[nicky dj]

Finally pulled the trigger on some NGK 2-step colder plugs from Bosch OEM. Not really asking what should I should gap them to, but why?

The consensus from most posts are to gap them at .22. Burger Tuning recommends .20. Vehicular gapped his at .19 as the median. I've seen a few tuners on here say go as low as .18. The range seems to be .18-.26. What are you running and why? Is it dependent on your setup, or logs?

I'm FBO running an MHD E30 map btw.

[hellokitty]

.018 if planning to run E40-E60 protune on stock coils.

Mine is set at .028 but I have PR coils and didn’t want to have premature spark plug wear.

[Rule1977]

I'm FBO JB4/MHD BEF on e30. I'm gapped at .22 on NGK 97506 with no issues whatsoever. Terry at BMS recommended .22 on stock turbos.

[nicky dj]

Thanks guys, appreciate the info per what type of setup you're running. Haha I might go with the average between the two of you .20 (and what's listed on BT's site) as I'm planning to run a e50 protune soon.

[JM98]

OEM Bosch plugs with OEM coils running E40 FBO for 15k Miles without issue. Didn't find a need to change up plugs/coils on stock turbos.

[nicky dj]

Originally Posted by JM98

OEM Bosch plugs with OEM coils running E40 FBO for 15k Miles without issue. Didn't find a need to change up plugs/coils on stock turbos.

I was running Bosch OEM FBO for 13k, 2k on e30 no problems until recently I got a misfire and not smooth idle, hence the switch up. Not sure if that's due to that wear of the plugs or not but I thought I'd take the plunge considering going beyond FBO e30.

[type-dRew]

I run stage 2+ maps and ethanol blend maps up to e60. Boost up to 21.5 peak on some maps.

I have run oem n54 bosch plugs without issue(triple strap). Currently running OEM N55 plugs(single strap, step colder than n54 oem) at stock gap with no issue. Gap is about .028 out of the box.

[N54_ABQ]

I run .020" on the NGK 97506's. New Eldor coils, stock turbos @20psi, E60 and the usual bolt-ons.

I started with .022" and had WOT misfires. Moved to .018", that fixed the WOT misfire but then had cold start misfires. Settled on .020" and have had zero problems from cold start to WOT.

I changed to the NGK's after melting an OE Bosch plug!

[type-dRew]

Originally Posted by N54_ABQ

I run .020" on the NGK 97506's. New Eldor coils, stock turbos @20psi, E60 and the usual bolt-ons.

I started with .022" and had WOT misfires. Moved to .018", that fixed the WOT misfire but then had cold start misfires. Settled on .020" and have had zero problems from cold start to WOT.

I changed to the NGK's after melting an OE Bosch plug!

How did you melt an oe plug?

I literally run the most aggressive map available on mhd, without all the mods it requires, and my plugs look great, good color without any strap wear after 15k miles. Just pulled and cleaned them a few times, put them back in without worry before going to n55 plugs to try.

[N54_ABQ]

Originally Posted by type-dRew

How did you melt an oe plug?

I literally run the most aggressive map available on mhd, without all the mods it requires, and my plugs look great, good color without any strap wear after 15k miles. Just pulled and cleaned them a few times, put them back in without worry before going to n55 plugs to try.

I still don't know exactly why. Only cyl.2 was affected.
Injector checked out fine. Compression was ~175psi, same as all other cylinders and fuel pressures have always been perfect.
I had used OE plugs without issue until then.

[mweisdorfer]

MHD stage 2+

FBO plus inlets & outlets as well as AFE momentum CAI box

I run NKG one step colder plugs at .022 & Eldor Coils.

Car runs extremely smooth.

[IllSic_Design]

N54
FBO Stage 2+ Flex Fuel - usually E50. Stage 1 turbos, inlets, outlets, dci, dp, etc.

NGK 97550 at .022. and Eldor coils.

[johnscales]

Old post but I have something interesting to add.
I've just changed out my one step colder plugs with another set and have been running NGK's for the past 5 years. Please bare with me while I explain stuff.
After many years of running @.022 and self tuning and averaging between 17 - 21 mpg mixed driving I happened upon a map over the past couple of months that has been giving me between 25 and 28 mpg whilst maintaining 560whp (virtual dyno, same stretch of road for the past 7 years).
Upon changing out my old NGK's a couple of days ago (about 5k on them) and gapping the new ones to the usual .022 my mpg has fallen back to 18 -19 mpg range.
Hmmm... the new map was good for 25-28mpg previously so what gives?
I've just checked the gapping on my older plugs and found that four of the six plugs are .023 or a very tight .023. The other 2 are a 'loose' .022 but not quite .023 (sort of .0225) .
I am about to pull and regap all of the new 6 plugs to .023.
Could .001 inch really make a difference of 7 to 10 mpg? I'm doubtful but am definitely up for the investigation. About to find out for real. No theoreticals. Will check and update in this post in the next couple of days as it will be amazing if this small change could have such a big difference in engine efficiency.
Btw the older SP's are all good/clean colourwise. Cylinder 6 was running hot but a guy across the road from me mentioned that 'cylinder 1 or 6 usually runs hotter than the rest' before I even pulled it.
He knows nothing about N54's and seemed to mention it as being 'a thing' with most engines so I'm ok with that.
For info my mods are FBO (5" intercooler) with RBTwos turbos + meth.

[johnscales]

Day 1 : 50+ miles mixed driving (Couple of WOT pulls) 21.7mpg.
That's +3-4 mpg already. and there's definitely more grunt out of boost. In boost feels the same... crazy. 568/547 whp/lbft. Had a missfire @ 6000rpm and thought it might be the gap but logs showed -20 stft on bank 1 so I pulled fuel and ran again. No misfire with a -3 timing pull on bank 4 which is nothing to worry about.
Can't believe that much difference can be had on fuel consumption with a 1/1000th inch gap change.
Will run the tank and see where i'm at after that.
If anyone comes across this in the next couple of days do you think it's worth trying .024? WHat symptom would tell me it's no longer working, misfires?

[TyroneShoelaces]

Originally Posted by johnscales

Day 1 : 50+ miles mixed driving (Couple of WOT pulls) 21.7mpg.
That's +3-4 mpg already. and there's definitely more grunt out of boost. In boost feels the same... crazy. 568/547 whp/lbft. Had a missfire @ 6000rpm and thought it might be the gap but logs showed -20 stft on bank 1 so I pulled fuel and ran again. No misfire with a -3 timing pull on bank 4 which is nothing to worry about.
Can't believe that much difference can be had on fuel consumption with a 1/1000th inch gap change.
Will run the tank and see where i'm at after that.
If anyone comes across this in the next couple of days do you think it's worth trying .024? WHat symptom would tell me it's no longer working, misfires?

Coming from a machinist/engineer with 20 years in micro machining I highly doubt you're gapping a plug within half a thou. Really you shouldn't be dragging a feeler gage over the electrode to begin with and opening and closing the gap within that range is unlikely imho.
And .0005 isn't going to matter to the car I think. Temp, fuel, custom tune, and a hundred other variables are going to affect the car more. But that's my opinion.

[Tambohamilton]

Originally Posted by TyroneShoelaces

Coming from a machinist/engineer with 20 years in micro machining I highly doubt you're gapping a plug within half a thou. Really you shouldn't be dragging a feeler gage over the electrode to begin with and opening and closing the gap within that range is unlikely imho.
And .0005 isn't going to matter to the car I think. Temp, fuel, custom tune, and a hundred other variables are going to affect the car more. But that's my opinion.

+1

Way more likely to be caused by something else; fuel quality, ambient temps, or any combination of 100 other variables that would have more effect than a tiny bit of plug gap.

[iqraceworks]

I've been running .020" gap on my plugs for the last couple of years on my E40 25psi tune...no issues at all. Just installed a brand new set of coils and plugs over the weekend (thanks FCP!!)....gapped them at .020" just like the other set.

[iqraceworks]

Originally Posted by johnscales

Old post but I have something interesting to add.
I've just changed out my one step colder plugs with another set and have been running NGK's for the past 5 years. Please bare with me while I explain stuff.
After many years of running @.022 and self tuning and averaging between 17 - 21 mpg mixed driving I happened upon a map over the past couple of months that has been giving me between 25 and 28 mpg whilst maintaining 560whp (virtual dyno, same stretch of road for the past 7 years).
Upon changing out my old NGK's a couple of days ago (about 5k on them) and gapping the new ones to the usual .022 my mpg has fallen back to 18 -19 mpg range.
Hmmm... the new map was good for 25-28mpg previously so what gives?
I've just checked the gapping on my older plugs and found that four of the six plugs are .023 or a very tight .023. The other 2 are a 'loose' .022 but not quite .023 (sort of .0225) .
I am about to pull and regap all of the new 6 plugs to .023.
Could .001 inch really make a difference of 7 to 10 mpg? I'm doubtful but am definitely up for the investigation. About to find out for real. No theoreticals. Will check and update in this post in the next couple of days as it will be amazing if this small change could have such a big difference in engine efficiency.
Btw the older SP's are all good/clean colourwise. Cylinder 6 was running hot but a guy across the road from me mentioned that 'cylinder 1 or 6 usually runs hotter than the rest' before I even pulled it.
He knows nothing about N54's and seemed to mention it as being 'a thing' with most engines so I'm ok with that.
For info my mods are FBO (5" intercooler) with RBTwos turbos + meth.

No....something else is going on. You would never notice .001" change in gap.......lots of other factors that would affect things long before that.

[iqraceworks]

Originally Posted by Tambohamilton

+1

Way more likely to be caused by something else; fuel quality, ambient temps, or any combination of 100 other variables that would have more effect than a tiny bit of plug gap.

Yep!

[B58]

I ran .020 with 700HP and .022 and both were fine with the Dinan replacement coil plugs. I preferred .022 as it seemed to idle a bit more smoother.

[johnscales]

Firstly, I'm glad to see people are still on here and thanks to all of you tuned in.
Have filled up my tank and average mpg was 24mpg at the point of filling.
I wouldn't disagree with anyone whom has posted at all but the only thing I could say in response is this.
Taking the general consensus of replys all have mentioned, there being any number of things that could impact my findings, this could well be true. However, none of those things seemed to impact a consistent 17 - 21 mpg for the past 2 years other than solely my custom tuning efforts. I had a horrid 14 -15 mpg for a short amount of time with one tune but soon changed the tune. Otherwise tem changes between Summer and Winter should have influenced my mpg.
Nothing otherwise has changed since my previous spark plugs were in. Same journeys same petrol station (I always use the same one. Always.). Same average amount of pulls per tank of fuel and the same map which gave me 25 - 28 mpg on the old plugs. While not 'Lab tested' it is 'real world'.
Mpg has been consistantly between 17 and 21 for the past few years (trust me I have been anal with noticing this).
Also you have to remember that every car is different and that most of us got the .022 figure from someone else whom was happy with the results it gives along with which ngk plugs to use. Namely, you get good power without misfires.
I'd wager that those same guys whom found this to be a good gap for our motors were not looking specifically at fuel consumpsion either. Rather power levels without misfires.

I'm not looking to start an argument with anyone, just calling it as I experience it. Thanks for all inputs they are welcome and give good pause for thought.

ps
Just found this thread very useful :
https://*********************/thread...54.3718/page-2

Will be adjusting to .024 and going again per #38 thru #40.

Cheers guys.

Seems I can't post other forum names. It's an SS site thread.

[whyzee125]

Originally Posted by johnscales

Firstly, I'm glad to see people are still on here and thanks to all of you tuned in.
Have filled up my tank and average mpg was 24mpg at the point of filling.
I wouldn't disagree with anyone whom has posted at all but the only thing I could say in response is this.
Taking the general consensus of replys all have mentioned, there being any number of things that could impact my findings, this could well be true. However, none of those things seemed to impact a consistent 17 - 21 mpg for the past 2 years other than solely my custom tuning efforts. I had a horrid 14 -15 mpg for a short amount of time with one tune but soon changed the tune. Otherwise tem changes between Summer and Winter should have influenced my mpg.
Nothing otherwise has changed since my previous spark plugs were in. Same journeys same petrol station (I always use the same one. Always.). Same average amount of pulls per tank of fuel and the same map which gave me 25 - 28 mpg on the old plugs. While not 'Lab tested' it is 'real world'.
Mpg has been consistantly between 17 and 21 for the past few years (trust me I have been anal with noticing this).
Also you have to remember that every car is different and that most of us got the .022 figure from someone else whom was happy with the results it gives along with which ngk plugs to use. Namely, you get good power without misfires.
I'd wager that those same guys whom found this to be a good gap for our motors were not looking specifically at fuel consumpsion either. Rather power levels without misfires.

I'm not looking to start an argument with anyone, just calling it as I experience it. Thanks for all inputs they are welcome and give good pause for thought.

ps
Just found this thread very useful :
https://*********************/thread...54.3718/page-2

Will be adjusting to .024 and going again per #38 thru #40.

Cheers guys.

Seems I can't post other forum names. It's an SS site thread.

This is very interesting and I think you may be on to something. My previous N54 always got OEM Bosch plugs and ALWAYS got 23.7 mpg on the Dinan stage 2 tune, for years.

My current one is normally on full e85 and I run .018 gap on NGK 97506 I'm on stock Eldors. Runs and idles great.

Recently had a custom 93 oct Wedge tune made that's very conservative (similar to Dinan) so I switched to 97968 and gapped them to .022 and I can't seem to crack 21mpg. I'm gonna try widening the gap or going to Bosch plugs and see if that changes!