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-   -   Timing un-retard... How far can we go? (https://www.miataturbo.net/methanol-water-injection-22/timing-un-retard-how-far-can-we-go-7419/)

Joe Perez 02-12-2007 07:31 PM

Timing un-retard... How far can we go?
 
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In the month or so since I got my DO kit installed and working I've more or less sorted out the fuel situation and have started to focus on the timing. Thus far I've just been incrementally adding equal amounts of advance (or reducing the retard) across the whole boosted area of my map, which itself is based on BGRacer's work.

Thus far I've added six degrees back into the lower half of my timing map, and no discernable ping as of yet. I'll probably try another two degrees this afternoon on the way home. Does anybody have a good feeling for what sort of limit on ignition advance (or un-retard) I should safely expect to reach?

I've attached a screenshot of my current IGN map. (remember, these are relative advance/retard numbers, not actual timing) This is on a stock (10 BTDC) base timing, intercooled 1.6 Greddy, with D.O. injection. Currently reaching about 11PSI boost maximum. AFR is typically running an indicated 12.5 to 13.0, though I believe it's actually just a bit richer than this (based on observing the WBO2 as I switched the WI on and off manually). Fuel is California 91 (R+M/2) octane. I'm injecting about 50% Methanol and water.

boostinsteve 02-12-2007 08:39 PM

I think that you can add in a lot more timing than what you have now. I am at 8-9psi, and I am only pulling 3 degrees from a base of 12 degrees. I have absolutely no knock either, my only problem is that the fueling is a little lean, and the clutch is slipping.

Joe Perez 02-13-2007 11:33 AM

Well, added another two degrees in last night, and still no pinging. This morning I also increased the boost to 12PSI, with initial surges to 14. (Yes, even the fancy TurboXS HPBC permits spikes...)

I'm now at +8 degrees vs. my old ignition timing map, which was right on the verge of detonation. I don't know why, but my engine loves to ping. And yes, I verified that the crank pulley hasn't slipped. I know there's a point of diminishing returns on ignition advance, not sure where it is for my engine yet. Add that to the list of things to figure out on the dyno...

So I guess this is one very happy DevilsOwn customer so far. :bigtu:

Now all I need is a bigger tank. The washer bottle ain't cutting it.

magnamx-5 02-13-2007 12:07 PM

Awsome the results keep on pouring in great work joe.

rockdoc 02-13-2007 12:41 PM

Joe

your running similar boost to mine ,and youve seen my map:eek:
So maybe you can go a bit more, i was happy to push it as far as i could -since i had a decent Knock monitoring/sensing system and my CR ratio is i think a little lower than yours.

magnamx-5 02-13-2007 12:43 PM

i should hope he can match a 12 psi m45 at least. we shall see.

Al Hounos 02-13-2007 12:52 PM

How do I read that timing map? Does it say -1deg of timing at 12psi at 4500rpm???

rockdoc 02-13-2007 12:54 PM

yeh,for sure itll be a good comparison:bigtu:

Joe Perez 02-13-2007 12:57 PM


Originally Posted by Al Hounos (Post 82308)
How do I read that timing map? Does it say -1deg of timing at 12psi at 4500rpm???

You're talking about mine? Those are whole degree increments, so it'd be -10 degrees at 11.4 PSI at 4500 RPM.

Joe Perez 02-13-2007 12:58 PM


Originally Posted by rockdoc (Post 82300)
Joe

your running similar boost to mine ,and youve seen my map

Actually, I haven't seen your map. I think you described it to me, but I couldn't find a plot showing the map itself. Did I miss something?

rockdoc 02-13-2007 01:05 PM


Originally Posted by Joe Perez (Post 82315)
Actually, I haven't seen your map. I think you described it to me, but I couldn't find a plot showing the map itself. Did I miss something?

oh?- lemme go check my messages/email - i was sure you asked and i sent my timing map, gimme a mo:)

bripab007 02-13-2007 01:06 PM

Al, I don't see a single "-1" anywhere in the 4500 RPM column, so I'm not sure wtf you're talking about :D

He's running a piggyback, so I believe this chart shows the advance or retard of the stock total timing table (base timing plus advance). If his base timing is 10°, his stock ECU might add ~17° advance at, say, 4500 RPM, for a total timing of 27°, then his e-Manage is pulling ~10° at 11.5 PSI, for a total of 17°.

That's what the graph looks like to me.

Al Hounos 02-13-2007 01:11 PM

Ah ok. Too much math. 17 sounds pretty damn advanced for the peak torque area. Mine runs 12 through there I believe.

rockdoc 02-13-2007 01:12 PM


Originally Posted by rockdoc (Post 82322)
oh?- lemme go check my messages/email - i was sure you asked and i sent my timing map, gimme a mo:)

sent it to ya on 26th jan- you lost it :)

bripab007 02-13-2007 01:16 PM

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Joe, I have Emilio's (of 949Racing fame) e-Manage timing map which shows non-intercooled timing and water-injection timing, both at 8 PSI and 10° base on a '99 motor...not sure what octane gas, but I would guess it's either 91, 94 or a mixture of both to achieve ~93.

He's pulling less timing than you non-intercooled, FWIW.

Also, I'm pulling ~5.5-6° of timing, intercooled, at ~8 PSI, FWTW.

bripab007 02-13-2007 01:21 PM

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Al, here's the stock 1.6L ECU timing advance (add 10° base to get the total timing).

Joe Perez 02-13-2007 01:54 PM


Originally Posted by Brian (Post 82324)
He's running a piggyback, so I believe this chart shows the advance or retard of the stock total timing table (base timing plus advance). If his base timing is 10°, his stock ECU might add ~17° advance at, say, 4500 RPM, for a total timing of 27°, then his e-Manage is pulling ~10° at 11.5 PSI, for a total of 17°.

We have a winner. :bigtu:

Those numbers are advance or retard done to whatever the stock ECU is putting out. The data we have for the stock timing is one-dimensional (advance vs. RPM) whereas the stock ECU takes load into account, by comparing airflow to RPM. And since I don't have the CAS hooked up, it's impossible for me to say what the actual ignition timing is in the less-then-boosted areas. But that's a more or less academic problem, not a practical limitation...

BTW- *VERY* nice chart, Brian.

Joe Perez 02-13-2007 02:17 PM


Originally Posted by rockdoc (Post 82327)
sent it to ya on 26th jan- you lost it :)

Thanks, Rock. Don't know where I put that...

bripab007 02-13-2007 07:10 PM

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Originally Posted by Joe Perez (Post 82355)
The data we have for the stock timing is one-dimensional (advance vs. RPM) whereas the stock ECU takes load into account, by comparing airflow to RPM.

Oh, sorry, you mean like this? :bigtu:

EDIT: Changed graph to 2D and format to .PDF for consistency and ease of use.

Joe Perez 02-13-2007 07:36 PM

Ladies and Gentlemen, I present the Smartass of the Year Award:

Originally Posted by Brian (Post 82509)
Oh, sorry, you mean like this? :bigtu:

Yeah, pretty much like that. ;)

Seriously, I'm amazed by this wealth of information. And also that there's not a sticky labeled "Everything Brian knows for some mysterious reason but hasn't shared with the rest of us until just recently."

Would you happen to have the original table that generated that chart?

bripab007 02-13-2007 08:09 PM

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Dude, I've posted the table in threads from like a year or two ago (my old screen name, bripab007, became glitchy, so I was forced to create a new one earlier this year). I got the original table off M.net way back when I first joined over there. In fact, the original Excel file I have used to show the raw hex data output from the stock ECU, but it stopped displaying correctly somewhere along the way. I recall the person who posted the table found it on some Japanese site that likely no longer exists.

Anyhow, here's the table that I used to generate the graph (I know the graph was fugly and a little hard to read, but I put it together in the few minutes I had before dinner, so cut me some slack :)).

Also went back and re-did the graph in 2D, converted to .PDF and re-uploaded to the previous post ;)

Joe Perez 02-13-2007 09:54 PM

I guess I'm just about as retarded as my timing then. Somehow I've managed never to open that before. But then I lost the map that Rock sent me too... :nuts:

bripab007 02-13-2007 10:46 PM

It's cool, dude. I've seen so many of the same questions asked and the same answers given in the same threads over the years that I could easily be thinking about something I posted over on M.net.

magnamx-5 02-14-2007 09:11 AM

for real this stuff goes around and around everytime we get a noob. Ive never seen those maps before either brian, or i dont remember seeing them. do you have a key for the colors, on the lines, to designate load or, whatever the color indicates.

bripab007 02-14-2007 09:51 AM

I found an old thread on this forum where I posted a link to the original Excel file, only it was hosted on a site that no longer exists, so maybe that's why nobody remembers seeing it :)

Magna, it should be pretty obvious when viewing the chart that the higher the load number, the less timing is advanced by the ECU (e.g. load 15, which is light purple in the key, represent WOT, the highest load registered by the AFM). The ECU also uses the same timing map for some of the loads, that's why several are overlapping and not visible on the graph, but you can clearly see that in the original table.

magnamx-5 02-14-2007 09:53 AM

ok i just wanted to be sure. before i made any assumptions on it.

bripab007 02-14-2007 10:20 AM

Well what did you think, that the lowest load would be adding the least amount of advance? Guess you didn't notice that the S15 load also matches that of the previous WOT vs. RPM graph?

Just givin' ya a hard time, Magna ;)

magnamx-5 02-14-2007 10:49 AM

geez oh well it isnt as if you dont get much practice. :) i understand, Its cool. Anyone who can't laugh at himself shouldn't be aloud(alowed) to laugh at others. :bigtu:

bripab007 02-14-2007 02:19 PM

So, Joe, are you gonna add in a bunch more timing or what? Magna was running as much (slightly more?) boost as you with no intercooler and stock timing! :eek:

Ben 02-14-2007 03:03 PM


Originally Posted by Brian (Post 82790)
So, Joe, are you gonna add in a bunch more timing or what? Magna was running as much (slightly more?) boost as you with no intercooler and stock timing! :eek:

Yeah and look how that worked out for him :gay:

The problem with tuning for WI is that you're fucked if you run out of water

Joe Perez 02-14-2007 03:37 PM


Originally Posted by Ben (Post 82802)
The problem with tuning for WI is that you're fucked if you run out of water

True, but I'm working on a solution for that too. It's not elegant.

It's hard to tell over the noise from my transmission, but I think I might have heard just a touch of ping this morning. I'm going to advane it a bit more to see if it gets worse.

bripab007 02-14-2007 04:08 PM

I doubt it was ping since you're running less advance than I am, and I don't have water injection.

You should be able to run a bunch more timing advance.

Joe Perez 02-21-2007 10:26 PM


Originally Posted by Brian (Post 82832)
I doubt it was ping since you're running less advance than I am, and I don't have water injection.

Well, you were right- I found the source of the "ping" this afternoon. My homebrew heatshield (which is presently in its third iteration) cracked again and was banging against its supporting post. :vash: Looks like I've got some more work to do...


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