yanked the plugs on the new to me S & it appears they are near the EOL, not burning so hot. So, going to swap them out, what was in there was a BRE7EQUP., What I had on hand (from the search I did) was a BRE7EIX. Mods are a 15% pulley & MSD coil + unknown wires.

Price wise they are the same. Question is, which is the preferred plug by the community for the mods this car has?

One of the plugs was coated in oil so I assume I have a valve cover gasket on my plate in the near future... and... one of the wires was not seated on the plug tip. jeeze... wonder what else I'm gonna find...

What I've done so far (time limited) is to clean the dinan intake filter and swap in a vibratec (?) motor mount. Goal is to make it a solid DD, dont need a lot of HP or TQ, just the right amount to make me happy. It will never see the track and it will share duty with the Ram (441k miles...ouch, but still runs like it'll live for ever).

 

Definitely the BRE7EIX plugs since you have a 15% pulley.

 

the iridium plug is a better choice over the BRE7EQUP then? I dont recall what the counter guy said that plugs material was made of.

 

In my opinion, yes. It's what I run on my R53 with a 15% pulley and I've had no issues with them whatsoever.

 

roger that, thanks!

 

Interesting.... that BRE7EQUP Plug is the same NGK BRE7EQUP as used in the 2000 - 2003 BMW M5.

 

The counter guy @ auto parts store said his bmw used that same qup plug... swapped in the ones I had on hand, ran better on the short drive I went on.

 

I perfer the 4 prong ngk. Never loses gapping and ive ran them on my modded engine now for awhile with absolutely 0 issues.. i don't know why the 4 prong ones arnt referred more.
NGK Platinum BKR7EQUP is what I'm running.

 

I have no idea how long those were in there, but they were definitely done. new set runs as expected... awesome. With mine seeing backup duties to the ram, may be awhile before the next set is due.

 

iirc the NGK BKR7EQUP is what came stock in the JCW cars. I pulled those out of my car running a 15% pulley after 40k miles since install and swapped them out with another set of the same. I torqued them to the upper limit of the spec and re-check occasionally to avoid the all to common spark plug blow out.