carlos_hiraoka

Does anyone know upto how much power is the stock WRX ignition good for ?????

This is a message poted on the i-club list:

" ..... WRXRob is right. Most stock ignition systems often prove to be less-than-ideal at higher power levels. For examples, Miata ignition systems usually start to break-up above 11psi and totally go into the toilet at 14psi. As a result, hp is usually limited to 225-245 wheel hp. RX-7 twin turbos usually break up around the 300 wheel hp mark. The EJ25's ignition usually falls apart above 240 wheel hp. SR20s usually sees problems above 250 wheel hp. And so on...

Making matters worse for these ignition systems is the use of regular pump gas. This requires quite a bit of timing retard. What timing retard does is initiates the spark later in the compression cycle. And the later it is initiated, the latter it fires. And the later it fires, the higher the cylinder pressures. And the higher the cylinder pressures, the harder it is for the spark to bridge the gap. Throw in a lot of fuel (necessary for engine cooling in octane limited situations), and the workload on the ignition system is harder. Then throw in a bigger turbo which shifts the torque curve up higher into the revband, and now the ignition is forced to work with less time for coil charging between engine events.

At the end, one is often left with an ignition system which is at the edge of its capacity. One that is very unwilling to operate consistantly out of a narrow window of allowable advance, a/f ratio, boost, rpm, etc,. Almost always, the user is forced to run fuel and timing values that are less-than-ideal for power and long-term durability.

While misfire isn't nearly as bad as detonation to the health of the motor, it often tends to *induce* detonation if the conditions are right. When misfire occurs, there are volatile end gases that go unburnt. And when exhaust back-pressure is high, these end gases don't evacuate the combustion chamber and tend to pre-ignite. At least this has been my findings in several situations.

My 2c,
shiv ..... "

also check out:

carlos_hiraoka

no comments guys ..... ?????

CHG

carlos_hiraoka

.....

CHG

R19KET

Carlos,

Apart from using a colder plug, correct plug gap, and the plugs, leads, etc' are in good condition, the standard ignition systems used on the STi/WRX are fine.

Mark.

carlos_hiraoka

..... thanx ..... and what is the correct plug gap ?

CHG

Bob Rawle

0.7/0.8mm

MY92-96 cars use coil packs, these can be prone to not producing enough spark once boost is raised (or even when its not). Later cars rarely have problems even at highish boost levels, factory fit spark leads are better than the aftermarket ones so stick with whats there..

I managed to overcome coil pack issues using a Motec on my early car, as soon as I took it out it was obvious they had gone. Symptoms are misfiring and shuddering, can also make the car feel as if its hesitating when its "mild".