EAE tuning advise

[16vboost]

I've made it my goal to get my engine running as smoothly as possible. For this to happen I really think I need to turn on eae. When I first turned it on it resulted in the engine running like crap and almost instantly turning off. Fair enough, I hadn't read anything about it. Now I have.

So before turning it on again, I did all the prerequisites. I went from 2 squirts alternating to 4 (now idles at 1.7ms but it's fine). I got my injector dead times as close as I could by changing between 2 and 4 squirts back and fourth. I have tuned the crap out of my VE table (I agree that this is fundamental). So now when I enable EAE, the car is still driveable. I've started tuning it based on what I understand, but I am at a point where I feel I can only make things worse.

The basic eae tuning instructions consist of an explanation of how the graphs work, and the procedure is 'make adjustments until you get the desired outcome'. I'm trying to get a little more detail here. I'm trying to tune the mid-range RPMs (around 3k first). The graph shows me slowly rolling on the throttle, holding for a while so wall fuel stabilizes, and then rolling off. I pull the e-brake to keep RPM constant. I then look at the graph and scratch my head. Where do I go from here. I know how adhere to walls and sucked from walls work fundamentally, but I don't know how to alter the curves based on my graph. I still get a lean spike when I get on the throttle and a rich dip when I let off. Lowering sucked from walls or raising adhere to walls should help with the lean dip but I don't know where in the curves to modify the values. I've been trying to look at the MAP where the spikes occur and adjusting the graphs there, but the map is changing fast and the AFR is delayed slightly. Any tips?



Thanks,
-Alex

[E4ODnut]

Why not forget about acceleration enrichment until you are completely happy with your steady state tune? If you are easy on the throttle, you don't need any acceleration enrichment. Get the steady state dialed in first, then start punching the throttle and work from there. If your driving style is conservative, you won't need much. If you want to be able to really jump on things, you will have to do some work

Sorry I can't be more specific.

[16vboost]

I have tuned the crap out of my VE table (I agree that this is fundamental)

Steady state tune is spot on. The log shows me rolling on and off the throttle. No stomps (yet).

More fundamentally, I'd like to tune the engine so that anyone can drive it regardless of their driving style or knowledge of the engine's quirks. Believe me, before megasquirt I had to rev this engine to 2500 RPM just to slip off the clutch to get going in a casual manner. The increase in low end torque over the stock CIS-E now lets me drive it like a normal person. I'm trying to do the same for gear shifts with EAE.

I'm just looking for more detailed information on how to tune. I'm sure there is a methodical approach out there.

-Alex

[muythaibxr]

I would start by increasing added to walls at the top kPa that you hit, then smooth the rest of the curve down to the kPa you started at. Often I have found that once you get the throttle press behavior right, throttle lift cleans up on its own.

Ken

[pit_celica]

Here is a usefull post that I use when I don't know remember how EAE is working :

http://www.msextra.com/forums/viewtopic ... 66#p185966

Taken from this thread :

http://www.msextra.com/forums/viewtopic ... 8&start=20

Basically, keep the engine at 3000 RPM and do some small accel/decel during the same MAP range. Exemple : Cruise at 3000 RPM at 40 kPa. Press throttle to go to 60 kPa, try to hold 60 kPa for a few second. Then, depress throttle to decel from 60 kPa back to the 40 kPa.

If you are seeing lean on accel : increase added to walls or decrease sucked from walls.
If you are seeing rich on accel : decrease added to walls or increase sucked from walls.
If you are seeing lean on decel : increase added to walls or decrease sucked from walls.
If you are seeing rich on decel : decrease added to walls or increase sucked from walls.

Because you are trying to stay at a constant RPM, do not touch the ATW vs RPM and SFW vs RPM curves, only the ATW vs MAP and SFW vs MAP. Repeat at the same 3000 RPM for different MAP range (ex : 25-40, 60-70, 80-100). From my experience, the 30-60 kPa region is the most critical. On boosted application, over 100 kPa do not make a lot of difference, so I do not car about them. My boost ins't coming really fast anyway.

The next step is to do the same test for a constant MAP range, but on a different RPM value (ex : 2000, 2500, 3500 etc).

Good luck!

Sam

[16vboost]

Thanks Sam. I've been trying this approach and it seems to be working. I'll post my results soon.

Ken, I wasn't sure what you meant by the "top kPa that I hit". Did you mean once I reach full throttle, at the end of the lean spike, or just before I let off the throttle? Either way, I'm interpreting Sam's advise to mean that I start at a given MAP, then open the throttle just enough to get to a higher MAP. I then turn up the added to walls at this higher MAP and smooth the curve to the lowest MAP as you said.

Wouldn't it be great if you could over-lay the ATW and SFW curves on the same graph? With different scales of course. This way you could really visualize the difference between them which is what drives more EAE correction. For now it's fine though.

-Alex

[swera]

Yes, this is what I see too. I find it interesting that I have about full point difference between the 351s and the other two engines. I don't know if the WBs are accurate or not. It really doesn't matter in the big picture, because it's only relevant to the particular engines, but it puzzles me.

The 351s are in a boat, so tuning is a bit easier, almost like a dyno. What I do find on them is that there doesn't seem to be much difference in power between about 11.8 and about 12.5. It drops a bit to 13:1 then falls of quite dramatically. I have to be about 11:1 or less before I start to lose power on the rich side, and then it's not all that much.

[nathanhardy]

Subscribed

[strain]

Subscribed

+1

[16vboost]

Oh I pretty much solved my EAE problems. The secret is to get it working generally as you'd expect and then tune throttle stabs with time-based AE. I pretty much use EAE to cut fuel between gears as needed to keep the engine from going rich. Time based AE (together with EAE) is tuned for the throttle stabs. I ended up reversing the SOW curve so that lower pressures mean more is sucked and higher pressures mean less is sucked but I've been told that not everyone needs to do this and most get good results with the default shapes.

-Alex

[lagos]

Oh I pretty much solved my EAE problems. The secret is to get it working generally as you'd expect and then tune throttle stabs with time-based AE. I pretty much use EAE to cut fuel between gears as needed to keep the engine from going rich. Time based AE (together with EAE) is tuned for the throttle stabs. I ended up reversing the SOW curve so that lower pressures mean more is sucked and higher pressures mean less is sucked but I've been told that not everyone needs to do this and most get good results with the default shapes.

-Alex

can you post your msq?

[16vboost]

Here's my MSQ. If I really get picky, I can improve low-RPM EAE. I might some day or just leave it as the car feels and drives great.

-Alex

[lagos]

Thanks for sharing! What engine is this for? Looks similar to my 2nd gen 3sgte DIYPNP setup.

[16vboost]

It's a VW 1.8 16V (engine code PL). But it has a custom short runner intake with dodge SRT4 injectors. So the spray pattern and angle of the injectors may or may not be ideal.

-Alex

[everlast]

Bump from the past, I know, but I have a very specific question about this post.

In the example, you'd be cruising at 40 kPa and press throttle to go to 60 kPa. Let's say you're rich in this example. This post says:
"If you are seeing rich on accel : decrease added to walls or increase sucked from walls."

What range in the EAE map would I change? At the 60kPa point, or at the 40 kPa point?

OR would I do a little of both:

- Decrease added to walls at 40 kPa (because there's less fuel sticking to the walls than the model thinks)
- Increase sucked from walls at 60 kPa (because more fuel is coming off the walls and going rich)

REALLY working on my EAE because my car **&^@* stinks too much to drive.

Here is a usefull post that I use when I don't know remember how EAE is working :

http://www.msextra.com/forums/viewtopic ... 66#p185966

Taken from this thread :

http://www.msextra.com/forums/viewtopic ... 8&start=20

Basically, keep the engine at 3000 RPM and do some small accel/decel during the same MAP range. Exemple : Cruise at 3000 RPM at 40 kPa. Press throttle to go to 60 kPa, try to hold 60 kPa for a few second. Then, depress throttle to decel from 60 kPa back to the 40 kPa.

If you are seeing lean on accel : increase added to walls or decrease sucked from walls.
If you are seeing rich on accel : decrease added to walls or increase sucked from walls.
If you are seeing lean on decel : increase added to walls or decrease sucked from walls.
If you are seeing rich on decel : decrease added to walls or increase sucked from walls.

Because you are trying to stay at a constant RPM, do not touch the ATW vs RPM and SFW vs RPM curves, only the ATW vs MAP and SFW vs MAP. Repeat at the same 3000 RPM for different MAP range (ex : 25-40, 60-70, 80-100). From my experience, the 30-60 kPa region is the most critical. On boosted application, over 100 kPa do not make a lot of difference, so I do not car about them. My boost ins't coming really fast anyway.

The next step is to do the same test for a constant MAP range, but on a different RPM value (ex : 2000, 2500, 3500 etc).

Good luck!

Sam

[muythaibxr]

Make the changes across the whole affected range, then smooth with the surrounding area.

[everlast]

Thank you!