Hi chaps.
Could someone tell me what type plugs and gaps size is the best for a 2lt yb cosworth,
It has a 330 chip 3bar map sensor greens and a s111 turbo technics hybrid turbo, T/technics say turbo good for 300/310bhp set at 18psi thats as high as they will warranty it for.
Paul.

 

BCR8ES with 0.6 gap

 

mines running about the same and i have ngk bkr9eix iridium plugs.my old ones were gapped at .75 where as i have gapped my new ones at .65.i havnt used it yet so i dont know if its going to be any better.at .75 it only ever give me a problem once on boost in 3rd,but on the advise of someone else i was told to gap my new ones at .65.

 

Denso IK31's.

 

I'd go with IK31 too, good plug, gap is dependant on coil being used, wider does not mean better, wider gaps came about to ignite weaker eco freindly fuel mixtures.
I have a ACCEL coilpack on my sapph and gapped at 0.5mm, on std 3ms coil time.
The difference with the ACCEL coilpack is very significant especially low down and when cold, about £65 but well worth it.
tabetha

 

I waited for you to post your pro-IK31 answer

 

I can only say I have had no issues with them, they seem pretty resistant to fouling, as I drive like an old grandad sometimes, and they never do anything but behave right.
I had some 071's in there at one time, they did the job ok, but just seems more eager with Ik31, if on coilpack though I can defo recommend a ACCEL coil part number 140018, this is the early type coilpack, about 40% more energy and according to the blurb better spark duration, certainly makes a difference though, as I am looking now for one for my other halfs astra.
tabetha

 

Yep, therefore I'm switching my standard answer to IK31

 

I forgot to mention I have also a group a coil so is the spark plug the same, also im a bit unsure about what the plugs are called do I just ask for pro ik31s or what ever

 

Doesn't make any difference.

Ask for Denso IK31 or NGK BCR8ES