Table resolution and size

[hassmaschine]

I'm gonna give leaving things alone a big thumbs up. If you can't get your car running smoothly on 16x 30 or 30x 30 you've got other issues anyhow. I know I had no probs with just 16x16 fuel and spark when I was running the 8V N/A setup on my car and I'm sure I could do the same thing now that I have added 12 valves and 12psi boost.

Hope you have the opportunity to have your hands on 10 - 12,000 rpm motor with more than 35psi of boost and call it easy with 16x16. Plus you have about 1 - 2 hour of time to wrapped up on the dyno.

there areas where it's non linear (mostly where the torque curve increases and decreases), you just need to be mindful of where you are placing your RPM columns.

That is the time consuming part I was talking about. With big tables these are addressed in advance. During a tuning session what you should do is to tune the motor, not addressing problems. Time constraint contribute to hard thinking.

it's actually very simple if you are on a dyno. Take a baseline pull (which you have to do anyway), look at the shape of your torque curve - VE and torque are very closely related. so where torque is non-linear, that's where you should group your columns, and where torque is flat or sloping linearly, that's where you would space them out.

[Peter Florance]

it's actually very simple if you are on a dyno. Take a baseline pull (which you have to do anyway), look at the shape of your torque curve - VE and torque are very closely related. so where torque is non-linear, that's where you should group your columns, and where torque is flat or sloping linearly, that's where you would space them out.

With my previous disclaimers considered; I would assume this can be done at a reduced power level or boost level and yield similar results?

In the NA world, my fuel curves seem to have the same shape from load row to load row. So I should be able to identify those spots easily

[hassmaschine]

yeah, you just need a safe base map that has reasonable timing and fuel. It doesn't seem to change much with tuning as the shape of the torque curve is affected a lot more by physical engine characteristics than minor changes in tuning.

if I overlay the torque curve from my stock ECU, totally untuned, and one from MS2 that's fully tuned, they have the exact same shape, except one is shifted up because it's making more power (guess which one? )

[Gokart]

hassmachine: Thanks for the tips.
Just to dig you assistant; for a daily driven 30 psi (2bar) car, how do you think I should do it?
I just can't jump to the max boost and I need more resolution to the non boosted area.
From what I did, more resolution yields smoother ride. A spaced bin feels rough.
Anything above 14psi should be done with care.

[kpr]

heres one that maybe of interest. this is the worsted thing ive tuned. engine has large cams and individual throttles, its near un-tuneable below 2500rpm at wot. from around 3500rpm right through to 8500rpm afr is flat -+ .2 afr. running tps vs rpm (alhpa n) using 8 x 22. could trim out some load points without any issue. but wouldn't want to go too many less rpm points. a 16x 16 table may have issues. but is a non issue if can use a 2nd overlay map to trim where required.

screen cap of tune :

http://img.photobucket.com/albums/v178/ ... tune-1.jpg

this car now has a ms3, have managed get fairly good tune with the 16x16 table. took a little more messing around, studying the afr then moving the bins around to correct afr. rather than the link ecu, where i started with 500rpm increments and just dropped extra rpm points in at the rich or lean spots, till i ran out of spare rpm points.
agree that the way the tables are edited could improve on tuning time. but to be honest it didn't take too much longer to tune over my old ecu, considering i was still learning the software along the way

[tpsretard2]

the link G4 has fully adjustable load sites just like the megasquirt.

I have used a few of the new Link G4's they are VERY nice ecu's
If you are selling it cheep i would make an offer

[kpr]

haha, sorry the link is already installed in my other car. i like the way you can add or delete a row or column where required with the link. would be a nice feature if could be done on megasquirt, rather than only being able to move the row/column. no big deal though

[Gokart]

...... i like the way you can add or delete a row or column where required with the link. would be a nice feature if could be done on megasquirt, rather than only being able to move the row/column. no big deal though

So is Haltech and Autronics.

[tpsretard2]

motec and autronic were the first people to do it.

[muythaibxr]

We won't be adding the ability to add or remove rows/columns.

I would like to see the tuning software gain the ability to scale the table automatically when bins are moved.

Ken

[VolvoGuy50]

Not sure if this makes any sense, but for the sake of satisfying 16x16 haters, if you manage to run out of space on the first table, make use of the dual-table mode. There's a setting in TunerStudio which allows a second table to take over after a certain MAP reading has been reached. I'm not on my tuning laptop, so I'm not sure exactly where that option is. I *think* it's under boost control settings, but I'm 100% sure. I suspect the apocalypse has occurred if someone running an NA motor manages to run out of space on a 16x16 table.

[muythaibxr]

Yeah, that's what I've been suggesting for those who don't think 16x16 is enough... you can combine up to 4 tables for something like 30x30 (need a few rows/columns for blending).

I can't imagine anyone even on a turbo engine needing more than 16x16 if their bins are divided up well.

Ken

[VolvoGuy50]

I can't imagine anyone even on a turbo engine needing more than 16x16 if their bins are divided up well.

Yeah, maybe on some insane quad turbo V12 with 2 stage N2O boosted to 4 bar; but even then.

Just for lolz & giggles, I wonder how big the table that is used on the Bugatti Veyron is? If it's 16x16 or less; that should end this argument once and for all.

EDIT:
Just checked on my laptop. To expand the table after a pre-defined MAP pressure, just use normal tableswitch mode. Fuel > table switch/dual-fuel.

[kpr]

wouldn't it be easier to tune the 16x16 table. then if inadequate, (points too far apart in places, due to quickly changing ve) add a 2nd table and use to trim fuel, at required load & rpm points ?

turbo cars are easy. generally you wont run enough cam overlap for anything weird to happen. n/a with big cams and overlap, covering a large rpm range. is likely to have more issues, rpm wise. i doubt load points will ever be an issue with 16x16, even at high boost levels

[y8s]

wouldn't it be easier to tune the 16x16 table. then if inadequate, (points too far apart in places, due to quickly changing ve) add a 2nd table and use to trim fuel, at required load & rpm points ?

turbo cars are easy. generally you wont run enough cam overlap for anything weird to happen. n/a with big cams and overlap, covering a large rpm range. is likely to have more issues, rpm wise. i doubt load points will ever be an issue with 16x16, even at high boost levels

I have a turbo car with VVT. There's a region where I run a lot of overlap in the midrange and I had to move some rows around because the VE jumps about 15-20% from one RPM cell to the next. And they're only 300 RPM apart.

[hassmaschine]

as has already been posted in this thread a few times, there is already support for more than 16x16 resolution. How you accomplish this is up to you - I like using secondary load/additive as it acts more like one table rather than two seperate tables - but the result is the same.

I actually tried to go down to a 16x16 table - in some areas, I actually had too much resolution before. But the table went from 500-7500rpm, and even with well placed columns, I had some non-linear areas where I could not get the AFR where I wanted it. I ended up adding about 6 more columns (using secondary load). That gives me plenty of space if I ever build a motor that can go to 7900.

[muythaibxr]

wouldn't it be easier to tune the 16x16 table. then if inadequate, (points too far apart in places, due to quickly changing ve) add a 2nd table and use to trim fuel, at required load & rpm points ?

turbo cars are easy. generally you wont run enough cam overlap for anything weird to happen. n/a with big cams and overlap, covering a large rpm range. is likely to have more issues, rpm wise. i doubt load points will ever be an issue with 16x16, even at high boost levels

I have a turbo car with VVT. There's a region where I run a lot of overlap in the midrange and I had to move some rows around because the VE jumps about 15-20% from one RPM cell to the next. And they're only 300 RPM apart.

When we get PID control for VVT implemented (looking like this weekend) you'll probably be able to tune that out while in boost by removing the overlap when you go into boost.

Ken

[y8s]

I have a turbo car with VVT. There's a region where I run a lot of overlap in the midrange and I had to move some rows around because the VE jumps about 15-20% from one RPM cell to the next. And they're only 300 RPM apart.

When we get PID control for VVT implemented (looking like this weekend) you'll probably be able to tune that out while in boost by removing the overlap when you go into boost.

Ken

I wont want to... power curve doesn't seem to care about boost level much at all. I got best results with moderate overlap over a certain RPM range regardless of boost pressure. I did a few runs back to back with the VVT fixed at one value and also with the VVT tied to boost pressure (ie retard cam at 3 psi) and you can see the power drop like a stone when the cam retards as boost builds. opening the intake valve early in boost in the midrange is worth about 45 ft lbs at 3500 rpm.

You're right though in that I will likely be able to smooth out power onset (ie increase power) just before the VE ramps up steeply.

[VolvoGuy50]

Well, I guess I'm gonna have to eat my own words.

16x16 isn't cutting it for my setup. My turbo covers such a large power band and spools slowly enough that I needed to split it up between 2 tables. I can't blend it well enough with a turbo this large. I've got it switching to the second table at 0.5 bar of boost and the second table takes it up to 2 bar with some extra fluff at the top in case of boost spikes.

So I guess in SOME limited cases, duel tables might be needed to get a smooth map...but unless you're running a semi-truck turbo like me, I doubt that will ever come about.

[K2e2vin]

That would be nothing new, at least for many turbocharged Hondas. Their stock ECU is already capable of dual 20x10 maps(RPMxLoad), but many of the guys boosting switch to at least a 20x16(up to 20x24) when boosting. Most of the cells are dedicated to load which helps fine tune idle and boost build-up for large turbos. A similar engine, the 4G63, I've seen them go to something like a single 25x30 map(up from ~15x20 stock?); and of course most of the cells are towards lower RPM and mid-boost.