VVT tuning with compcams limiter
10-05-2012, 06:24 AM
#1
VVT tuning with compcams limiter I have my swap tagged and on the road now tuning.
https://ls1tech.com/forums/conversio...-t56-swap.html
I noticed that the E38 PCM is commanding cam phasing according to
The tables, but the actual cam won't advance more than 7deg. (which is
Actually 0deg since the VVT-2 cam is 7deg retarded installed). I do have
The compcams limiter that's the correct version for my 2010 cam/phaser
Combo that suppose to have 22deg of advance.
I'm using the single spring PAC1518s and I have 30#+ of oil pressure
With a melling 10296 pump.
Has anyone scanned their VVT engine with the limiter to see what
Cam advance they are commanding & recording?
https://ls1tech.com/forums/conversio...-t56-swap.html
I noticed that the E38 PCM is commanding cam phasing according to
The tables, but the actual cam won't advance more than 7deg. (which is
Actually 0deg since the VVT-2 cam is 7deg retarded installed). I do have
The compcams limiter that's the correct version for my 2010 cam/phaser
Combo that suppose to have 22deg of advance.
I'm using the single spring PAC1518s and I have 30#+ of oil pressure
With a melling 10296 pump.
Has anyone scanned their VVT engine with the limiter to see what
Cam advance they are commanding & recording?
Last edited by 85MikeTPI; 10-05-2012 at 07:40 AM.
10-09-2012, 06:13 AM
#4
Why? Did you see my screenshot that I have logged everything? I'm asking if anyone has gotten more than 7deg cam retard with a comp limiter kit and apparently no one has scanned a VVT motor. I haven't posted on HP as Im trying to gather data to find out where the anomaly is.
10-09-2012, 02:26 PM
#6
http://www.hptuners.com/forum/showth...&highlight=VVT
http://www.hptuners.com/Forum/showthread.php?t=17883
Filtering through all the noise in these posts, it seems that the HPT tables and scanner are in Crankshaft degrees instead of Camshaft degrees. That would imply that my 7deg reported on the scanner is actually 14deg of cam rotation. While it makes sense in that 14deg is closer to the phaser reported 22deg range, it doesn't make sense that HPT labels the PID "Intake Cam Desired Angle" and "Intake Cam Angle".
I'd still love to get another VVT owner with the limiter block to post a scan showing maximum cam rotation reported.
http://www.hptuners.com/Forum/showthread.php?t=17883
Filtering through all the noise in these posts, it seems that the HPT tables and scanner are in Crankshaft degrees instead of Camshaft degrees. That would imply that my 7deg reported on the scanner is actually 14deg of cam rotation. While it makes sense in that 14deg is closer to the phaser reported 22deg range, it doesn't make sense that HPT labels the PID "Intake Cam Desired Angle" and "Intake Cam Angle".
I'd still love to get another VVT owner with the limiter block to post a scan showing maximum cam rotation reported.
10-12-2012, 12:18 PM
#7
I'd still love to get another VVT owner with the limiter block to post a scan showing maximum cam rotation reported.
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10-18-2012, 03:20 PM
#10
Also these numbers are in camshaft degrees, not crankshaft degrees so beware - they should be doubled to represent crankshaft degrees. Here is some info I came across in this thread. I wish this had the phaser P/Ns. It seems to indicate 3 different phaser configurations, so i am really confused now.
For the Gen IV small block engines, the park position for the CMP actuator and camshaft is, 8.5 degrees before top dead center (BTDC), which is equal to 17 crankshaft degrees BTDC, to the next cylinder in firing order. The engine control module (ECM) can only command the CMP actuator to retard the valve timing from the park position, or advance the valve timing back to the park position. The total range of valve timing authority is 31 degrees of camshaft rotation, which is equal to 62 degrees of crankshaft rotation. The control range is from the park position of 8.5 degrees camshaft, or 17 degrees of crankshaft BTDC, to 22.5 degrees camshaft, or 45 degrees crankshaft, after top dead center (ATDC).
The 6.0L L76, 6.2L L92, and 6.0L LY6, light duty application, CMP actuator has a 62 degree range of authority. With the engine not running and no engine oil pressure to the CMP actuator, the high tension spring positions camshaft timing at the 17 degree advanced park position. During normal engine operation and based on performance requirements, the ECM may adjust camshaft timing, as required, within a range from 17 degrees advanced to 45 degrees retard.
The 6.0L LY6, heavy duty application, CMP actuator has a 52 degree range of authority. With the engine not running and no engine oil pressure to the CMP actuator, the high tension spring positions camshaft timing at the 7 degree advanced park position. During normal engine operation, and based on performance requirements, the ECM may adjust camshaft timing, as required, within a range from 7 degrees advanced to 45 degrees retard.
The 6.0L L76, 6.2L L92, and 6.0L LY6, light duty application, CMP actuator has a 62 degree range of authority. With the engine not running and no engine oil pressure to the CMP actuator, the high tension spring positions camshaft timing at the 17 degree advanced park position. During normal engine operation and based on performance requirements, the ECM may adjust camshaft timing, as required, within a range from 17 degrees advanced to 45 degrees retard.
The 6.0L LY6, heavy duty application, CMP actuator has a 52 degree range of authority. With the engine not running and no engine oil pressure to the CMP actuator, the high tension spring positions camshaft timing at the 7 degree advanced park position. During normal engine operation, and based on performance requirements, the ECM may adjust camshaft timing, as required, within a range from 7 degrees advanced to 45 degrees retard.
10-18-2012, 04:27 PM
#11
You're correct, I always reverse advance/retard when I talk VVT because it seems backward to me. My cam is 7 deg advanced base (0 in the PCM table) and will only retard 7 deg when the PCM is commanding 20 or more via the stock L92 tune.
So you're saying the PCM tables are in camshaft deg? Thats what I thought but that makes the limiter really limit in my case..
So you're saying the PCM tables are in camshaft deg? Thats what I thought but that makes the limiter really limit in my case..
10-18-2012, 04:51 PM
#13
https://ls1tech.com/forums/15889632-post75.html
There are other good tidbits of info in that thread if you sort through it, but it got a little too theoretical after a while for me to stay interested.
https://ls1tech.com/forums/generatio...vt-delete.html
11-01-2012, 02:07 PM
#15
I'm using the single spring PAC1518s and I have 30#+ of oil pressure
With a melling 10296 pump.
With a melling 10296 pump.
Wonder if the melling pump doesnt supply enough pressure for the VVT phaser?
11-01-2012, 02:28 PM
#16
Nothing except our exchange of ideas that both tune and scanner are in cam degrees, and my phaser limiter block may be slightly more restrictive, being in one of the 4 vane areas that are different than shown on the instruction sheet.
Not sure if you could check that theory at all with your test phaser? Degree the cam with the block in the pictured location, then again with the block in one of the other vane locations and see if there's a difference?
According to the CompCams instructions, I should have 22 crank degrees of rotation, or 11 cam degrees of rotation. I'm only seeing 7 cam degrees of rotation.
I haven't been able to do further testing because of the weather..
Not sure if you could check that theory at all with your test phaser? Degree the cam with the block in the pictured location, then again with the block in one of the other vane locations and see if there's a difference?
According to the CompCams instructions, I should have 22 crank degrees of rotation, or 11 cam degrees of rotation. I'm only seeing 7 cam degrees of rotation.
I haven't been able to do further testing because of the weather..
11-01-2012, 02:39 PM
#17
Is that ECM measured oil pressure, or gauge? I finally got my analog gauge hooked up and it also reads 45psi idle and 85psi high RPM (measured off the oil filter/cooler port) and the ECM is only measuring 25 to 50psi over the same range.
11-01-2012, 02:56 PM
#18
My car is torn apart again right now but I will do this ^ when i get it up and running again. Its nice to see that the values your logging are not actual degrees. Lots of things are like that in these ECM's though. I suppose HP or someone could create new definition files or whatever to translate these values respectively, but its also one of those things that once you know of, dont mind so much.
Another oddity I've noticed is I started logging "Intake Cam DC" which I take to mean the (D)uty-(C)ycle of the VVT solenoid for the PCM to control oil to the phaser.
The DC goes up to about 40% during a 6-7deg retard request which the cam follows, and 50% during a 8deg retard request which the cam stays at 7deg. But other times the DC sits at 35-38%, when the request is for 0deg retard.. It does go to 0% sometimes, but nothing in between 0-35% and nothing over 50% on the TSP limited retard tune.
11-01-2012, 02:56 PM
#19
Nothing except our exchange of ideas that both tune and scanner are in cam degrees, and my phaser limiter block may be slightly more restrictive, being in one of the 4 vane areas that are different than shown on the instruction sheet.
Not sure if you could check that theory at all with your test phaser? Degree the cam with the block in the pictured location, then again with the block in one of the other vane locations and see if there's a difference?
According to the CompCams instructions, I should have 22 crank degrees of rotation, or 11 cam degrees of rotation. I'm only seeing 7 cam degrees of rotation.
I haven't been able to do further testing because of the weather..
Not sure if you could check that theory at all with your test phaser? Degree the cam with the block in the pictured location, then again with the block in one of the other vane locations and see if there's a difference?
According to the CompCams instructions, I should have 22 crank degrees of rotation, or 11 cam degrees of rotation. I'm only seeing 7 cam degrees of rotation.
I haven't been able to do further testing because of the weather..
Do you know how the ECU determines the "0" position? Does it just determine that at startup while the phaser is in the advanced position?
11-01-2012, 03:09 PM
#20
The DC goes up to about 40% during a 6-7deg retard request which the cam follows, and 50% during a 8deg retard request which the cam stays at 7deg. But other times the DC sits at 35-38%, when the request is for 0deg retard.. It does go to 0% sometimes, but nothing in between 0-35% and nothing over 50% on the TSP limited retard tune.
