Wolfe

iTrader: (1)

Is anyone running just the Cobb Stage 1 map?

Do you like it?

I'm also concerned with running Catless. The Cobb Notes say it could cause the car to run too lean.

Also, The Cobb Forums have been taken down so I am unsure of where I can find the AccessTuner program (all the links to it were through their forums) I have a program just called AccessPort Manager. Anyone use this?

I am doing a lot of reading, but its still a lot to get my head around how to use the thing.

Edit: This is turning into a really informative thread! Thanks all for the replies and help!

no-coast-punk

Accesstuner Race Request Form

Fill out that form and wait a few hours.

Custom tunes are always a good thing.

The OTS stage 1 map is night and day in terms of response and smooth running.

If you aren't in a position to get a custom dyno tune, or feeling comfortable enough to do a road tune yourself, I wouldn't even worry about a cat delete. You are talking single digit HP gains.

Wolfe

iTrader: (1)

Alright, I'm running the Stage 1 map right now. I'm gonna go do some data logging later when it cools off a little outside (100f current).

Engine running smooth. Feels good. Would be great if someone with experience could look over the logs later and tell me if I'm within safe limits etc.

yomomspimp06

it's been a while since I've played with my AP, but if you get the logs up tonight I'll take a look.

Wolfe

iTrader: (1)

I did not get any proper logs. What are the things I should be logging? and the proper order to do it? This is a half ***'d 2nd gear pull. not even WOT. I'm just seeing how it works. Will get some proper logs as I learn more. Idle AFR is 15.0 ish and normal driving around 3k rpm is about 14.7 ish.

EviLStewie

10 Second Idle log
Cruise log in Open Loop
WOT in 3rd or 4th gear, this can be tricky depending on the roads in your area.

You need to add LTFT to your log

Those 14.11 afr's are something you'll want to watch if you were WOT but it's only a part throttle log so generally speaking it looks pretty good. IMO

Z0oMzo0m

iTrader: (4)

Lower your fan temps. :-)

ableobject

Is this going to become a tuning thread? If so I'm game ... I'd love to learn info on tuning.. Got my AP about 2 mo back.

Z0oMzo0m

iTrader: (4)

doubt it will be a tuning thread. lol. no one teaches and tunes for free lol. you will get the basic changes if your lucky

no-coast-punk

I've done lots of (hundreds of cars) AP tuning on non-Mazda platforms. Nothing is that different, outside of some of the ignition timing foibles due to the rotaryness. I'm happy to share everything I know.

The big remote tuner in this community seems to be MM. That guy was a complete **** head to me when I was ordering my AP. If I can take away a bit of his business, I'm more than happy to do it.

I got out of the tuning game long ago. I'm not here to make money.

First things first.

Only log the bare minimum. The serial bus only has so much bandwidth. The fewer variables logged, the faster your update rates.

At this point, all you are really concerned with is your STFT (Short Term Fuel Trim), RPM, Calc Load and Lambda.

If you have a stock intake (which you really should) leave the MAF cal alone. Mazda spent a **** ton of time developing that particular map.

The thing you want to start manipulating is your "Fuel VE" table.

You are looking at your STFT at a given calc. load and RPM.

If you look at your logs you will see a spot at ~4600 RPM (from your log) with a calc load of ~65. Look at your STFT. It's currently at 10.

The basics of what your ECU is doing is this:

It is looking at sensor inputs to see how much air is flowing into the engine. Estimating what the engines volumetric efficiency is to guess how much of that air is actually entering the combustion chamber. Injecting the amount of fuel needed to reach a given AFR specified in the target tables. After the fact, comparing what the O2 sensor is seeing as a result of the combustion.

Your STFT of 10% means that O2 sensor is seeing a mixture that is 10% leaner than the target AFR. It will add 10% more fuel to try and reach that AFR the next time around.

Since this is all happening after the fact, and the ECU's predictions are 10% off, it means that fueling is never consistent. This leads to weird throttle hiccups. It's like trying to keep your car between the lanes only using the rear view mirror. The important stuff already happened.

So what you want to do is to increase the value that particular load cell (closest you can find to 4500 RPM and 65 calc load) in the VE table by 10%. This is telling the ECU that the engine is 10% more efficient at inhaling air in that load cell. This means the ECU will inject about 10% more fuel.

When you are changing cells in the VE table, never change a cell in isolation unless it's a very small change. You want to blend any changes in with the surrounding cells.

So if you make your 10% change @ 4500 and 65, make a 5% change in each cell that touches it. Airflow doesn't make radical changes from one cell to another. Your mapping should reflect this.

Get your closed loop VE stuff as close as possible. This is where fuel economy and responsiveness comes from.

Once you get that dialed in, we'll move onto open loop stuff.

ableobject

Awesome, awesome, awesome!!! Thank you, for taking the time to type all that and, share your knowledge. I know there is nothing like hands on but, this is GREAT. Even if I don't get around to actually tuning myself (as I gotten tuning when i bought my AP) ill know the behind the scenes stuff. Cheers and Once again thank you

Wolfe

iTrader: (1)

no-coast-punk, there are too many things to thank you for right there. Thats an awesome explanation of whats going on. It makes sense. However, forgive my ignorance, I do not know what you mean by closed loop and open loop.
Also, would it be alright to go do logs on the dyno? I mean a 3rd/4th gear WOT for however long might be hard to do around here. How long should I go for on my pulls?

I will go out and get these later today. Yea I left throttle position on so you all could see when WOT.

I do have a stock intake. The only mods I have that would affect the logs are a mazsport midpipe and a greddy SE catback. I know the stage 1 is set up for catbacks, so I'm only a little worried about the midpipe.

Thanks a bunch for the responses guys.

Junkman 6394226

So THAT'S what fuel VE is? Awesome.

Also, Wolfe, this PDF might help you. Basically a bit of a manual for the RaceTuner. I'm working on a custom map as well, happy tuning!

no-coast-punk

Closed loop means that the ECU is using the oxygen sensor feedback as a reference for how it delivers fueling.

Closed loop operation happens during periods of low load/lower RPM cruising.

Open loop happens above a certain RPM/load value (those values can be found in all of the "Exit X" tables under the closed loop heading in the AP software). Under heavy loads/high RPM driving, things are happening too fast for the O2 sensor to be a reliable input. During open loop, the ECU sort of looks at the average of all the closed loop fuel trims and makes a guess as to a correction. (as an engine wears, its airflow properties change, this is why we have to bother with all of this 02 sensor feedback nonsense in the first place, as opposed to a one size fits all map)

This is why it's important to get the closed loop fueling dead bang on first. Not only does it make the car much more pleasant to drive, it makes it much easier to get the open loop fueling dialed in. Without good closed loop mapping, you will be all over the place in open loop.

Like I said, we'll talk about open loop adjustments once you get to that point. It involves several other tables. I don't want to overwhelm you with information.

As is, your car looks safe, just very rich. Some decent power can be freed up eventually by correcting this.

EviLStewie

Interesting.
All the other threads I've read on the topic use Maf Scaling.

The general idea is not all Maf sensor are equal.
I've also seen somewhere the same argument you use for the Maf Scale used with the Fuel Ve table. That the engineers spent a lot of money on developing that table and the Maf sensors are off between any given sensor.

Oh well there's plenty of ways to skin a cat.
Good read

EviLStewie

Question:
Couldn't this +10% STFT be cause from pressing the accelerator peddle?
(Tip-in?)

If you follow the Accelerator Peddle column you can see the OP is slowly depressing the go button.

Can road conditions cause STFT variances?
Like dips and hills etc?

Wolfe

iTrader: (1)

Ok. Thanks Junkman, I will read over that. looks good.

I will go out and do the Idle log, and closed loop. Should I log idle when cold as well?
I will take the car out on a nice flat straight road and do some 3rd& 4th gear 2,800 - 3,000 RPM for about 10-15 seconds(?)
I will add Lambda and LTFT to the log.
And get rid of Coolant Temp, Intake Temp, and Ign Tim Lead.
As a side note, remember that I am currently in Utah where the elevation is about 4500ft (elev of local airport)

EviLStewie

Punk is being nice enough to help you out with his method of doing things.
I wouldn't worry about the LTFT data he doesn't use it.
Keep the log data as minimalistic as possible to increase sample rate.


I don't know about Punk but I only do idle logs when the car is up to temperature.

no-coast-punk

The throttle enrichment isn't huge on these engines. 9% at the very largest spot. Above 4k RPM there is zero enrichment. Flow velocity is so high at that point that enrichment isn't needed.

Enrichment is there to deal with a transient change in airflow that isn't metered due to the MAF being ahead of the throttle plate. If you snap the throttle open, you will have a moment where more air enters the combustion chamber than the MAF thinks is there.

You can zero out the throttle tables (simply change every cell in your "Throttle Fuel Gear X" to 1) to get rid of this problem while tuning. It's just not something that you can easily drive the car with. You have to make VERY gradual changes in throttle or it will stumble and **** up. Can be quite dangerous if there is traffic. Not too bad if you are working on a dyno or completely abandoned road.

Altitude doesn't matter. Altitude = less air density. Less air density means less air flowing through the MAF. Clever huh?

no-coast-punk

Adjusting MAF scaling is effective if the MAF housing has changed (such as with an aftermarket intake). If no changes in the MAF housing have been made, why bother with something Mazda got perfect? If your MAF is reading differently than what that table says, it means your MAF is failing and should be changed.

Yes, there are production variations, but you're talking like 1-2%.

The trouble with MAF scaling is this:

It is only effective for the VE curve you tuned it to (such as the load cells the engine sees on a dyno at WOT).

Let's say you have a MAF voltage at a given RPM and load where the engine has 50% VE. At that same MAF voltage at a different RPM/load you could have a VE of 100%. The actual amount of air entering the combustion chamber is much different between these two situations. This will throw your AFR's over the place in a situation like road racing, where the engine will see all sorts of weird load cells. (this is a huge exageration, on a stock car, you have variations of less than 15% between the lowest and highest VE). This leads to some weird behavior in transient or part throttle situations.

For drag racing it doesn't matter as much.... unless your air density changes. Then you're back to square 1.

The VE table on a stock car is quite good on an engine that fits the engineers statistical model for engine wear and other tolerances. If you had an engine that wore (and hence breathes) the exact same way as their average statistical engine does, there would be no reason to touch the VE table. We don't live in that perfect statistical universe.

Start throwing mods on a car, and the volumetric efficiency will change. You actually predict about how much more power your engine will make based on changes in the VE table. 10% more VE due to your mods, and you will see about 10% more power.

This is why COBB recommends that you don't use their stage 1 map on a car with mods. The VE changes are too big and you will go lean near peak torque.

Wolfe

iTrader: (1)

Yea I know, I just thought I would mention it. I could get on a Dyno, but I need to know what I'm doing first before I go pay for Dyno time.

no-coast-punk

The reason I don't care about LTFT is this:

The moment you do a reflash, it clears those values out.

If your short term fuel trims never exceed 10%, long term trims will be a straight 0 forever.

The goal is to get the STFT's as close to zero as possible.

With enough time and logging, it's possible to get STFT's under 4% all the time. Anything under 10% is acceptable. The closer to 0 you get, the better your transient response will be.

EviLStewie

Thanks Punk

Good info there.
Really good stuff.

So what are your logging procedures that you like to do for street tuning?

Light cruise in CL maybe at different RPM intervals?

no-coast-punk

Honestly? For cruising stuff, I just pull long logs when I do things like drive to work and the grocery store. The AP's are cool as **** for this. No laptop needed for logging.

When I get home I just chill in front of the TV with a glass of scotch and massage the maps. I look for trends. I see an area that is always 5% too high, I add 5% in the VE map.

The next day, I flash the new map in the morning and go about my business.

It's not a fast way to do it, but it's a convenient way. You also hit every damn cell in the map a bunch of times just doing normal driving.

Within a few days, you will end up making substantial changes and get pretty damn close.

Brettus

iTrader: (2)

Very interesting approach . I have got good results by just tweaking the fuel tables and maf cal(in closed loop only)and not bothering too much with the Ve table . What do you see as the advantage of tuning VE vs fuel table ?