silvrevo

iTrader: (6)

Ya my pluggs were really messed up with using the octane booster stuff, maybe 2-3 times,,, I changed my pluggs out,,,,,, never gapped them ,, and the car felt alot stronger,,,,, alot.......

I would try to set your gap to what at least Shiv has said .28

Just my guess.

GR-VIII

I don't know if this will be relavent but here it is.
I had a 1990 Eclipse Turbo, similar engine to the EVO.
They car LOVED AC Delco Rapid Fire plugs (not Splitfire).
These are ungapable plugs. It was the only plug that had the proper color of
light chocolate brownish. No black deposits (dry black overly rich A/F mixture), no white specks (which can be caused by fuel additives), no blueish color (too hot in the combustion chamber).

The engine did NOT like platinum plugs, but that was then with a weaker ignition system. It did like the OEM NGK copper plugs. But, the BEST plug was the RapidFire.
After using them I never used anything else. They were a bit more money but they would last longer as well. The center electrode has lots of little cuts in it to create a lot of little sharp edges which is where spark like to jump from.
At that time (mid 90's) Napa carried them I believe.

I had replaced the OEM wires which were going bad with a few sets which kept popping off the plug. I would get bad idle at times and odd light power loss at top.
I finally get a nice set of 8mm wires from Taylor (I believe). They were blue.
Excellent wires, lower cost than Magnecore, and never a problem with them.

Bad plug wires are better found at night. That's when you can see any "arcing" that may be happening which will tell you that there is a break in the wire or boot insulation and the spark is grounding to the engine rather than firing in the combustion chamber.
Open the hood at night and fire up the engine. Then just look at the plug wires and note if you see any whitish or blueish or orangey sparks. A heavy leak can actually be heard as a crackle. Oddly, sometimes a bad plug wire will only show itself under load and not under idle. That sucks.
My thing is that if you've looked at everything else and it's fine, then it must be the obvious thing, change the wires.

The other thing that plagued my engine and others was proper torque on the plugs.
Those plugs would work their way loose sometimes just enough to cause a slight poor idle and some top end loss, probably due to some compression loss or erratic grounding of the plug to engine causing odd misfire.
Tighten those plugs nice an snug according to the proper manufacturer torque specs.
Check the torque on these especially new plugs as they tend to loosen till they settle in.

One more thing to note about top end and upper mid power loss in a turbo is the intake plumbing. I had a situation where idle was perfect and take up was was nice and solid. But, as I would approach redline there would be a "buck" or sometimes loss of noticeable power. It was the intercooler piping. It had worked it's way loose and would allow unmetered air in causing odd running.
A LOT of the intake plumbing needed to be kept up with on a regular basis just so you wouldn't have issues later. When you run higher boost and such, or even stock, these higher strung turbo engines need some love and attention.

I was only running about 16lbs of boost with a sweet 16G turbo. It was the proper turbo for that engine at that time.

BTW, what is the turbo that is used in the EVO? What does it flow?

TT