What kind of gains do these give you and how much are they? Thanks

 

Zero gains and they're pricy. Irridium is a worse conductor than either copper or platinum it just lasts longer in the engine environment. They are suited much better for use in high boost applications.

Gabe

 

I'm guessing by high boost applications, you mean any form of forced induction? I just checked out a website that dynoed a 98 SH that already had a 75 shot of nitrous, AEM Pulleys, AEM CAI, and a Tanabe Exhaust. Gave about a 6 hp gain.

http://www.bottlefedracing.com/image...a_shl-dyno.jpg

 

Are you sure? I have always heard that the advantage to iridium plugs is that they have the longevity of platinum AND conduct better....but copper still conducts the best.

 

Then do what I do, spend 10$ every 10k miles, with NGK copper plugs that are called for a H23a.. Best performance

 

I could be wrong about the conduction difference between irridium and platinum, I'd have to check on that to be sure. That was pulled up from memory and it's been a while since I've looked into it.

I have to agree with Corey, I use NGK coppers. They're cheap and dependable.

Gabe

 

Yeah, just use copper. I would say that any gains seen are just from replacing worn plugs with new ones, not because they might be iridium.

 

I have bosch +4 they are between. Good cheap ones not expensive and a different design. Not good for Nitrous apps. tho. they are too hot oh well.

Denso are too priecy for me.

 

Put down the densos and walk away very fast! I had them in my car for a couple of months. The car started to run like ****. I yanked the plugs, and the electrodes were eaten to ****. Waste of $40+. Now I just have some good ol'e NGK in the H22.

 

Subject: Denso Iridium Race plugs VS Bosch Platinum #4227

The Denso sells for $60+ a set and lasts a long long time.

The Bosch #4227 platinum sells for about $8 a set and lasts a long, long time.

The blue line is the Denso. Look how close it is!! What a race!

Take it for what it is...same car, back to back runs...several runs on each plug...and its NOT the best run vs. the worst run...its an average...and
consistently, the Denso showed SLIGHT improvement. As in SLIGHT.

Thanks to Jeff from importreview.com (importbuilders.com)

Note: I am more in favor of NGK - all the way!

 

doesn't NGK make an Iridium plug?

 

I was going to buy the Denso Iridium for $50.00/set but I know I have read about it and it doesn't seem to perform as much...

 

The Bosch +4 suck, The Denso Iridiums made my car more responsive.