Cascade Crew

[Alphius]

Those of you who do tuning, could I ask to see your spark maps for comparison to mine? Even a stock spark map could be helpful for the information. Fuel maps are easy with the wideband, but spark is hard to tune on the street. It seems like fumbling around in the dark looking for max torque without hurting my motor.



I have one map from someone else Megasquirted I think I'll try, but it seems a little conservative, but very smooth. It's from a bone stock 70's 350 with a TBI on top:



Then there's my map, which seems to run good and not detonate, but also looks uglier than sin :



Any tips or pointers? Should I use the new, smooth pretty map or my old one that seems like it's all over the place?

You know, after looking at this post and my 3D maps, I kow at least one improvement to my table would be for sure smoothing the upper kPa range, so it doesn't spike at 100 kPa. Don't know what I was thinking with the tuning then, but it looks like I just focused on getting 100 kPa to max timing with no knock and ignored the 90 kPa and down bins. I haven't even looked at timing in quite a bit, I've been focusing on VE recently.

If you have a map to share, even from a stock ECU or another aftermarket ECU, I'd really appreciate it.

By the way, my motor is about 9.3:1 compression with flattop pistons and mildly ported smog era truck heads. Don't rib me too much about the heads, an upgrade is in the works.

[aaron_sK]

This table sucks, I'll be the first to admit it. It's what I was running in the IROC when I sold it. It needs much more at cruise, and at high rpm WOT. Looking at it now it's obvious I was leaving quite a lot on the table.

It's not the one I was running at dyno. I can't find that file but it was a little more aggressive.

[Alphius]

[Schultzy89GTA]

Did you add a little 'juice pack' or is that future plans?


-Schultzy

[83Z28BlackBetty]

I'm going to be much more interested in this stuff in about a month. I'm working on switching over to a EFI setup based on a modded TBI unit.

A little off topic Gabe, What did it take to run MegaSquirt? is it a new ECM or is there much more that needs to be done?

~JAKE

[Alphius]

[d00012]

There's also the EBL flash that works well with TBI. Basically, it's plug'n'play. It's pricier and easier than the MS. $350. If you're swapping to TBI, you will need the tbi harness and specify what year/vehicle it came from.

I'll be getting one for the 3.4 once it's all built.

[Alphius]

EBL looks really cool. If I had a car to run it on and some extra money I'd love to try it out. For me, MS was the way to go, but it's definitely not for everyone.

One reason I love MS is the flexibility. For example, someday not too far away I want to convert my engine to distributorless ignition with wasted spark, and I can do that with MS.

[83Z28BlackBetty]

Thats awesome! For now I have a tbi harness and computer to get it on the road and running, but am looking for something with a little more bells and whistles for the future. And every time you post something else MS does, it makes me VERY curious.

Oh you know you want to make a trip down here sometime! I'll tell you it does make for one EPIC road trip. with plenty of open road to test those WOT and top speed runs...

[Twilightoptics]

You'll want to tune real quick Jake.

Did you get a 7747 ECM with a 350 setup?

You definitely don't want 305 tbi stuff on there. (yours is 350 right?)

Map based EFI is less forgiving of non stock calibrations than MAF setups.

EBL is the way to go with TBI. The stock TBI "live" data stream is slower than 70's PONG. It's rediculous. You can't really see O2 trends or glitches.

I'll fire up my laptop this weekend and get you a screenshot of my timing.

I'm running about 45 at cruise 1700-2400 in the 40-60kpa range.

Basically take your original map, tweak it, and add 10degrees everywhere but 94-100kpa. I don't recall what heads you have, if they are a vortec heart shaped chamber 34degrees wot at 3000rpm sustained is the way to go. I tuned my HSR on the dyno with 30-32-34-36-38 and noticed no noticable gains or decreases so I chose 34 as a good number.

[Alphius]

[83Z28BlackBetty]

HAHAHA thanks Gabe, I definitely like the DIY stuff for sure, but the more i read about the EBL the more i like it. With a 2 bar MAP sensor it car control boost, N2O, and the tune on the fly flash stuff sounds sick.

But i'm getting WAY ahead of myself here... For now i'm just swapping in stock TBI to get it to run right. its from a 91 305, which should work fine in stock form on my 305 for now. But you are right Paul, i want to start tuning already!

~JAKE

[83Z28BlackBetty]

so... to revive an old thread. I have started tuning now an am starting to figure out these spark tables. My original table in the chip i've been using was SO CONSERVATIVE. It was like 19* at WOT and 24 at cruize?! wtf. So the past few days i've been messing with that and it has helped a ton! but now i have to redo all my fueling because i'm super lean now...

Aaron, what else would you change about your graph, because i'm totally copying it. HAHA

~JAKE

[Dewey316]

Just make sure you zero out the other spark adder tables, and only use the main table.

The only exception to that, is the coolant temp spark modifiers, i would leave those to pull some timing out if you start to run hot, just as a saftey mechanism.

And, of course, watch the knock counts closely as you make the timing changes.

[91RSVert]

Mine has so many different tables depending on what "mode" its in, I dont know which one is the one running mine. Mine is obd2 also, so dont know if it would help?

[aaron_sK]

[Alphius]

Very good tips Aaron. I will proceed to echo your sentiments.

I have smogger truck heads and I run 36 degrees at full throttle all in by 2800. Any less and my butt-o-meter complains, too much more and I get a slight detonation rattle sometimes.

For idle make sure you set all the cells around where you idle to the same value or it will hunt an idle pretty bad at times. Like Aaron said.

Under cruise, try to set it as advanced as you can without feeling it miss or buck. And watch your knock sensor counts closely. Smooth the table down everywhere outside of cruise. It's been a while since I looked at my spark map I ended up with (not posted in the thread), but here's some values:

36 all in by 2800 for full load
38 under cruise, but there's room for up to 42-44 I think
22ish at idle

[aaron_sK]

I ran as high as 45* at cruise for the trip to cows '08. It did surge though, so I dialed it back.

I found the L98 really liked 24* at idle. That is all about cam and compression though. And transmission. Idle is not as important for an auto car. With a stick you need the engine to have some balls at around 800rpm so you can engage the clutch. An auto car has the advantage of torque multiplication at that point.

BTW, that one change to the idle timing made passing idle CO emissions in that car a LOT easier. Which is weird because usually the opposite is true.

[Twilightoptics]

Less timing helps emissions.

I run 28 at idle, 34 WOT, 41 cruise

A good modern combustion chamber and 32-34 is all you need. Smogger stuff should be as much as possible without detonation.

Jake, others touched on the important part. Research and figure out how to make all other tables (save hot temp) set to not affect the main table.