[Snaggletooth]

I was curious as to what temp range and gap you guys with 15+ PSI are running. Any plug recommendations?

Also, do you guys index your plugs? If so, do you aim them towards intake or exhaust? I am kinda unsure where the car would be happier cause of the direct injection.

I'm curious to see if this helps some of the misfires as well.

[Allaboutthehype]

I run the OEM BMW plugs (Pre-gapped) and change them out about every 25k. Maybe a little crazy but I run 18+ psi with E85 and it keeps my car happy

[135Pats]

I wouldnt worry too much about colder plugs on stock turbos.

[JStang]

Originally Posted by Wicked335i

I run the OEM BMW plugs (Pre-gapped) and change them out about every 25k. Maybe a little crazy but I run 18+ psi with E85 and it keeps my car happy

+1

[Lux3m35i]

Definitely OEM plugs. Turbo engines are sensitive when it comes to the ignition system. OEM plugs do have the correct characteristics and are proven for the engine. Just make sure that you change them earlier when running a tune.

[N8N]

Damn, that's a legitimately good question, and I don't know the answer to it. I have no idea what the optimal indexing would be on a DI engine. However, seeing that these are multi-electrode plugs, I wouldn't worry about it too much - one electrode can't possibly be more than 60 degrees off of optimal even if you just slap them in without any regard at all to indexing; at the same time, you can't tell which electrode is going to fire during any given combustion event.

If you don't like paying the money for OEM plugs there is a Bosch equivalent that is indistinguishable. Don't have the part number handy but you should be able to find it with a quick search.

[E90Company]

OEM is fine. Some use re-gapped NGK's and have had sucess.

[j1gilles]

Go with the OEM plugs.... Indexing plugs is more for top fuel dragsters and the OEM plugs use a 4 prong electrode so indexing is not needed. Colder plugs are not needed unless you are running upgraded turbos and they tend to foul at a much faster rate.

[Snaggletooth]

Originally Posted by j1gilles

Go with the OEM plugs.... Indexing plugs is more for top fuel dragsters and the OEM plugs use a 4 prong electrode so indexing is not needed. Colder plugs are not needed unless you are running upgraded turbos and they tend to foul at a much faster rate.

That's the reason I ask.. I'm gonna be running some hybrids soon at around ~18 or so PSI. How cold would you guys go in this case?

[j1gilles]

Originally Posted by Snaggletooth

That's the reason I ask.. I'm gonna be running some hybrids soon at around ~18 or so PSI. How cold would you guys go in this case?

On my GN I went one step colder but I was pushing 20+ PSI. Im not an expert on these cars but I think this plug question is personal preference. Some people stick with OEM with hybrids, others go with the NGK one step colder.

[Alexm007]

Originally Posted by N8N

Damn, that's a legitimately good question, and I don't know the answer to it. I have no idea what the optimal indexing would be on a DI engine. However, seeing that these are multi-electrode plugs, I wouldn't worry about it too much - one electrode can't possibly be more than 60 degrees off of optimal even if you just slap them in without any regard at all to indexing; at the same time, you can't tell which electrode is going to fire during any given combustion event.

If you don't like paying the money for OEM plugs there is a Bosch equivalent that is indistinguishable. Don't have the part number handy but you should be able to find it with a quick search.

IIRC My 2007 N54 uses Bosch (#ZGR6STE2) Best prices from Amazon, ECS tuning, etc. Sometimes sets of 6 cost more than 6 individuals, so be careful!

Alex

[AndyR83]

I changed my plugs yesterday. I am running NGK 5992's (one step colder) at OEM spec gap (0.7.) I had a rough idle before, and now everything is perfect!