AEM Ultimate Resource Thread>>>>

[mjannusch]

A couple extra notes for you...

When you are setting the calibration, do not run the engine. Just unplug the sensors from the gauge harness, turn ignition to On, and do your calibration. When done, hook the O2 sensors back up to the gauge harnesses.

If you run the engine with the sensors not powered up it may dramatically shorten the sensors' lives. (Carbon may collect in the sensor cell, and if enough accumulates in there then the heater element in the sensor may not be able to burn it off).

[Heikki]

Is anyone using the 2-step with success? I played with it some but it seems that I can not get it to keep the rpms steady and build boost past 1-2 psi.

Depending on the fuel or ignition settings the engine either lopes within +/-~400 rpms from the set limit or barks&bangs from unburned fuel.

I am going to the track soon and I would love to use the 2-step for all-out launches. What settings would you guys recommend I should start with?

Heikki

[lethal_vr4]

Sounds to me as if your two-step is working fine.

[HilbillyHomeboy]

He should be able to build more boost than that on 18g's.

Jeremy

[mjannusch]

Set up the drag-race antilag stuff to around 15 degrees retarded (-15 advance), should be able to build about as much boost as you want. Your transfercase is going to hate you.

No matter what it'll bang and backfire, that's just how it works. You should be able to tweak the timing/fuel cut parameters to help stabilize the target rpm better. Set fuel cut at a higher rpm than timing cut/retard.

I haven't played with it a lot yet, but did have it working the last time I was at the dragstrip. Transfercase go boom.

[slava]

2nd step is working pretty good on stock turbos. I can build 8-10psi without backfiring (ign cut). I will post logs in a little bit, i need your guys opinion. This is the last week for drag strip so i wanted to try the car out but hesitating because of the knock thing.
I the higher i set 2nd step the more boost i can build , i tried 3.5K and i could not get much boost without hitting ign cut and backfire. Once it backfires a couple time either plugs are getting wet or something but then car runs like crap for 20seconds so there is no point launching it.

[xwing]

AEM Battery Voltage Question: Are people logging this during runs? Is the AEM voltage readout low for you?

ON AEM COMPUTER READOUT, my battery voltage at idle is about 12.3-12.5 volts; on drag or roadcourse running at high rpm's it can drop to 10.9V.
AT BATTERY on a digital meter, it is 13-14.4 volts, within spec, and handles loads well. At the cigarette lighter inside car, it is about 12.6 (loaded with all lights,fans,radio,rear defog on) to 13.8 (unloaded).

I have alot of current draw, with 2 large electric fans ~28amps, MSD DIS4-HO (~1 amp per thousand rpm), 2 Walbro pumps, power adapter/laptop, heater/fans on max on roadcourse, even an auxiliary waterpump I use on roadcourse (<10 amps), but some of these are tapped direct to battery +.

Still, with the 91-95 alternators rated at 110amps, alot of that stuff NOT running/at max, I would expect voltage to be around specification of 13.1-15.4 V. It is annoying, because AEM could conceivably start acting funky with 10.x voltage range...I wonder if I need to run heavier/more positive power "bussbar" lines to the car's interior/computer harness electricals. I have the MSD and some other things tapped direct to battery + to avoid such problems but maybe there is a weak link, poor ground to AEM or something...

Just was tuning my buddy's Supra AEM maps and he has nice average 13.4+V at AEM where I see average 12.4V, max 13V, min 10.9.

Interestingly, I had to get a low-voltage-handling power adapter (10-14v input, 14v output) for my laptop, because 2 different power inverters went into "alarm/no charging" despite being rated at 500watts. The low voltage unit also drops out sometimes/into saftety mode. I think these power inverters and power adapters may overestimate their output capability, or underestimate laptop current draw (I have IBM Ti22 Thinkpad).

Basically, there is about a 0.8 to1.7 volt drop between battery and AEM readout! When battery voltage was up to 14.4, AEM read like 12.7.

So, anyway, what voltages are YOU all seeing on your AEM logged/voltages?
Thanks!
Jack T.

[mehlosTT]

Jack,
I have always logged Volts and with the 221,000 mileage alternator she would still show 13.2 to 13.4 volts at WOT until I hit 5K rpms where she would dip down to 12.6 -12.7 volts as logged on the AEM ems.
That is logged with running a power converter for the laptop and fans on...those converters really_ make the alternator work hard.
Let me check with Andrew son and see if that is correct....he can do the math and get a better idea on things with the data you listed for conditions to better trouble shoot. Sounds like the alternator is doing it's job but it gets over taxed for higher rpms(?) with that power converter running.
Kim

[xwing]

Kim:
The alternator seems to be doing fine, as it is maintaining voltage pretty nicely as measured directly at battery. I first was thinking voltage regulator in alternator, but when typing the above message went out and measured voltage direct at battery, compared to AEM readout, and cigarette lighter.
The voltage that is dropping alot is only as read at AEM computer, so I am thinking there might be a bad ground and/or positive to the computer, its internal voltmeter is inaccurate.

Point is, there should not be a drop of 1.7 volts from battery to AEM readout!
If you are also getting a relatively good 13.2-13.4V at AEM readout, I must have a bad power lead going to the AEM, or maybe my AEM voltage readout calibration is wrong. Next, will have to tap into input of AEM main + to see if voltage is low going in...if not, it is the AEM internally/calibration.

Jack
ps the adapter I now have is more efficient than a power inverter/transformer setup. The Lind adapter goes takes 10-16VDC input, and outputs a regulated 16VDC direct to laptop (instead of a power inverter stepping up to 120AC, with laptop transformer plugged into inverter to rectify and drop voltage BACK down to 16VDC...that is 2 power conversion steps, the Lind is only one).

[pengulns2001]

yeah somethings messed up i just went through 10 logs and the lowest ive seen on any including some of other peoples cars is 12.4...