H22toF20

Sense I know there are at least a couple DIY guys running the AEM V2 now, I figured this would be a good thread to start for some collective thinking. Just post up some questions if you have any, answer the questions if you can and/or both.

Here are my questions.

1. My biggest trouble right now is off idle(taking off from a dead stop) and fast adjustments of the gas pedal. They all result in a lean condition and no power. I'm thinking this is, what on S300, is referred to as the "tip in" enrichment. I think timing is also part of the off idle portion of the problem. What is the "tip in" referred to on this EMS?

2. During deceleration(zero throttle, above idle) I get loud popping coming from the exhaust. It sounds like my friends Le Baron turbo if anyone has heard one. Why does it do this? My wideband shows zero fuel being injected(like it should) so I see no reason for this. Is their a parameter I'm missing?

jh4db536

Fast adjustments to throttle from idle require the rpm offset map to be setup on the idle tab. (might not apply to a tps based fuel map)

This is because the idle control is fighting your adjustments because its trying to maintain target idle (ems only knows it's idling condition, maintain 1k rpm, you're trying to push it up, and the idle control closes to bring it back down to 1k). That map allows the idle control to understand that you're trying to blip the throttle when the ems is trying to maintain idle. The map has to be setup to override rpm for little tps inputs until it eventually pushes the ems out of the idle condition range.

Maybe you are referring to the accel/decel fuel trim? Check out the fuel trim tab.

I'm personally using a map based fuel and timing map. I think the aem basemap is tps fuel and map timing.

https://www.s2ki.com/s2000/topic/804...ase-map-setup/

check out AEM's 279pg tuning manual...i read part of it, i should probably read it again
http://www.aemelectronics.com/Images...%2030-6905.pdf

check out page 148 through 158


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H22toF20

Awesome thanks! I'll start reading it after work tonight if I have time.

sohc_mshue

Sounds like your accel enrichments need adjusting. You also need to change your fuel cut settings. If it is popping then on decel then there is still fuel being injected...not enough to register on your wideband, but there is some.

H22toF20

Yeah I was thinking that there had to be some fuel being dumped in on decel for the popping to occur. Where are these setting at? I guess the real question would be, what are they called?

I'm debating on switching to the calibration that had the TPS based fuel table. Seems like it would be much easier to street tune the A/F. Any input on this?

H22toF20

Alright, I found the TPS % fuel cut off. Looked at a log, so my decel should be fixed. Now for my other issue.

Would the other issue be from the Accel vs throttle table? How would I go about changing that? I don't understand what the Accel modifier % even means.

jh4db536

From what I understand the accel modifier is just a function based on a condition change in the tps sensor which you define the sensitivities and range for. The accel vs fuel is a function of a function that actually changes the fuel injected based on the accel value curve that you setup....

It's a fuel multiplier function that increases/jolts fuel (on the fuel map) when a change "delta" in tps is detected - mashing the gas pedal. You get to define delta tps by % change, the absolute limit of the multiplier, the function itself (sensitivity, base accel curve, and amount % that you mashed the tps), the decay of this fuel jolt, and finally the compensation for temperatures of this function

Pretty complicated and I don't understand it myself...I paid someone to figure this out for me but I didn't learn anything. When live tracing these functions during driving it doesn't seem to move much for me. Hopefully when you figure it out I will finally learn what is going on.

I'm really hoping we can make a thread that explains how to make a basemap from scratch with screenshots and datalogs annotated explaining all the functions needed to get driveability. I attempted in my cold start thread...

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H22toF20

Seems that I'm getting out of my knowledge level now.

I'll be trying out the TPS calibration tomorrow.

jh4db536

Thought i might update based on my little experience...please correct me if im wrong

Just to start off, i have paid 3 (real dyno) reputable tuners in the last year for "full tunes" and NONE of them even touched the accel tables from the default calibration. The more i learn, the more depressing it gets - I'm not going to name any names, but it's really scary if you have no idea what is going on. A huge question i continue to have is how to even motivate the owners of a dyno tuning shop to do a complete correct job. i could never got an honest answer on "how much does it cost to do it right?" I seriously don't even think money motivates them; i bet i could prepay them double their asking price and many corners would still be cut in the end.

Back onto topic:

Assumptions: Normal aspiration, stock intake manifold (no ITB), and MAP based Fuel Table (w/ TPS correction). Basically MAP is the primary source of determining what the fuel or ignition is, but certain situations require TPS override ie. Accel Fuel (also called Throttle tip in on Hondata? no idea how to use K/Fprotuner) or Deceleration Fuel Cut

What is this Accel Tab in AEMTuner? What does Accel fuel do? Why is it important? How do i set it?

The accel tab contains some important options/tables:

1) The first is [Fuel Off] deceleration fuel cut - basically when to cut fuel when you let off the gas. This is based on TPS sensor and MAP sensor. It is important that your TPS is calibrated correctly or this wont work right and should be setup when the engine is warm to compensate for temp drift on the TPS sensor. Your mileage will suck if fuel isnt being shutoff when you let off the gas and you will get popping exhaust etc. It's basically set at the lowest TPS range and maybe a smidge higher to compensate for drift on the sensor. To set the MAP parameter, you'll have to examine your logs to see where it averages when you let off the gas. There is a RPM override obviously so that it doesn't kill the engine. It's usually set around 2000 rpm (highest value on idle table), so that the idle tables take over and let it down slowly to normal idle rpm instead of shutting the engine off. There's so many logical connections in AEMTuner, but they arent obvious...that's why the learning curve is so steep on this thing and Hondata is so much easier supposedly since you just tell it what rpm exactly to idle at and that's the end of it. Control is vast that you have to think about how everything interrelates and different fuctions in different tabs must align with each other during setup.

TPS override of MAP is required at idle because, vacuum is very high and subject to interference by the idle control valve, the rush of air from a fully closed throttle plate cracking open, etc.

2) Accel Fuel compensation is needed because in a MAP based fuel map, the relationship between MAP vacuum and airflow becomes non linear when the throttle plate opens suddenly. The air rushes into the engine (causing vacuum to drop which puts you on a higher cell on the fuel table/the amount of fuel during stable airflow is insufficient at that load level) - a lean condition occurs (see Pic2).

leave global sensitivity default at 89.9. The accel limit is the max accel fuel that will override on calculated accel fuel - make sure it's high enough so that you aren't being overridden.

In order to compensate for this, the EMS must be able to quantify a fast change in TPS with a factor (+dThrottle aka Delta TPS aka Accel DTPS). The useable range for this factor in my experience is like 1.5 to 25%. 1.5% might mean you pressed the gas pedal and 25% means you stabbed the throttle really fast. This is the top left table in the default AEMTuner Accel Tab.

The amount of Accel correction also is different at each TPS level - this is top right table in default AEMTuner Accel Tab. This is a logical relationship - if you go from 0 to 100% TPS, the rush of air would be bigger than if you were already at 100% there is no more change. So it starts high and ends low. This relationship should be left alone, the only thing you might do to this table is move the whole curve up or down (think like econ classes...shifting supply and demand curves) so it becomes a multiplier factor - accel function is not very sensitive to changes in tables sometimes (see Pic1 vs Pic 4)

Finally the Accel RPM table - this is bottom left table in default AEMTuner Accel Tab. This table is where you are going to spend most of your time tuning. The accel factor needs to change based on the RPM that you mashed the throttle at, it will probably look something like your fuel curve because the number will multiply with whatever value of the fuel table at the instant of +dThrottle event. Compensation on high cam will be less because the fuel map value is higher than when on low cam.

To set it, i would make dTPS Accel table flat 50% factor (tune after RPM dependent variables). No changes need to be made to the coolant temp table - tune when your car is at operating temp. The relationship between TPS % should remain untouched, just scaled up or down.

You might need to increase the Accel Decay factor (Accel pump sustain). I left mine at around 10%, and you shouldn't change it much after you have set the Accel RPM factor on a really low RPM. The decay is logrithmic, so it's very sensitive at low rpm. You will adjust this with a low RPM factor then essentially forget about it.

Log the Accel Tab and setup your AEMLog similar to mine (Pics2 & 3). So remain at 1500rpm in like 4th gear, mash the throttle really hard but consistent about 3-4 times. Adjust the Accel vs RPM at 1500 until the lean condition goes away. Do the same thing at 4500 rpm or before vtec rpm. Use the left, right, and horizontal extrapolation to fill out the table for low cam. Do the same logs for high cam ie 5000 to 8000 and extrapolate that range, will get you in a ball park. if you want to be more exact, then you can log every RPM breakpoint.

Lastly adjust the dTPS Accel table that you left flat previously. This requires you to revisit the RPMS that you adjusted in the last steps but mash the throttle at different deltas. This one is pretty difficult to log and adjust, i suggest picking 4 rpm breakpoints and really making use of the interpolation functions. If you are an excel pro then you can try statistical analysis on exported log data and attempt a linear regression (calculate slope for the table). Just remember the useable range is pretty much finished at 25%.

Accel Fuel + Fuel Table + (other trims) = Actual Injector Fuel

Accel Fuel = Fuel Table x [global Sensitivity] (leave default 89.8) x +dThrottle Factor x TPS Factor x RPM Factor x Decay Rate (based on RPM; less rpm = slower)

This is example of default Accel tab:

This is what your log look like if Accel is not calibrated even if you have a dyno tune and perfect fuel map:

This is accel fuel in action:

This is what my tables ended up looking like (shape and correlation focus):

pastoli

WOW, you are the man!!!! I messed with these settings on my part throttle tuning, and my car drives really good. I still have a lot more messing around with it, but..... It drives alot better!