I've been searching all morning about ways to control timing advance/retard from in car, and have found a few options.


The MSD adjustable Timing Control, MSD box with timing control, holly anhilator setup, Jacobs product (forgot name)


Now, for the questions.


Is the MSD adjustable Timing Control able to be used with OUT a MSD box?

When searching on Summit, I see a couple of choices for the MSD one:

MSD-8680 Adjust your timing up to 15 degrees. Adjustable Timing Control $95.95
MSD-8681 Adjustable Timing Control $59.80
MSD-8682 Adjustable Timing Control $142.95

I'm assuming it's the 8680.

Will anything be required for this device? Or, should I look elsewhere to Jacobs/Holley/etc.


Just looking for some input, as I need a way to adjust timing on the go...

 

Are you looking for something to modify your current engine management system timing maps or for a complete system? I think (could be wrong here) that the Accel DFI systems and calibration software allow programming changes on the fly. Granted these are much more expensive then what you are looking at, they offer a much greater degree of tuneability.

I am not sure how MSD's add ons would advance or retard timing. Seems like it would be hard to determine without readouts and graphing where your problem is really occuring. Doubt this is much help to you, but maybe it will bring another response...

 

I'm just looking to adjust base timing....


I dont want to get too radical at this point with a DFI setup, or setups like the Holley Annihlator

 

If you don't plan on using an MSD-6Ax box, get their adjustable timing control, PN 8683. I've used this for years. Pic attached of mine but with a custom-made panel and ****. The numbers you see marked reflect my total timing at WOT, where it's most important. If you want specifics on how to wire and calibrate it (like my **** markings), ask and you shall receive!!

Willie

 

definitely interested in the notes/instructions you have

ben@fuelslut.com


Thanks!

 

Could you please post some of those instructions, or forward them to me. Thanks.
tharney@erols.com

 

First, some information on two MSD timing controllers. Both have the ability to advance/retard timing 15-degrees. The 8680 is used exclusively with their 5, 6, 7 or 8 box. The 8683 which I use, is designed to work with late model GM HEI ignitions. What MSD won't tell you is that this box can still be used if you decide at a later date to use their 5, 6, 7 or 8 box!! I'm proof of this as I now use the 6AL box with a Jacobs Ultra-Coil. The 8680 retails at $95.99 (Jegs) and the 8683 for $110.99 (Jegs again). Now, to the subject matter at hand.

I won't go into wiring specifics here but I will state the 8683 is very simple to wire. It splices into two of the four wires on the four-wire distributor connector and an ignition powered wire. That's it.

Once the module is wired and the **** is turned to full advance (clockwise to stop), your timing will be as it was before. Rotating CCW retards timing up to 15 degrees. These modules cannot advance timing. However, you can "trick" it to doing so. Here's how:

1)
Once the module is installed, rotate the **** fully CW. Leave the tan wire on TPI engines connected as you want the ECM to "see" the timing. Check your timing at idle with a timing light. Let's use 22 degrees at idle with the tan wire connected for an example.

2)
Verify that the timing module functions by rotating the **** ccw. Your timing should retard. Let's further assume you want to be able to advance your timing 10 degrees, leaving 5 degrees of retard available.

3)
Retard the timing 10 degrees (as seen with the light) with the ****. Temporarily mark the position of the **** pointer. By rotating the distributor, advance timing 10 degrees, thereby bringing the timing back to where it was before. Now, rotating the **** from its present position CCW allows 10 degrees of advance and 5 degrees of retard.

4)
Rotate the **** CW to the stop. Your timing should be 10 degrees advanced. Check this with the light.

5)
Rotate the **** CCW to the stop. Your timing should be 5 degrees retarded. Again, check this with the light.

I have found that the **** is not linear. Look at the pic I posted above and you'll see that the **** is linear in the center portion of its range and very "sensitive" towards either end.

Note)
Because this module is connected to the ECM output, a scanner will NOT show what the crank timing is, only what the ECM's output is. I have verified this with an Auto Xray and a timing light. To illustrate, I've connected both and watched the crank timing and scanner spark advance readout while rotating the ****. The crank timing changes (as it's supposed to), but the scanner readout remains the same. This is why I feel it's important to mark the **** gradations as accurately as possible. I did this by rotating the **** in two degree increments, verifying this at the crank, and marking the **** pointer.

Hope this helps.

Willie

 

Awesome. That's exacty what I was looking for..

I had the idea of tricking it like that to advance, but wasn't quite sure if it would work.


Thanks. :hail: