newton982

I have a pretty straightforward set-up with K24s, Exhaust, Headers, Intake & GIAC flash (peaks at 1.1). I have the durametric software/cable, but haven't yet had a chance to use it. I'll have time to try it out next week and need some assistance on what to log. From a search on the forum, I got the following:

• RPM
• Engine load Intake air temperature
• Ignition angle
• Oxygen sensing bank 1 or 2
• Lambda setpoint, B1 (AFRs)
• Adaption, range 2 (FRA) bank 2
• Boost pressure of sensor
• Duty cycle (%) = (Inj. time)*(RPM)/1200
• Throttle position sensor 1

Is there anything else that needs to be on the list? What is an acceptable range of values for each parameter?

Also, what is the best method to log the data? I read that a 3rd gear pull from 2000rpm to redline works best - is this correct?
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Macster

Does GIAC give any hint about what it checks/logs and under what conditions it logs this data when it qualifies its flash as being acceptable?

(It occurs to me too, with the benefit of hindsight, that a baseline run or two taken before the changes were made would be nice to have to compare to readings taken after the mods.)

My first impression would be to with the engine warmed up to log a hard acceleration run starting in 1st gear and at idle accelerating hard to redline, then upshift to 2nd and continue the hard acceleration to redline and then shift up to 3rd and continue to redline.

Be sure you give the engine a chance to cool down before you pull over to analyze the data.

My thinking is you want to ensure the engine pulls cleanly from off idle all the way to redline, that the readings are ok throughout the rpm range and over a span of time. My thinking is just a hard pull from 2K to redline in just one gear may not be sufficient to uncover a weakness in the flash or the setup.

A hard pull through more gears, over a longer period of time, if the engine's fueling needs change as things get hotter this might make itself known by the readings of whatever you log changing and for the worse.

Also, most engines spend their time at 30% load or less which means you want the fueling to be spot on during times the engine is not under near full throttle operation.

If you want to be thorough a similar run but with less than full throttle acceleration might be interesting.

Sincerely,

Macster.

newton982

Thank you Macster. I'm not sure about the details on the GIAC flash except it is the standard one that is used for K24s. I can log under a variety of conditions, but I'm not sure how to interpret the data. Honestly, I'm not even 100% sure what all the parameters in my list mean - I found them as recommended to monitor when I did a web-search.

If anyone can shed some more light on what each of the parameters mean and an acceptable range of values, I'd much appreciate it.

Macster

Are you attempting to diagnose a symptom/behavior or just curious?

If the latter just log the data and post for comments.

If the former, post more detail on the symptom/behavior.

I'm pretty busy at work right now but let me see if I can off line type something up about the various parameters you ask about.

Here's some info I typed in right now.

RPM -- engine speed.

Engine load -- derived value, calculated value. IIRC the formula is

LOAD_PCT = (current air flow / [ (peak airflow @ WOT @ STP as a function of rpm) * (BARO/29.92) * SQRT(298/(AAT+273))]

where:
STP = standard temperature and pressure = 25C, 29.92 in Hg BARO

WOT = wide open throttle

Characteristics of LOAD_PCTare: reaches 1.0 at WOT at any altitude, temp, or rpm for both NA and boosted engines; indicates percent of peak torque available; linearly coorelated with engine vacuum; often used to schedule power enrichment.

Intake air temperature -- a reading supplied by the MAF. Generally the closer to ambient the better. Above ambient means either the air is being heated by a heat soaked instake system (which of course cools down as the engine runs and the car moves along) or the air is being drawn in from a hot place. My Boxster's intake air temp runs at least 10 or more degs. F above ambient because the Boxster's engine air intake is located at a particularly hot location; the Turbo's intake air temp runs quite a bit cooler, very near ambient, IIRC.

Ignition angle -- probably refers to ignition timing advance. This varies based on many factors.

Oxygen sensing bank 1 or 2 -- Probably refers to the #1 O2 sensor readings from both banks. These are wide-band sensors. My reference indicates each sensor reading is 4 bytes in size. The 1st 2 bytes are the equivalance ratio (lamba) with a min value of 0 and a max value of 1.999. The next 2 bytes is the oxygen sensor current with a min. reading of -128mA and a max reading of 127.996 mA. The Obd2 PIDs used to obtain these values are in the extended range (above the 1st 32 Pids) and I have not yet bought an OBD2 code reader/data viewer/logger that can read these. (I have checked their reading with readers that I have at work but I do not have a sense for what the normal range of values wants to be. Ditto the lamba readings.)

Sincerely,

Macster.

newton982

Thanks Macster. Car is running fine so it's just more out of curiosity.