Tech Tip: IGNITION - TO HKS, ITS STAGE III:

by Michael Lee, Member@Large

Z enthusiasts often neglect one of the hottest components that hit the import performance scene.  Often, I would look upon a Race Ready Z or Street Performance Z and not see it.  Performance headers, large exhaust systems, air filters, and even cams; yet not what HKS lists as Stage III on their performance recipes for a majority of Japanese imports.

What is “it”?  An aftermarket ignition system.  If you remember awhile back I talked about how critical it was to choose the correct spark plug (?? Issue).  It can spell the difference between performance or sluggishness and in some cases if your motor will detonate.  Ignition systems become more critical with the earlier L-Series motors.

Recently I have started a 280ZX project, and following past experiences (more like addictions), I added a Nitrous Oxide System.  Immediately, I noticed a dramatic difference in misfires (and backfires from fuel loading).  This is not common for imports in general, but lets face it: Our beloved L-Series motors were well designed and blessed with impeccable bottom ends; but the test of time has weakened our stock ignitions or placed them out of date with today’s high performance upgrades.  In comes the aftermarket.

Today we have a wide variety of ignition systems available to us.  Mallory, MSD, Crane Cams, HKS, Jacobs, and Accel are just a few.  All claim a variety of gains, some more believable than others.  The reasons which opted me to install one are (1) Poor gas mileage; (2) Occasional misfires at high RPMs; (3) No Stock Rev Limiter; (4) Misfires under high compression (NOS, Turbo, Supercharger).

Dedicating a couple of hours, I installed a Crane Cams Hi-6 ignitions system with the complementing PS-92 Coil and upgraded wires (Stay with your stock NGK plugs +/- heat range changes for personal driving needs).  The Crane Hi-6 claims multiple spark discharge below 3000 rpm for complete combustion of the air/fuel mixture.  Above 3000 rpm, Crane claims a 500% stronger, hotter spark.

  Immediately I noticed an improvement throughout the RPM band, particularly above 3000 RPM.  Before, my car usually didn’t do much after 4500 RPM (besides make noise), but now with the ignition in place, the car was more willing to rev out further all the way to redline—an extra 1500 RPM.  In addition, I was able to increase the spark plug gap.  This is good for cars that have worn rings and oil blow-by, whereby a strong ignition will continue to fire through the oil dilution.  After about 3 weeks of notetaking, I noticed an improvement from 16.5 mpg average (before) to a 20 mpg average now on 87 pump gas.  My Nitrous system comes on strong with no hiccups and I have a rev limiter that is adjustable in seconds for autocrossing or street driving.

Overall, the car starts easier, idles better, and my G-Tech says there’s an average of over 4 hp.  0-60 mph with only an open element air filter and straight through exhaust yielded me 8.98 seconds.  On the Nitrous, I got 7.7 seconds.  With the ignition in place, my times improved to 8.65 and 6.75 seconds respectively.  As you can see, the nitrous times are better improved because of the higher probability of over-taxing the stock ignition system.

 But my mpg numbers are real world (no NOS) as well as the 4hp gain.  Seeing how I spend 90% of my driving under no nitrous conditions (okay, you caught me, would you believe 60%??), the 4 hp may not seem like much, but believe me—the car is more willing to rev higher.  And if that extra RPM in your power-band isn’t worth it, think of the 3.5 mpg gain.  That in itself pays for its cost with today’s rising gas prices.

If you have any questions, feel free to email me at car2nv@hotmail.com.  Happy Driving!