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pwnd
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Guess you are talking about that little dip it took.....Interesting. Did he floor it the whole time
. Thats the auto isnt it? Could be when he got into 3rd then floored it the engine pulled timeing for a second ... who knows.
 

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Discussion Starter #3
By he, you mean me then. I was driving the car on the dyno. It was in 3rd gear, OD off. It was NOT a downshift/upshift. I was able to keep the car in 3rd on the last run. The dip was there in all 4 runs. Now if we had had another auto SR20 to compare it to, then that would have been nice. Hmmm, I wonder where we can find one of those?????
 

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Eric, Jacen had a good point, he said it could be an ECU thing. Maybe its thinking it is time to shift, but w/ OD off it realizes it should stay in 3rd. But I'm not too worried about this car, something different might present itself to me later this year...[evil laugh here] hehehe. later.
 

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pwnd
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I had to choose between groceries or gas money. Well I wanted to eat the rest of the week. LOL I can come down sometime soon maybe, or you can come up
. I dont have the money to be straped to a dyno either.

But Ive never had that problem. I drive around with the OD off alot now. How did you keep it from down shifting at WOT? Didnt start the run till like 80? But did the dip go along when you floored it? From what I have read the ECU will pull timeing when you floor it then dial back in the timeing. I dont have proof of this but read it on the 240sx site and figured that the ecu's couldnt be that different. What did the car do when? Im interested what did the graphs look like?
 

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Discussion Starter #6
Here's the dyno graph. The first run(red) was 17 deg timing. You can see the shift at 4000 rpm, and the "dip" at 4500prm. In the last run(blue), I got on the gas at 50 instead of 30 the 3 runs before, and this kept the tranny in 3rd, but you can see the dip at 3500rpm. It also looks like 17 deg timing can give 3hp. The only mods are JWT POP and the timing. Looks like I need to put your timing back to 17 David.
 

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OK Eric, after extinguishing all my car resources, I came to this conclusion as to why the hesitation ocurred.............vtec was not kicking in! it was trying to but there was just no enough oil pressure..hehee. Just thought I would throw that in there.later
 

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pwnd
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hmmmm idea....maybe knock sensor? Either had some detonation or something vibrating or really crazy knock sensor. Kinda werid that its exactly at 4500. That kinda sparks something in my head about the sr20 being more prone to detonation around that area, or something along those lines. I could be talking out of my ass there. Ive never had that happen, you even drove my car a couple times the first time with low timing it was hell, but I dont remember if you have driven it since then. I would guess the engine is pulling timing out for various reasons....pinging...ecu doing it at full throtle...something along those lines.

Or I could just be talking out of my ass on this one
 

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pwnd
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Just that upwards spike it does that kinda leads me to believe it got really hot...made more power for that instant, knock sensor kicked in and pulled some timeing, then fed it back in slowly. I think thats how the knock feature works...
 
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