Hey Guys! Move complete....ish. I am now at a point where I want to get started on refining (or ... um... understanding) the timing a bit more.
OK so to recap, I have a brand new Pro Billet MSD distributor installed and its Locked out since I will be using the FiTech system for timing control. The following values are what the systems asks for as far as timing. I have filled in the values as they told me based on an base timing of 12 degrees (I think on a earlier post we have decided to up that to 16-18 degrees) and an all in timing of 30 degrees:
*Distributor Base Timing: 10 degrees (I double checked on this and the tech said 10!) Also re-read Ross's Post, but I don't think I am fully understanding why 10 LOL Since you have to check timing at a high RPM because the timing jumps around at lower RPM's due to the computer control, I don't know how I could adjust using this field when the low RPM number moves around. Maybe I am totally off. I understand the concept Ross described, but the moving timing number (at low RPM) throws me.
*Idle Advance: 12 degrees (I think this will need to be changed to 16 degrees)
*1100 45kPa: 25 degrees
*3000 45kPa Cruise: 30 Degrees
*6000 45kPa: 30 Degrees
*WOT 1100 95kPa: 25 Degrees
*WOT 3000 95kPa: 30 Degrees
*WOT 6000 95kPa: 30 Degrees
Followed by this excerpt:
SPARK MAP: The spark advance uses a 3x3 matrix table to allow flexible spark advance control. This can allow distributor simulation, locked timing, boost retards, high RPM advancing and other strategies to optimize the ignition spark advance angle. The distributor must be locked out. Spark advance during cranking will happen at or after the VR tooth crosses the sensor. Above cranking, spark advance will only be equal to or more than the base advance, regardless of the value entered in the handheld for timing. Distrib Base deg = Adjust this to get the timing light timing to match the displayed Spark Advance at low RPM. It’s recommended to set this as high as possible, because the amount of advance range from min to max is limited due to the rotor and cap being in a fixed relationship. VR Advance 4000 = Adjust this to get the timing light timing to match the displayed Spark Advance at 4000 RPM. This is adjustment for the small lag inherent in VR signals. It can add up at high RPM. Idle Advance = The spark advance desired at idle. 1100 45kPa = Spark advance used just after throttle opens from idle. This value shouldn’t be much more than the Idle Advance, for this reason. 3000 45kPa Cruise = Spark Advance used in a light cruise at 3000 RPM and throttle barely open. 6000 45kPa = Spark Advance used in a high free-rev condition, perhaps also seen when autocrossing and just tipping-in in a low gear at high RPM. WOT 1100 95kPa = Spark Advance at low RPM and “full load” – perhaps the throttle is as low as 20% to see this much load. Spark is based on MAP, and MAP (and thus “load”) can get pretty high even with low throttle openings at low RPMs. WOT 3000 95kPa = Spark Advance at high loads and 3000 RPM. This could easily be deemed “total” timing when comparing to a distributor, but due to the flexibility of a 3x3 matrix, this doesn’t limit you as such. Handheld Controller Feature Definitions 4 WOT 6000 95kPa = Spark Advance at high loads and 6000 RPM. At high RPM, some engines require more or less spark advance than at 3000 RPM. This allows you to set the timing there. Boost 1100 180kPa = This is full throttle but with a supercharger or turbocharger boosting to about 11.6 psi. If no intercooler is used, the engine may require very little spark advance. Remember that timing less than the base advance “Distr Base Deg” is not allowed, so choose the base timing carefully. Boost 3000 180kPa = This is full throttle but with a supercharger or turbocharger boosting to about 11.6 psi. If no intercooler is used, the engine may require very little spark advance. Remember that timing less than the base advance “Distr Base Deg” is not allowed, so choose the base timing carefully. Boost 6000 180kPa = This is full throttle but with a supercharger or turbocharger boosting to about 11.6 psi. If no intercooler is used, the engine may require very little spark advance. Remember that timing less than the base advance “Distr Base Deg” is not allowed, so choose the base timing carefully.
So I guess I want to know a few things:
- First, that 10 Degrees at Base timing. If my Idle timing was 12 degrees (soon to be 16 degrees), what is the 10 Degree Base? Is it a degree of timing just used for cranking the engine over? And then when it starts, it does to the Idle Advance value?
-Second, in the excerpt above, it says that 1100 95kPa should not be far off from the Idle Advance- "Spark advance used just after throttle opens from idle. This value shouldn’t be much more than the Idle Advance, for this reason." Doesn't 25 degrees seem far off from the 12 degrees of Idle Advance?
-Third, when I change the Idle Advance to 16 Degrees as suggested earlier, what should I change all of the other values to? I know I need not go over 30 Degrees Total timing, so with that in mind....?
- Fourth, it does not seem like after I change the Idle Advance to a Value of 16 Degrees that I will be able to accurately check it with a timing light (since the computer is constantly adjusting-According to the tech). I need to check timing with the timing light at 3000 or 4000 RPM's (since that should be steady) and then as long as the value I see on the balancer matches the 30 degrees total timing, in theory when I let off the throttle, the computer will control the timing to ensure the idle advance value of 16 degrees is met. Does this sound correct?