great ET, but bad atap reading...graph attached...
04-08-2002, 09:36 AM
#1
great ET, but bad atap reading...graph attached... i took my new combo to the track for the first time this weekend. my best time was 12.0 at 118.25 with a 1.90 short time; i didn't not atap that run. (ALL RUNS ON BFG DR's) i ran a few more 12.1's at 118 as well. the run i atap'd was 12.2 at 117.6 with a spinning/bogging 2.07 short time. here is the graph:
http://www.angelfire.com/nj2/ponycars/atap4602.htm
i would like your input. here are my thoughts:
-I am mostly concerned with injector pulse width; i am afraid i'm running out of injector and running too lean (but do my O2's correspond with that?).
-lower mph than previous runs becuase car was hotter (see temp column; peak power usually made at 190 degrees; long wait before i got to run).
-lower ET than previous run because i spun and bogged (horrible short time; previous run was 1.90).
-lots of knock retard in first three gears.
-O2 sensors seem to be really rich, but julio said those narrow band O2 sensors are not accurate because they only work in a narrow temperature range.
-since timing seemed OK at the top end, i think my mph won't increase when we finish tuning, but the ET will probably increase because the mid -range is where my timing is low.
background...i had LS1edit before these runs, but the fuel pressure was really low (see my webpage, "my dyno tests"), so we stopped the LS1edit session until i got a new pump. I now have a stock replacement pump, but haven't finished the LS1edit yet (i will soon though).
thoughts? thanx!!!!!!!
<small>[ April 08, 2002, 09:40 AM: Message edited by: 2MCHPWR ]</small>
http://www.angelfire.com/nj2/ponycars/atap4602.htm
i would like your input. here are my thoughts:
-I am mostly concerned with injector pulse width; i am afraid i'm running out of injector and running too lean (but do my O2's correspond with that?).
-lower mph than previous runs becuase car was hotter (see temp column; peak power usually made at 190 degrees; long wait before i got to run).
-lower ET than previous run because i spun and bogged (horrible short time; previous run was 1.90).
-lots of knock retard in first three gears.
-O2 sensors seem to be really rich, but julio said those narrow band O2 sensors are not accurate because they only work in a narrow temperature range.
-since timing seemed OK at the top end, i think my mph won't increase when we finish tuning, but the ET will probably increase because the mid -range is where my timing is low.
background...i had LS1edit before these runs, but the fuel pressure was really low (see my webpage, "my dyno tests"), so we stopped the LS1edit session until i got a new pump. I now have a stock replacement pump, but haven't finished the LS1edit yet (i will soon though).
thoughts? thanx!!!!!!!
<small>[ April 08, 2002, 09:40 AM: Message edited by: 2MCHPWR ]</small>
04-08-2002, 09:56 AM
#2
Re: great ET, but bad atap reading...graph attached... interesting observation...
look at the knock retard column.
why is the knock retard coming down from a high of 3.70 to a low of .50, in a nice orderly fashion, getting lesser and lesser as the run progresses?
look at the knock retard column.
why is the knock retard coming down from a high of 3.70 to a low of .50, in a nice orderly fashion, getting lesser and lesser as the run progresses?
04-08-2002, 01:01 PM
#3
Re: great ET, but bad atap reading...graph attached... Would a 160* thermostat help at all? Keep in mind that it doesn't keep the coolant temps at 160*, usually runs up to around 174*-185* depending on fan settings and you might need that while waiting in long staging lanes, especially in the summer. I use a 160* on a stock motor even. <img border="0" alt="[Chevrolet]" title="" src="graemlins/camaro.gif" />
04-08-2002, 01:08 PM
#4
Re: great ET, but bad atap reading...graph attached... thanx marc. i may install the 160 t-stat tonight.
Just thought of something and I figured I'd share it with you.
When I did ls1edit last month, before we figured out that the pump was bad, we programmed the injectors to go rich in hopes of curing my lean condition in the top end. when that didn't work, we tested the pressure and noticed it was low, so that was the end of the ls1edit session. therefore, we left the injectors rich.
well now that my pump is replaced and is working properly (i hope and won't be able to be certain until we hook it up again...shortly), since the injectors are set to rich, that would explain those high O2 numbers. right?
but i still don't know about the KR. i hope my exhaust isn't banging. i don't think it is.
I just read a post saying that powershifting was causing some KR, but nineball's "KR box thingy" fixed that.
any other thoughts?
thanx!!!!!
Just thought of something and I figured I'd share it with you.
When I did ls1edit last month, before we figured out that the pump was bad, we programmed the injectors to go rich in hopes of curing my lean condition in the top end. when that didn't work, we tested the pressure and noticed it was low, so that was the end of the ls1edit session. therefore, we left the injectors rich.
well now that my pump is replaced and is working properly (i hope and won't be able to be certain until we hook it up again...shortly), since the injectors are set to rich, that would explain those high O2 numbers. right?
but i still don't know about the KR. i hope my exhaust isn't banging. i don't think it is.
I just read a post saying that powershifting was causing some KR, but nineball's "KR box thingy" fixed that.
any other thoughts?
thanx!!!!!
04-08-2002, 05:02 PM
#5
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Re: great ET, but bad atap reading...graph attached... </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 2MCHPWR:
<strong>interesting observation...
look at the knock retard column.
why is the knock retard coming down from a high of 3.70 to a low of .50, in a nice orderly fashion, getting lesser and lesser as the run progresses?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">That's the way KR works. The decay constants affect the speed with which the initial timing hit gets added back.
<strong>interesting observation...
look at the knock retard column.
why is the knock retard coming down from a high of 3.70 to a low of .50, in a nice orderly fashion, getting lesser and lesser as the run progresses?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">That's the way KR works. The decay constants affect the speed with which the initial timing hit gets added back.