Uryelowducky

iTrader: (3)

So I currently have iridium spark plugs put in by English racing about 50 k miles ago. Recently I started having my knock sensors flash on when I get around 6-8 k rpm especially when the car is under load at max boost 23.5 which cuts my fuel n makes the car go limp. I can recreate the knocks by hitting full boost. It would happen about 60% of the time.

What's the prefered spark plug and gap? I'm on stock turbo at 350 whp.

llDemonll

iTrader: (21)

stock plugs

heel2toe

iTrader: (41)

NGK BPR7EIX gaped at .025 is what I do. Depending on your ignition system and the amount of boost will determine your gap.

On a different note it sounds like your issue is related to the tune though and not the plugs.

APEXR

iTrader: (5)

I'm guessing you didn't have any issues up until now? I'd start by checking the plugs if you haven't. Thought I had a boost leak or fuel problem myself with same thing as you described, turns out it was just time for some new plugs. Ironically I had about 50k on my plugs as well. Off the top of my head I don't remember exactly which ones I replaced them with but will dig around for you later if it'll help.

Uryelowducky

iTrader: (3)

It definitely wasn't the tune. Ran good for a while. Yeah It's probably just time for new plugs.

hang187

iTrader: (7)

Yes new plugs. Mine did the same thing last year.

APEXR

iTrader: (5)

Had a chance to look and also running NGK Iridium BPR7EIX. Good luck and post up what you find.

Uryelowducky

iTrader: (3)

Yeah I ended up purchasing a set of BPR7EIX and a set of BPR8EIX. They are both iridium.

Got each set for about 35 dollars on eBay. I'm gonna play around with both sets to see which one my car likes better. Also trying to figure out how much I should gap it.

SilverShadow03

iTrader: (19)

FYI...Normally you don't gap iridium plugs because they come pre-gapped, although you can check the gap if you are very careful. The iridium electrode is very brittle and not hard to break off.

You run the risk of doing more harm than good by trying to gap them...if you are really concerned with the gap, CAREFULLY check the gaps and go from there.

Seeing how you are lightly modded, you could probably get away with copper NGK plugs a step colder or two than stock. I run NGK BPR7ES gapped at .26 and I'm good to go!

Lucas English

iTrader: (12)

.020 is the gap we run. .025 if you want to mess with plugs ever 1000mi. We gap iridium also but have to use a feeler gauge not a gapper. I normally make a .019 barely rub on iridium so I dont have to worry about messing up the tip.