Better spark plug than a BOSCH W3DPO for a stock 3.3L?
 

I have to change plugs, and for a car driven on the street, is there any plug better than the plat Bosch W3DPO?

I know there are other plugs that MAY work in this engine, but this plug was designed for the high-heat of that 3.3L turbo motor. Just like oil, technology has marched on since the 3.3L debuted.

Feedback or results would be great...thanks.

For a street car a little hotter plug works better. I've had luck with NKG BCPR6ET or Bosch FR6DTC. Finding them is another story ...

I guess there's alot of them that will work. Plain old cheap copper core bosch W5DC probably work good but I've never tried them in this car. My car had the 3dpo plugs in it when I got it and they worked fine. I still have them but they're not in the car.

Long time ago someone recommended Bosch W4CS plugs on the forums. It's a silver tipped plug I think and pelican sells them so I bought 6 of them around 7 years ago and have been using the same set since. They work great.

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I'm running Bosch FR5DTC in my twin plugged 930. Get them from Rock Auto for $2 and change a piece.

ngk bp 8es

Upper Beru 14 FR-6
Lower NGK D8EV

Ditto....though on second thought I might have 7es in there, a tad hotter than the 8es, but I don't remember to be honest. Messed with both heat ranges and settled on one that I liked best some time ago.

I've run NGK B8ES in all my 2 stroke air cooled dirt bikes for over 40 years. They handle those extremes very well,

The NKG BP8ES is equivalent to the Bosch W3DPO.

I am all for running the colder plug in our high compression engines and turbo ones too.
You can do some research and find the combustion chamber temperature difference from one heat range to another. It is a bunch. We run the coldest plug possible to gain a little insurance and safety margin since turbo engines have a bad reputation for detonation. So taking all things into consideration with timing and boost levels plus a smart tune, including plug reading, I would like to see our engines live. This heat range chart might be a good reference.

http://forums.pelicanparts.com/uploa...1372130353.jpg

The NGK BP_ES series is a standard copper core plug that is the equivelent of the Bosch W_DC series. If they are resistor plugs there is an R in the part number.

The NGK BP7ES is the equivelent of a bosch W5DC. Bosch doesn't make an equivelent to the NGK BP8ES I can find and if they did it would be a W4DC. Maybe special order but not on common lists.

The Bosch 3DPO is non extended tip, sideways firing platinum plug that uses more platinum than than the less expensive common extended tip platinum plugs you can buy anywhere. There is no NGK equivelent design to the 3dpo I've seen. Maybe heat range equivelent but not in electrode design.

yeah i know... more boring blah blah...

Nice chart above... I didn't see that before I started my post.
According to that the 3dpo equivelent heat range in the NGK series would have a 9 in the part number.
My car always ran fine with the 3dpo's and never fouled them. They're just expensive and other cheaper plugs seem to work just as well for street driving.

Many plug numbers are no longer available as companies have consolidated them into groups. Numbers that come up when you cross reference are not necessarily an identical match but very close.
Your environment should be taken into consideration when choosing a plug for the 930. The cold W3DPO will work better to reduce knock in a very hot climate and a hotter plug will work better to resist fowling in a more mild climate. For track cars a cold plug is better.

the best plugs I ever ran in my 930 were the base autolite copper plugs. dirt cheap and lasted 30k+ miles. I would notice a drop in performance with ngks after 10-15k and forget the bosch's, my car would fowl those out after 2-3k. just my .02

I've had good luck with Denso Iridium IW24's.

If you have a good MSD ignition, cheap NGK BP8ES or BP9ES work fine.