pabound

Hey, has anyone taken the time to change the plugs in their TL?

Just purchased a set of iridium's, to see if they can halp in either the mileage or HP category, in addition to my new AEM CAI.

Looking at the engine, I see that the back 3 plugs are perfectly centered UNDER the strut tower brace - in essense blocking any reasonable attempt to change them...

PLEASE tell me it ain't so...

Any ideas?

Thanks

Road Rage

I have lots of ideas - what's the question?

1) Iridium (plural is iridia) plugs have their place, but I would not look for signficant HP gains. I actually tested in our lab all sorts of plugs, and found that the biggest advantage of Denso's designs is in a significant reduction in misfires. Over sustained high RPM use, it could make a fraction of a second difference - improtant for racing, but not for the street.

2) I went with the Densor Iridium in my S2000, but went one range colder. This helps reduce loss of power, since Hondas dial back their spark maps quite a bit in hot temps. In addition to that, I went with a Mugen 170 deg thermostat (not too hot, not too cold) and a Mugen fan switch to match it. This again helps keep the car from losing power. The 3rd element was a lot of work - installing a Honddata engine to intake runner gasket - this greatly reduces the biggest cause of heat to the intake air charge, reducing inlet temps in hot climates by a measured 50degF!!! All this was measured using my AutopXray 6000 and a clabibrated thermocouple/thermometer.

3) I may be wrong, but doiesn't the TL already come with a small electrode plug? If so, do not expect any noticeable pereformance gains, unless yu got he route I did.

4) Note that we say similar reductions in misfires when using regular copper style Denso's like the TR6, for example (in the supercharged Cobra). These copper type plugs use similar u-channel ground conductor architecture - it seems to be that mroe than anything that allows the reduction in misfires, but allowing the spark kernel to find its ground in multiple spots, or at least always 1 good one. These plugs provide similar performance for 1/10 the price, but probably do not last as long. Replacing plugs on the Cobra is pretty easy, so that is what I did their.

Here are some ol' RR tips and tricks fpr plug installation:

1) Loosen the hardest one first - no use going 5 and finding you cannot get the 6th.

2) Use some marine or high temp (copper) style anti-seize on the threads - just a small amount - too much and you can actually short the plug.

3) I have all sorts of spark plug tricks and tools: u-joints, locking extensions from Wright tool (love 'em), etc. Loosening the plugs is one thing, but the great risk on aluminum heads is cross-threading. What I have always used is a short length of 3/8" automobile coolant line hose. It is flexible and stable enough to hold the plug, but will start to slip if you are cross threading - a real head saver! and knuckle saver as well!

4) Only work on a cool engine

5) I can set a plug by feel, but if you are not an experienced wrench, use an accurate, beam style torque wrench if possible. Allow that the ASeize will affect the torque reading by reducing about 1-2 pounds, so make sure you do not undertorque. I like to recheck in about 500 miles if possible on the S2000.