New SD2 Chip is Available!
- Thread starter Eric Stage I
- Start date
Is that something thats capable of being tuned out with the VE table?
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Wondering the best way to do that. I also have a similar lean spike, and in watching the bubble reaction in the VE table just prior and during this spike. I noticed the bubble going from a value of about 79 to something in the mid 80's. Shouldn't that cause more fueling?? Or am I not thinking correctly. I'll show you what I mean be attaching two pictures. One at the rpm peak the instant the 2/3 shift starts and another just down the rpm slope a little as the lean spike is starting. What specifically could be done to the VE table in this instance?
you will have to lower the VE numbers as you notice the correction pulling fuel, as you rise to the top of the gear when the numbers are already lower right before the shift (you have 79's) you might have to increase that number and make the transition more smooth.
Whats happening here is the correction is pulling fuel on the rise up, along with this you have the VE scaling downward so as it reaches the top of the gear the next cell is significantly less, so it sees that cell and applies the corresponding fuel amount. Now you shift, and its basing the fuel on the lowered VE number plus the additional negative correction from the rise up. Its difficult to put down on paper but tweak it slowly and you will see what im talking about.
his corrections are small, so the tune is pretty close in this area. if you can get repeatable test conditions I would do the following:
at the top of the gear its pulling a little bit of fuel, meaning that the table is rich there. when the RPMs drop back on the shift the correction is still negative since its not instantaneous. the tune is not overly rich at this lower RPM, so the negative correction causes a small lean spot.
my suggestion, take that 79 column and make it 78. then make an identical run to see what happens at that spot. you would expect to see the negative correction at the top of the gear be less, or just slightly positive. Your lean dip should be less or gone.
Bob
at the top of the gear its pulling a little bit of fuel, meaning that the table is rich there. when the RPMs drop back on the shift the correction is still negative since its not instantaneous. the tune is not overly rich at this lower RPM, so the negative correction causes a small lean spot.
my suggestion, take that 79 column and make it 78. then make an identical run to see what happens at that spot. you would expect to see the negative correction at the top of the gear be less, or just slightly positive. Your lean dip should be less or gone.
Bob
haywire4130
Active Member
- Joined
- Sep 11, 2010
I'm more interested in a series of "speed/density for dummies" videos on youtube where you take a typica recipe buick and slap a sd2 chip in it and hold our hands step by step on how to get the most out of it hahaha. You know, when you guys get a little idle time between technological breakthroughs ;-)
Bob/Eric, as I told you about my laptop demise, I decided to try some of those "pedal stomp" adjustments via the scanmaster. Since I have a moderately close tune now, but can't get access to the VE or target AFR tables (because of my sick sick laptop), so I made some cell adjustments. What I did was change cells 2, 3, and 4 from 97 to specific Air Fuel ratio values. I set cell 2(idle cell) to 14.5 (145), and set cell 3(cruise cell) to 15.0 (150), and finally set cell 4 (WOT cell) to 11.3 (113).
Car still drives perfectly with outstanding throttle response, particularly the 1/2 throttle or below stuff that one uses on the street all the time.
I did notice, that while set to the values above, the idle cell hung around closer to 14.2-14.3, and the cruise cell hung around closer to 14.8ish. Didn't do any WOT pulls this time out, just too much traffic.
I keyed off between each cell adjustment, was that needed???? It's been so long since I made "cell" adjustment on my Extender Pro, I don't remember having to key off when moving from adjusting one cell to another???
Crap! posted this in the wrong thread! I'll repost
Car still drives perfectly with outstanding throttle response, particularly the 1/2 throttle or below stuff that one uses on the street all the time.
I did notice, that while set to the values above, the idle cell hung around closer to 14.2-14.3, and the cruise cell hung around closer to 14.8ish. Didn't do any WOT pulls this time out, just too much traffic.
I keyed off between each cell adjustment, was that needed???? It's been so long since I made "cell" adjustment on my Extender Pro, I don't remember having to key off when moving from adjusting one cell to another???
Crap! posted this in the wrong thread! I'll repost
dave calhoun
New Member
- Joined
- Aug 7, 2013
can someone send me the link to buy this chip?
Eric Stage I
TurboTweak Guy
- Joined
- May 25, 2001
