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spark plugs for m20 turbo
Posted: Tue May 27, 2008 5:33 pm
by midnight
which plugs should i go for, standard ngk ones or a colder acting plug?
Re: spark plugs for m20 turbo
Posted: Tue May 27, 2008 7:14 pm
by Colonel Sanders
around 3 degrees colder for over 1 BAR kev.
you far on your build yet?
Re: spark plugs for m20 turbo
Posted: Wed May 28, 2008 5:40 pm
by midnight
yeah im getting on ok with the build just waiting on parts as usual, cus on my old one i think i used volvo plugs but cant remember, what ones are u using?
Re: spark plugs for m20 turbo
Posted: Wed May 28, 2008 6:58 pm
by Colonel Sanders
Q: What plugs should I use? what should I gap them to?
A: NGK 3923 BPR8ES plugs. Their 3 degrees colder than stock. i gap them to .025". For 1.0 bar or more boost, even colder plugs are recommended (BPR7ES).
I found some more information about NGK spark plugs, and their related part numbers for heat ranges.
http://www.ngksparkplugs.com/techinf...tnumberkey.pdf
Apparently, the lower the number, the hotter the plug. So that would make a BPR7ES Hotter (not colder) than a BPR8ES. Stock would be BPR5ES, or for the v-power series, ZGR5A. Unfortunately they do not make a ZGR7A or something of the sort.
General thumb of rule, every 75-100 hp added, you take 1 step colder.
copy that from another site, im using BPR7ES
Re: spark plugs for m20 turbo
Posted: Wed May 28, 2008 8:12 pm
by midnight
do u rekon i could pick these up in any local spares shop sean? and are they actualy bmw ones of are they designed for another car, ie what car would they be labelled up for?
Re: spark plugs for m20 turbo
Posted: Wed May 28, 2008 8:41 pm
by Colonel Sanders
just your standard ngk plugs from your local store mate. just ask for m20b25 fitment as in length
Re: spark plugs for m20 turbo
Posted: Thu May 29, 2008 6:23 pm
by midnight
nice one sean, ill bowl down there and sort some out
Re: spark plugs for m20 turbo
Posted: Thu May 29, 2008 6:58 pm
by Colonel Sanders
anytime mate, looks as though your closer to finishing than i am!!

Re: spark plugs for m20 turbo
Posted: Thu May 29, 2008 8:50 pm
by midnight
well hopefully shouldnt be too long now, are you going to ultimate strret car at santa pod? so are u using that head that u bought off me?
Re: spark plugs for m20 turbo
Posted: Thu May 29, 2008 9:28 pm
by Colonel Sanders
yeah if its ready il be comin up in it, and if its run in i will take it up the strip with hopefully around 500hp..
yeah using your head and cam still, i got it oringed and had the cooling channels welded up.
next on the list is a custom inlet manifold...
Re: spark plugs for m20 turbo
Posted: Thu May 29, 2008 9:33 pm
by Turbo-Brown
I'd say if you can only gap them to 0.6mm, your sparking system isn't powerful enough!
I ran fractionally under a 1mm gap from the start. Decided to reduce this one day to whatever the book says it should be which I seem to recall is in the region of 0.6mm.
It was like the car had been castrated! It was just so limp after that!
Had them out and re-gapped them and all was well with the world again

Re: spark plugs for m20 turbo
Posted: Thu May 29, 2008 10:34 pm
by midnight
well ive got the gm coil park on there, and as i can recall i think its quite a good dwell timing and ballast for a good spark, so bit of a hit or miss one possibly, 500hp sean thats sounding pretty fierce, i hope to have a race with u at usc then, well im in the middle of making up a sweedish plenum style inlet manifold for my m20, so if it works out well, it mite be a good ideal for yours too
Re: spark plugs for m20 turbo
Posted: Thu May 29, 2008 10:51 pm
by Colonel Sanders
yeah, i doubt il get it this year though, its cost me enough already!!lol i just wanna drive it now...
Re: spark plugs for m20 turbo
Posted: Thu May 29, 2008 11:12 pm
by midnight
true i know the feeling