Well I just installed my new NGK Iridium plugs today. Car runs much smoother, a bit better acceleration, and gas isn't used as much. Everything is great but I have one concern. When I rev the engine up to the rev limiter, I hear something that sounds like bolts moving around and hitting each other...keep in mind that I know theres no bolts actually moving around, this is just what I'm comparing the sound to.

 

the car is telling u not to do that.lol

 

i agree to that lol

 

where do you hear it coming from??? front, rear, passenger, driver, middle, tranny, motor, where damn you!?!?!? LOL

 

That sound your hearing when you hit the rev limiter is called the rev limiter....

 

It is telling you that if you keep that up you're going to be picking up nuts and bolts from under your car.

 

Do you notice that much of a difference from the stock plugs?

I hear that you feel almost no performance gain with wires.

 

Ies I did actually. It also depends on the quality of wires. My friend has a 05 SXT manual and when he changed his stock plugs and wires (to MSD 8.5 MM superconductors and NGK Iridium plugs) even I could tell the difference. He told me that he was driving through his neighborhood and tapped the gas like normal and he was suddenly up to 50 mph. I could tell he shifted faster and got up to speed quicker too. I'm not saying its a huge difference, but it is noticable.

 

No performance gains from spark plug wires...only a smoother idle. The plugs might give a slight gain, but nothing that would show up on a dyno or that you would actually feel. The "gain" that you and your friend felt was purely psychological in nature...same thing that happens when you install a CAI or STH, they really dont give much gain at all, but people think they do...

 

When you consider you might get an extra 5 or 10 horse power, it seems insignificant but it's really a big deal. When you only have 130 or so horse power, 5 extra is a 3.8% increase. The MSD wires have a lot less resistance and put more power to the plug, which burns the fuel more efficiently. If better wires and plugs didn't help, I'm sure racing companies would get the cheap ones from wal-mart.