Help needed with ATap results please.
Thread Starter
TECH Enthusiast
Joined: Nov 2001
Posts: 534
Likes: 0
From: Sydney Australia
Help needed with ATap results please. Can someone please help me with my Atap results?
ftp://ftp.holdenls1.com/pub/Downloads
PLAN B
2001 VU SS
Phantom, M6
4-1 Headers
SQP Ported Heads with larger valves
titanium retainers, Crane 1.8:1 rockers,
Rollmaster DR timing Chain,
Camshaft, 112 lsa, 224/224 @ 50 (lift at valve .560)
LS6 intake,
Ported T/B & Maf,
Cold air, K&N intake filter,
All dyno reports are good, 1/4 mile times are great for half track, then it just lays down... In fact... 2-3 mph less than when it was stock...
Compression test, and leak down, is 100% Perfect.
I've gotta fix this.. <img src="gr_sad.gif" border="0">
I have completed a few runs with various tables. TIA
[ December 23, 2001: Message edited by: Plan B ]</p>
ftp://ftp.holdenls1.com/pub/Downloads
PLAN B
2001 VU SS
Phantom, M6
4-1 Headers
SQP Ported Heads with larger valves
titanium retainers, Crane 1.8:1 rockers,
Rollmaster DR timing Chain,
Camshaft, 112 lsa, 224/224 @ 50 (lift at valve .560)
LS6 intake,
Ported T/B & Maf,
Cold air, K&N intake filter,
All dyno reports are good, 1/4 mile times are great for half track, then it just lays down... In fact... 2-3 mph less than when it was stock...
Compression test, and leak down, is 100% Perfect.
I've gotta fix this.. <img src="gr_sad.gif" border="0">
I have completed a few runs with various tables. TIA
[ December 23, 2001: Message edited by: Plan B ]</p>
Re: Help needed with ATap results please. Well I looked at all 3 files. Just comparing to many a-tap runs that I have done personally.
Everything basically looks right for what I would expect from a LS1 f-body. A little bit rich, but that would not really affect anything noticable. However, your timing sucks. It doesn't suck, it's horrible. Flat out something-is-wrong bad. However, you do hit pretty decent timing figures in what appears to be 1st gear (can't tell, you didn't log gears). After that, you're hitting high teens. Not good, not good at all.
For comparison, my stock motored LS1 will do very high 20s at 6000rpm. I have seen 30 and 30.5 once in a while. You're looking at like 19 degrees of timing. I would say that is likely a big part of your problem.
However, no knock, so you're not pinging bad or anything. Do you have custom programming? Aftermarket MAF maybe? Something is causing the computer to pull timing (not knock/ping related). Do you have a vacuum leak perhaps? SES light set? Custom programming? (that is not right for your application).
The only other thing that stood out to me was your intake temps. In one file, it is ~30C. In another, it is ~70C. 30C isn't too bad, but 70C? Isn't that like 160 degrees F or so? That is ridiculously hot, and considering the fact that it's pretty unlikely the intake temps were that high, perhaps something is falsifying the readings? With intake temps that high, the computer might pull timing to try to prevent pinging?
Have you reset the PCM since you did all the mods? Maybe it just needs to relearn everything.
Any other symptoms? How's regular driving? Any sounds, funny stuff, etc?
Dope
Everything basically looks right for what I would expect from a LS1 f-body. A little bit rich, but that would not really affect anything noticable. However, your timing sucks. It doesn't suck, it's horrible. Flat out something-is-wrong bad. However, you do hit pretty decent timing figures in what appears to be 1st gear (can't tell, you didn't log gears). After that, you're hitting high teens. Not good, not good at all.
For comparison, my stock motored LS1 will do very high 20s at 6000rpm. I have seen 30 and 30.5 once in a while. You're looking at like 19 degrees of timing. I would say that is likely a big part of your problem.
However, no knock, so you're not pinging bad or anything. Do you have custom programming? Aftermarket MAF maybe? Something is causing the computer to pull timing (not knock/ping related). Do you have a vacuum leak perhaps? SES light set? Custom programming? (that is not right for your application).
The only other thing that stood out to me was your intake temps. In one file, it is ~30C. In another, it is ~70C. 30C isn't too bad, but 70C? Isn't that like 160 degrees F or so? That is ridiculously hot, and considering the fact that it's pretty unlikely the intake temps were that high, perhaps something is falsifying the readings? With intake temps that high, the computer might pull timing to try to prevent pinging?
Have you reset the PCM since you did all the mods? Maybe it just needs to relearn everything.
Any other symptoms? How's regular driving? Any sounds, funny stuff, etc?
Dope
Re: Help needed with ATap results please. Also, you might want to post complete timeslips, before and after. Are you saying that you're getting good 1/8th mile times but poor 1/4?
Did you do the work yourself? Perhaps the cam wasn't installed correctly, and it may be off some, hence poor timing and lacking power.
Dope
Did you do the work yourself? Perhaps the cam wasn't installed correctly, and it may be off some, hence poor timing and lacking power.
Dope
Re: Help needed with ATap results please. Well, in an LS1 f-body/y-body, Fuel Cell 22 is WOT. (21 is de-accel, 20 is idle, 1-19 are cruising cells).
He's showing 15. I assume that 15 is the WOT cell for the Holden LS1s. If not, that could be an interesting problem, but I assume my assumption is correct <img src="gr_stretch.gif" border="0">
Dope
He's showing 15. I assume that 15 is the WOT cell for the Holden LS1s. If not, that could be an interesting problem, but I assume my assumption is correct <img src="gr_stretch.gif" border="0">
Dope
Thread Starter
TECH Enthusiast
Joined: Nov 2001
Posts: 534
Likes: 0
From: Sydney Australia
Re: Help needed with ATap results please. [quote]Originally posted by Dope:
<strong>Did you do the work yourself? Perhaps the cam wasn't installed correctly, and it may be off some, hence poor timing and lacking power.
Dope</strong><hr></blockquote>
Thanks, I appreciate this,
Moroso Pro Wheel, Mitutoyo dial digital dial indicator with, correct cam follower.. Comp Cam Spec straight up measured .00264" less lift @ 110 deg as per card... 3rd cam in this engine now... The mechanical stuff doesn't bother me.. Just the computer!
Thanks guy’s. All help as to where it should be is much appreciated.
Surely, I should get some joy from my mods?
Peter.
<strong>Did you do the work yourself? Perhaps the cam wasn't installed correctly, and it may be off some, hence poor timing and lacking power.
Dope</strong><hr></blockquote>
Thanks, I appreciate this,
Moroso Pro Wheel, Mitutoyo dial digital dial indicator with, correct cam follower.. Comp Cam Spec straight up measured .00264" less lift @ 110 deg as per card... 3rd cam in this engine now... The mechanical stuff doesn't bother me.. Just the computer!
Thanks guy’s. All help as to where it should be is much appreciated.
Surely, I should get some joy from my mods?
Peter.
TECH Addict
Joined: Nov 2001
Posts: 2,003
Likes: 0
From: Live Oak, FL - in the woods where the creatures lurk.
Re: Help needed with ATap results please. A question I would have is about the kind/quality of gas you have there. Do other LS1s there pull much higher timing? In other words, maybe the lower timing (compared to US LS1) is a factor of the pcm programming due to gas quality,etc.
Enlighten this Yank.
Enlighten this Yank.
Trending Topics
Thread Starter
TECH Enthusiast
Joined: Nov 2001
Posts: 534
Likes: 0
From: Sydney Australia
Re: Help needed with ATap results please. [quote]Originally posted by gwj:
<strong>A question I would have is about the kind/quality of gas you have there. Enlighten this Yank.</strong><hr></blockquote>
I've gone down the fuel track also... VP racing fuel C116 & C103.. We have 98 octane at the pump,, Thats around 93-95 in your rating! (ron,mon) nah! it's not the fuel.. Perhaps it's torque management??? Feels real good on the street.
I'm thinking about a 422ci for next year, but if it does this... I give up. <img src="images/icons/confused.gif" border="0">
<strong>A question I would have is about the kind/quality of gas you have there. Enlighten this Yank.</strong><hr></blockquote>
I've gone down the fuel track also... VP racing fuel C116 & C103.. We have 98 octane at the pump,, Thats around 93-95 in your rating! (ron,mon) nah! it's not the fuel.. Perhaps it's torque management??? Feels real good on the street.
I'm thinking about a 422ci for next year, but if it does this... I give up. <img src="images/icons/confused.gif" border="0">
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo TECH Addict
Joined: Nov 2001
Posts: 2,003
Likes: 0
From: Live Oak, FL - in the woods where the creatures lurk.
Re: Help needed with ATap results please. What kind of timing advance do the LS1s there pull? I wouldn't have a clue if your pcm is similiar to ours. If you think you've checked all possibilities and not getting any problem codes,maybe try getting the pcm reflashed?
Re: Help needed with ATap results please. [quote]Originally posted by Dope:
<strong>
The only other thing that stood out to me was your intake temps. In one file, it is ~30C. In another, it is ~70C. 30C isn't too bad, but 70C? Isn't that like 160 degrees F or so? That is ridiculously hot, and considering the fact that it's pretty unlikely the intake temps were that high, perhaps something is falsifying the readings? With intake temps that high, the computer might pull timing to try to prevent pinging?
Dope</strong><hr></blockquote>
I see the collant temp being 199 or so (68* C).. Do you have a resistor on the AIT to throw it off? I can't see AIT being 154.. That might be what is trhowing your timing off. If you have a resistor in your AIT take it out and go for another log.... I would think if there is a resistor your temp would be solid 1 temp.. Is your AIT not in the air lid and on the intake or something? Or do you live on the sun? Hope you get it figured out..
<strong>
The only other thing that stood out to me was your intake temps. In one file, it is ~30C. In another, it is ~70C. 30C isn't too bad, but 70C? Isn't that like 160 degrees F or so? That is ridiculously hot, and considering the fact that it's pretty unlikely the intake temps were that high, perhaps something is falsifying the readings? With intake temps that high, the computer might pull timing to try to prevent pinging?
Dope</strong><hr></blockquote>
I see the collant temp being 199 or so (68* C).. Do you have a resistor on the AIT to throw it off? I can't see AIT being 154.. That might be what is trhowing your timing off. If you have a resistor in your AIT take it out and go for another log.... I would think if there is a resistor your temp would be solid 1 temp.. Is your AIT not in the air lid and on the intake or something? Or do you live on the sun? Hope you get it figured out..
