[jim_howard_pdx]

Speed Secret Number 6

If you want to pitch for the Angels, you had better have a good curve ball!

To get maximum torque and power, you had better run an optimized ignition curve!

Nothing and I do mean NOTHING can help your engine if your burn event is mis-timed or incomplete. NOTHING else matters in the quest for power than getting your compressed mixture to pre ignite, and establish a flame that propogates from the center of the cylinder to the edges of the piston.

THIS IS WHERE THE POWER IS MADE.

So what starts this event. VOLTAGE.

First off, you should be running racing plugs or at a minimum, a high performance plug. What do racing plugs offer???? They are built to take high cylinder pressure events. Stock plugs are built for 2,500 rpm and 100,000 miles of use. Racing plugs are designed to deliver voltage when the car is at maximum torque under load. Things get hot, intense, and down right nasty. Your plug needs to be designed to take all this and LAUGH while it says "IS THIS ALL YOU'VE GOT?"

Do you need platinum or iridium?----NO. Do you need a weird multi electrode model?----NO.

I buy the NGK Racing plug. I bend the grounding electrode end out and use a cutting wheel to notch a V in the tip. This is an old NASCAR modification. When the spark fires, the kernal extends into the combustion chamber instead of just being limited to either side of the center electrode or the grounding electrode.

Then I bend it back to .045 to .055 gap. I usually have a minimum of 55,000 volts, and the longer the spark gap is, the more air/fuel it is exposed to when the voltage crosses the gap.

Next, you should run fresh wires anytime you suspect the wire is getting cooked. I use spiral core ignition wires for ALL COMPUTER CONTROLLED CARS, and ALL MULTIPLE SPARK IGNITION BOXES. I use solid core copper for NON COMPUTER, NON STEREO CARS. Do not use carbon core wires on any high performance application. The resistance is ok, but the carbon has weird inductance and conductance factors that effect your HP in strange and interesting ways. Also, never run a solid core wire on a computer controlled engine. You will have strange and weird things happen.

Run a fresh cap and rotor with brass posts.

I like MSD and Crane Hi-6 boxes. Most high performance engines find it easier to fire the mixture when they are up in revolutions. But ignition quality suffers during low rpm driving. So a multiple spark ignition fires that cylinder 6 times per power stroke up to 1500-2000 rpm where the engine really needs the extra help.

Use a great coil. I like the ones sealed within epoxy, since they take high vibration environments really well.

Have a competent race shop outline the best possible curve for your drivetrain configuration. Your ignition curve should be different for a 3.0 rear end ratio than for a 4.88 rear end.

On my 358, I start out with 12-14 degrees initial advance, with a total mechanical advance of 32 degrees. The advance is slow and steady from an intial advance that includes the vacume of 12-14 degrees, and provides a maximum of 42-44 degrees all in by 3,000 RPM's. Under load the engine never sees more than 32, but when cruising on the freeway with very lean part throttle mixtures, the engine runs a lot cooler with the 42-44 degrees.

You can re-curve your distributors yourself, I just did mine showing my son how to completely disassemble and put it all back together. Just get a shop manual and a recurve kit for your application. When disassembling the distributor check the bearing for wear. If the shaft rattles inside the bearings, get a rebuild or a blueprinted stock unit, or step up to a billet high performance unit.

If you have points, these have got to go! It is time to go with a magnetic trigger and an ignition box. Check with your motorsport dealer for suggestions on your applications and have them outline two or three options.

I chose a durospark distributor, (rebuilt unit 26.00). Then I tore it apart, made some changes, changed the curve springs and I have a great setup with only about 40.00 invested. You can pay up to 250 dollars or more for a billet unit, but it generally will not make a substantial difference over a well built durospark unit.

On my duraspark unit, the distributor has a 15 degree stop or a 20 degree stop. I had to switch mine around to set it at 15 degrees. Make sure you or your shop works to establish a hard stop where the ignition cannot advance beyond the 32 degrees when under load. This is an important safeguard to reduce or eliminate detonation.

Finally, some race engines with hi test racing fuels can take more advance curve. So be willing to experiment. Never judge by the seat of the pants feels. If it does not improve your times, then set it where it get the very fastest times you can achieve. I have seen people recurve their distributor to a "book value" or "recommended value" and lose et time. What good is that?????

When you finish with the ignition curve, NOW you can go ahead and set up the carb or fuel injection. Remember the IGNITION CURVE MUST COME FIRST when power tuning!!!!

So read up on this, ask a couple of shops for their feelings and recommendations, buy a recurve kit, a manual, and take some time to play. You will be surprised with faster et times when you optimize the correct curve for your application.

I am certain to get into more detail with the NOS crowd and Super or Turbo charged engines, so please read through the discussion.

Let me know what works for you, and outline your cubic inches, cam, compression ratio, rear gear, and how it ran before and after. Let everyone who reads know what you have experienced with a properly curved engine.....

I will tell you one thing, on many an engine, a static curve will hurt potential et. So with computer controlled cars it is possible to dial in specific advance by the rpm and load condition of the engine. This lets you get everything possible out of your powerplant. Let me know if any of you are running this type of custom optimized computer modulated curve. They really can help you win a bunch of races.

Yes a wicked curve will beat your competitor. I promise you that it will be worth your effort to get this dead on correct.