttle! Doesn't mean anything's happening yet. So, when I give it the throttle, it's pulling GOBS of timing on the low end. I'll need to sort that out. But, mild throttle from 2k and up feels great. Very smooth. Definitely a step in the right direction.
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Postby Native » Fri Nov 09, 2018 6:16 pm

That's awesome. Hurray for Nate! Loren, too, I s'pose...
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Postby Loren » Sat Nov 10, 2018 3:05 am

Loren wrote:I'm going to have to do some research to figure out how to convert "air mass" into something approximating "manifold pressure"
Found a little bit about this. MAF is actually measuring air density, and can be used as such in tuning. But, the other way to do it, and I'm pretty sure this is what GM is doing, is to convert that to a "percentage of load". I think that's what they're doing because their table ranges from .02 to 1.20. And everything above .80 is exactly the same. So, no difference in timing once you're over 80% load.

MS uses MAP in the same way. kPa can be seen as "percent load", and is often referred to in that way. It's just sort of how it naturally works out. 100kPa just happens to be atmospheric pressure. So, WOT = 100kPa = 100% load.

So, my hunch that I ran with in testing was probably correct. Sort of. I think it works for the mid and upper ranges.
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Postby Loren » Fri Jan 04, 2019 2:23 pm

It is now January 4th. I've been telling myself I haven't driven the truck in about 3 weeks. In reality, I think it's been considerably longer than that.

The last time I drove it (whenever that was), I was still playing with the timing map. Unfortunately, I didn't take notes on what I did. I seem to remember building a map from scratch based on some info in the MS manual, and maybe morphing that with the logic found in Nate's timing map? I really don't remember.

But, I do remember that I came up with a "sensible" timing map that was very conservative, and ran "okay". And the last time I was driving/tuning, I was running autotune to sort the fuel... and incrementally increasing the whole timing table by 2 degrees at a time in search of appropriate power without pinging. Just sort of creeping up on it from the bottom.

After that last drive, I made a late-night round of changes to the tune. I was WAY rich with my priming, cranking and afterstart enrichments (flooding and/or running pig rich after starting). So, I dialed that stuff back quite a bit. Made another change to the timing map (who knows what?) and maybe some other stuff. Again, I didn't take notes.

And then... I never got back to it.

Cut to Tuesday. I decided to just try to drive the truck down to Steve's to pick up the DE car for a lesson. I had never written the above changes to the ECU, and it was cold, and the truck hadn't started in a month. Pretty sure it flooded. Didn't start, and ran the battery down.

Thursday, I put the battery on charge. And Friday (today), I went out and started it around noon just to verify that it still ran. And then after lunch, I wrote the new tune, and took it for another tuning drive.

Well, I don't know what I did or where my timing map is (it's still pretty conservative), but after a bit of driving around and autotuning, it's not bad at all! It's not making all of its power yet. But, it's running smoothly. I'll take it.

The idle isn't even bad. I'm using the adaptive timing advance to keep the idle speed in check. If it's above the target idle speed, it retards the timing (a lot) to bring it down. And if the idle dips, it advances timing to give it a little kick and keep it happy. Seems to be working pretty darned well. Absolutely no idle air control, but the beefy ass 383, just wants to idle... it doesn't care. Once it's running and stable, it will happily chug along at 750.

So, maybe this will inspire me to keep plugging away at it. A little more work on the timing. A little more autotuning. Maybe get into what Steve was playing with, and do some work on the acceleration enrichments. Definitely need to work on the start-up tuning. But, that's hard to do without some means of controlling airflow. Presently, I'm doing that with my foot on the throttle.

It's definitely running the best that it has since I installed the MS. I'll try to spend some more time with it next week.
Loren Williams - Loren @ Invisiblesun.org
The "Push Harder, Suck Less" philosophy explained:
Push Harder - Drive as close to the limit of your tires as possible.
Suck Less - Drive something resembling a proper racing line.
Joe Brannon
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Loren's V8 S10

Postby jbrannon7 » Fri Jan 04, 2019 4:01 pm

If I recall correctly, you are tuning this with a laptop. If so just do print screen and save as jpegs for documentation.

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