R500CDI vs Iridium/Platinum

[JanIvar]

Why cant we use Bosch/NGK/Denso Iridium/Platinium together with R500CDI?

[kristov]

What will happen if I run these spark plugs?

[-Totenkopf-]

Also interested, haven't heard about this though I have heard that runnign iridium/plat plugs is a waste of time, and due to their fragile nature can cause yuou some nasty issues if parts of the electrode come loose. I may have to run them for the time being though as I require a plug with a removable terminal and alot of the straight coppers don't have this (have a fixed moulded terminal).

[Kelly2264]

Bosch coppers (i.e. WR5DC) have a removable terminal...might look into the heat range you need.

[-Totenkopf-]

Bosch coppers (i.e. WR5DC) have a removable terminal...might look into the heat range you need.

Heat range 7 would be good (minimum). I'll see if I can source them near me. Thanks for the headsup.

I know of some heatrange 9 comp. plugs I can use, but these are not required for run in.

Cheers,

James.

[Wroom]

Common knowledge, or opinion, is that the plating of a platinum plug will degrade when used with CDI which outputs a much higher current for a shorter time than "normal" ignition systems. The old "blue vs yellow spark" debate continues...

Also, fine tip plugs, and iridium plugs are often pointed out (no pun intended ;) ) to become glowspots when used with high current ignitions, thereby causing knock.

And Bosch plugs with thin core of copper or silver has been deemed out for usage with CDI since the current is said to overheat the thin core.


Just to be thorough, i sent the question to NGK technical support.

Here's the full unedited answer, (except from removing email address to prevent spam):
Hello,

If you are currently using the B9EGP I don't see any reason why this
can't be used with a CDI ignition, unless the ignition manufacturer
specifies the use of a resistor plug to suppress electrical noise.

All NGK spark plugs are copper cored whether they are standard nickel,
platinum, or iridium and should work fine with CDI type ignition. Hope
this helps, thank you.

Best regards,



Brandon Peeler

Technical Support Representative

Aftermarket Division

NGK Spark Plugs (U.S.A.), INC.

46929 Magellan Dr.

Wixom, MI 48393Any comments? :cool:

[Kelly2264]

Interesting comment on the Bosch copper and silver plugs being "deemed out for usage with CDI". Some European manufactures have used CDI ignitions on stock vehicles since the '70s (at least) and they will go 30K-60k between plug changes without fail....just a thought.

[Wroom]

I guess that most often the plugs take blame when people have been desperately searching for a cause of some problems, and didn't find anything conclusive, but "solved" the problems by doing some different actions all at the same time just to get the car back running.

Therefore one must be careful with recommendations and rumours. But one must anyhow respect "common knowledge".

One interesting example is the Porsche 928S i got. Runs good on the Beru plugs recommended by Porsche. But Bosch plugs of the same configuration and heat range gets killed quickly. And NGK plugs can get fouled. Beats me why Beru plugs work so well on that car.

Maybe the best advice on plugs is: If you find a plug working very well in your application then stick to it.

Generally speaking i have had most success with NGK plugs. Bosch seems to foul easy. And Denso plugs don't hold together mechanically in a high performance engine.

[boosted]

I use brisk turbo racing spark plugs ,expencive but nice :)