Timing Curves

[BPWilliams]

I just purchased a MSD-8979 programmable timing box for the green machine. I am hoping that by locking out my distributor it does not grenade on me passing truckers in the middle of nowhere.

OK, the big question is about timing curves and because this hooks up to my laptop I now have almost endless options on my timing settings. I was wondering if anybody has any knowledge of this box and can recommend curve settings, here are the vitals

429 SCJ
14 degrees initial (would like to run lower to keep it cooler, say 10deg?)
38 degrees total
440 rwhp
my solid cower cam kicks in at 2.8K and my current curve is all in between 1K and 2.8K. no start retard.

I have options for start retard, and retard on RPM drop (shifting), I mostly use the car for long trips, or racing.

Any help would be appreciated!

[mikiec]

The best recommendation I can give you.... SB.

Hope to see you and Barb out and about soon.

Mike

[HighPlainsDrifter]

Hi,
14* initial is perfect, if you retard the initial and low rpm timing it actually makes the engine run hotter, that's what the factory did by retarding the cam 8* to pass emissioms.
As for total advance, 38 is good for 9:0 to 1 motors, if your 10.5 to 1 maybe go to 34* total.
Good luck,
Perry.
btw- I'm now a retired snowbird and will be at queen creek and power on and off during the winter, thinking of bringing the cobra down for some rare winter driving

[Karl Bebout]

Perry, congrats on the retirement thing. I'm liking it a lot. Bring your car on down and enjoy the winter time driving. You'll be pretty close to the Saturday night cruise in at Power and Hampton (close to Southern Ave) This time of year, there are usually only about 100 or so cars but when the temperatures lower, many times there are 200 or more.

[BPWilliams]

High planes,
Thanks for the info, I have 11 to 1 custom JE pistons and currently have 38deg total. The car actually runs great with the current set up and I was just considering transfering the settings to the electronic MSD box.

I heard somewhere that you actually want to remove some timing at the high end to increase HP and torque do you know if this is true? So what I was thinking was this:

start @ 10deg (timed)
Initial @ 14 deg
1000rpm to 2800rpm ramp a straight timing curve to 38deg.
6000rmp to 7000rpm curve to 34 deg.

If my compression is at 11 to 1 with aluminum heads I still should be able to pull the 38deg I think, there is currently no pinging or predetonation along the curve. I have noticed that @ 6300ish rpm the HP/Torque starts to curve downward.....

[dlampe]

I think 38 deg. is a little high. If you have really good heads, the timing could be lower to reach optimum HP and TQ. I know from experience that in a cobra you will not hear detonation or pinging. In a well built race engine 32 -34 deg. is usually enough. As the head quality moves down the continum, the timing will need to be bumped up. Timing can be very hard on an engine and I only picked up a little more power bumping the timng. I also run a locked out dizzy all the time. It is set at 32 deg. That is where I make the most power.

[HighPlainsDrifter]

Hi,
It looks like a good plan. It probably works good like this because the MSD actually can runabout 2 to 4* more advance than you would think.
The top end retard is good also,not as hard on the rods.
I would pull the plugs and check for detonation ocasionally. Instead of tan the plugs will have a yellowish spot or actuall start burning the electrode off. If the plugs read OK I think you are set.
Perry.