Sea Level vs Altitude Tuning

***cleatus12r*** · #1 Tue, May 5th, 2009, 05:53 PM

Where have you ended up, DJ? Any updates on your progress? Are you happy with what you have developed on your Fuel Sipper tune?

Inquiring minds want to know. Have you figured out the dead throttle when cold yet or can I give you a hint?

soutthpaw · #2 Tue, May 5th, 2009, 06:18 PM

I just PM'ed Corey and she is gonna bug Bill to give us his input here... I did take a trip to Denver on Sunday with the Fuel Sipper tune and it was good.. gassed up at 18.1MPG. The throttle is more responsive now in that tune.. as for the Dead Throttle I didn't find the fix though I believe there is a setting for min trans temp or oil temp before the throttle will respond??? I tried increasing the Throttle pedal travel by grinding off the metal stops on the pedal and it just gave me errors over 90% or under 10% then the engine did not want to respond to the throttle so welded the metal back on and reset it to stock and its fine.... not sure why it only has a range of 10 to 86%. Again I think there is a setting to trigger high and low throttle position... not sure if it would make a difference if floored showed 98% instead of 86% though??/

***cleatus12r*** · #3 Tue, May 5th, 2009, 09:12 PM

DJ,

In order to not give away Bill's tuning expertise and secrets, I have "trimmed the fat" on this screenshot. This is the program in question vs. stock. Can you decipher WHY there is a dead pedal while the engine is cold all else being the same? The answer lies in these two maps.

Keep in mind that 40 degrees "C" is equal to about 100 degrees "F" and 100 degrees is a very cold engine and the actual additional pulse width above stock does not start to get multiplied until the engine temperature is above 22 degrees C (72 F). I don't know what the weather is like there but I haven't started the engine yet with the ambient temperature above 55 degrees and it takes a good while for the oil temperature (what the fueling is based on) to get to temperature.

Oh and as far as your data goes with APP percentage....what does the VOLTAGE say? The highest readable voltage that the PCM can compare to ground is about 4.75-4.8 volts. The software you are using may base 100% on a full 5 volts which is giving you the problem you are seeing.

***cleatus12r*** · #4 Tue, May 5th, 2009, 09:17 PM

Here is the attachment screenshot.

soutthpaw · #5 Tue, May 5th, 2009, 09:41 PM

scratch this response I missed your comment on the previous page.... Ill read it then get back to ya

soutthpaw · #6 Tue, May 5th, 2009, 10:43 PM

its easier to see once i put it in the graph format. That sure is weird at 22C. Like I said before, it must be that way due to some boneheaded emissions testing. Bet it would not be as obvious if I was running 5w40 synthetic, which i will be switching too next oil change. so if i raised that to the 3C level or so the dead throttle should go away?

another question, if i change the negative multiplier in the Adder to Pulsewidth Multiplier would that increase the boost levels? I guess it would be more accurate to call it a subtractor to Pulsewidth Multiplier

***cleatus12r*** · #7 Tue, May 5th, 2009, 11:39 PM

Quote:

Originally Posted by soutthpaw

its easier to see once i put it in the graph format. That sure is weird at 22C. Like I said before, it must be that way due to some boneheaded emissions testing. Bet it would not be as obvious if I was running 5w40 synthetic, which i will be switching too next oil change. so if i raised that to the 3C level or so the dead throttle should go away?

another question, if i change the negative multiplier in the Adder to Pulsewidth Multiplier would that increase the boost levels? I guess it would be more accurate to call it a subtractor to Pulsewidth Multiplier

The thing I was trying to get at is that there is no pulse width multiplication above the stock values until the EOT is above 22 degrees C. Factor in that the low boost fueling is WAY LESS than stock at less than about 5 PSI and you have an absolute turd until there is some boost or until there is some engine temperature. You know that the accelerator pedal is even really "doggy" in stock when cold....well, it's even worse with this program due to the low boost fueling that has been taken away. If the numbers were to represent a percentage, there would be points of 10% less fuel in the Fuel Sipper program for any given boost/RPM combination.

You can put zeros or positive numbers in the "adder" map. It's not going to hurt anything. The PCM will not pull fuel under high boost.