timing???
Why would you start with a zeroed out timing table? The best way I know how to deal with timing is to get on a dyno and see where your car makes the most power. Typically, adding 3-4* to WOT is where people find peak power. If you don't have the time/money for a dyno, make small changes to your file and see how the car reacts on the butt dyno. Just watch out for KR. The stock table should be fine to start from. If you're running a cam, then timing may need to be adjusted to smooth the idle. But, I wouldn't start from zero. If you see KR in the stock table, back it off some. I noticed this mainly in the mid-low RPMs with a significant load on the motor (uphill, 4th gear, < 2000RPM).
I'm not going to start from zero, and I know to bump timing until KR, then back off a little. But what I don't understand is the timing for idle, etc. On howstuffworks.com says you need little to no timing down low, somthing to do with the camshaft not spinning so fast or something, and I was just curious if anyone knows how to derive a table from scratch.
I'm a fan of the "jack it forward until something
complains" method.
You don't "need" a lot of timing at idle but the
more you have, the more responsive the engine
will be to roll-on of airflow (minimizing stumble /
bog, and minimizing IAC loop surge). Leading the
target, so to speak.
For WOT I think the best way is, get your mixture
to a believed-good place, and bracket it with
2-degree steps up while monitoring both KR and
some quantitative performance measure (like time
from MPH to MPH, or whatever). Performance will
improve with timing to some point, then a "flat top"
and then ping. Position yourself back a few degrees
into the flat-top, the best position is the one that
cares the least about a bit more or less.
Then you might fiddle fuel about that point, pick a
good setting there, and repeat the whole exercise
until it stops paying off.
complains" method.
You don't "need" a lot of timing at idle but the
more you have, the more responsive the engine
will be to roll-on of airflow (minimizing stumble /
bog, and minimizing IAC loop surge). Leading the
target, so to speak.
For WOT I think the best way is, get your mixture
to a believed-good place, and bracket it with
2-degree steps up while monitoring both KR and
some quantitative performance measure (like time
from MPH to MPH, or whatever). Performance will
improve with timing to some point, then a "flat top"
and then ping. Position yourself back a few degrees
into the flat-top, the best position is the one that
cares the least about a bit more or less.
Then you might fiddle fuel about that point, pick a
good setting there, and repeat the whole exercise
until it stops paying off.
So how do you determine how many degrees part throttle/idle timing to do? What if you put 100 degrees? Sorry to sound dumb, just trying to get better grasp. What if I start with all zeroes and start building table?
Launching!
Joined: May 2004
Posts: 292
Likes: 0
From: On a mountain with snow
The best way is to take your original 2001 Camaro timing table and start tweaking it. After all, the General is the expert on your car and has it dialed in pretty well, although a touch on the conservative side for obvious reasons.
The General sets things up to the "least common
denominator" (or, "least money spent on warranty
service"). Timing is well less than maximized in the
interest of not seeing a million customers come back
whining about knock.
I'd start with adding 6 degrees across the board, to
the stock HO timing table. Predator gets away with
that, in their "Install Performance" tune. Presuming
stock hardware. The hotter/ heavier the charge, the
less timing you need/want/tolerate.
You have to throw a stone, and watch the ripples.
denominator" (or, "least money spent on warranty
service"). Timing is well less than maximized in the
interest of not seeing a million customers come back
whining about knock.
I'd start with adding 6 degrees across the board, to
the stock HO timing table. Predator gets away with
that, in their "Install Performance" tune. Presuming
stock hardware. The hotter/ heavier the charge, the
less timing you need/want/tolerate.
You have to throw a stone, and watch the ripples.
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My stock table doesn't like the General's timing below 3600 RPMs in higher load situations. On a stock table, I've seen up to 4.X* KR while the torque converter is locked in 4th @ 1600-1800 RPMs. If you were going to adjust the timing, I wouldn't add anything below 3600RPMs based on my experience. Even though every car is different, why even bother when you're below 3600RPMs for all of about 1-2 seconds in the 1/4 mile?
Launching!
Joined: May 2004
Posts: 292
Likes: 0
From: On a mountain with snow
Could be false knock, burst knock or too lean of mixture down low causing the KR.
Knew you guys would rip the General's timing. Reverse engineering what they already know isn't being smarter then them. My point was it was better to start with the stock timing than all zeros.
Knew you guys would rip the General's timing. Reverse engineering what they already know isn't being smarter then them. My point was it was better to start with the stock timing than all zeros.
how does timing stress the motor? I don't fully understand timing, I guess is where this post comes from. I mean, I don't understand why (Stock table) some timing values are 0, others are 23, etc.
