Plugs (95770 v. 97506), gaps, and the N54

[ShocknAwe]

So I'm reading through this and trying to decipher what the optimum starting point for a ~500whp car would be in terms of plug and gap when combined with PR etc coils would be. I'm gathering that we can open it up from .022, but some are seeing misfires at .03, and PR states no benefit to opening the gap from .022

Is there a consensus yet that I'm missing?

 

[fmorelli]

I don't believe there is a consensus. @doublespaces gets around ... he might say NGK 97506? My tuner wants me at 0.022" even with the R8 coils. I'm probably close to 450-500 on E80, maybe shy ... I still have not nailed down my operating points given BL harness issues. That said:

• Reported gaps vary from 0.018" to 0.030"
• 0.022" seems a common recommendation.
• NGK 97506 is a darling recommendation but I'd like to know that the long reach on the plug does not get washed by the injector. No one has verified.

It would be good to hear the tuners weigh in, if willing. They have seen and tuned a bunch of these configurations: @Twisted Tuning @BQTuning @V8bait @WedgePerformance et al.

Filippo

 

[NoQuarter]

I'm probably close to 450-500 on E80, maybe shy

That estimate seems pretty high (or I am too low on my own estimate). You are on stock turbos still correct?
I would have guessed I am at 400-420 but have not been on a dyno.

 

[veer90]

FWIW, I made 692 whp / 570 wtq on modified R8 coils and NGK 97506s @ 0.018" gap. Lower gap than I would have ran, but it misfired on the dyno at 0.028" gap and we wanted to regap once and be done so we went lower to be safe. Haven't bothered to widen the gap, but I will at some point.

I've pulled my plugs multiple times and there's no sign of fuel hitting the tip or ground strap, nor any sign of knocking. Overall they look excellent after close to 10k miles of abuse.

 

[RSL]

Not sure a power target is the best benchmark. 450-500whp can be made in many ways and in infinite curves. If you're on stock turbos with 10-15 gallons of E85 and a tune strong enough to get there, it isn't going to be the same as 450-500whp on hybrids or singles and 93 or E20-E30. A lot of E85 or the tunes alone could make it a different area of the ballpark all else being equal. Just not sure anyone will ever know what they can run unless they actually try it, but curious to hear what tuners are seeing...

 

[Twisted Tuning]

Educated opinion. 95770 plugs are fine in these cars to about 750-800whp. Lower than that there is no need for two step colder plugs. Especially when 98% of people in that power range are running E85.

There are 1000whp GTRs running STOCK Heat plugs (Heat Range 8). The 95770 are heat range 7. no reason to go colder at 99% of this communities power level. ESPECIALLY with DI.

Spark plug gap i will never recommend smaller than .022 gap. Which is still small compared to other platforms i support. Only time i have mentioned anything smaller, is during a SPECIFIC troubleshooting time, or testing something.

When it comes to gap. You want the largest gap possible for a setup to where jumping the gap is not prohibited.

 

[fmorelli]

That estimate seems pretty high (or I am too low on my own estimate). You are on stock turbos still correct?
I would have guessed I am at 400-420 but have not been on a dyno.

Hey I can dream, can't I?!?!?!

Filippo

 

[Rob09msport]

Hey I can dream, can't I?!?!?!

Filippo

I would think over 450 def pos with the better lpf setup of z and custom tune i would think sonething wrong of you werent in the 450 range 400 to 430 would be 93 imo

 

[V8bait]

For OEM coils I recommend .022" until it's an issue (hybrids pushed hard), then .018" or even 0.017" in some cars. For aftermarket coils I generally recommend .022" to .026", although I've not seen any gains over .022" so I think larger is mostly unnecessary. If you're heavy on the PI then a little larger may be nice. JMO, gap is a small part of the build and even a .040" gap isn't going to get you to 1,000hp on your RB turbos.

 

[pdxbimmertech]

ZMR or ZR? Been using the OE S55 plugs since 2015 and are the best plugs I've ever tried, which I've been trying to elaborate for 3 pages

Edit: I see on the Bosch P/N now, those are OE N55 plugs. I'm referring to the S55 OE plugs.

Yes, for all reasons.

1mm gap = .039", the common .018-22" gaps are 0.46-0.56mm or less than half of the minimum shown on this chart. It impacts flame worse at leaner lambda.

View attachment 13702

The Bosch plugs that the parts supplier listed for the N20 were the number I posted, read directly off the box and the side of the plug. ZR5TPP330. Shows a gap of .032" with a platinum, single electrode. Not sure if their listing is correct or not as I have ran into incorrect parts being listed in their system. I did put that number into google and search it and some other online parts places listed them as well for the N20.

 

[Rob09msport]

So your saying the n55 and s55 are same or different i was under impression they are the same just one has m on it

 

[JimboFresh206]

i just gaped a set of s55 plugs and the actual tip has a slightly different shaped electrode. aside from there being a "M" on them lol. kinda hard to see but the OEM n55 plugs have a much more "chode" like electrode.

 

[Rob09msport]

Points for awesome use of chode

 

[RSL]

So your saying the n55 and s55 are same or different i was under impression they are the same just one has m on it

They were close, but different per RealOEM as of last week. The last 3 characters are mostly wafer size/material or other special construction and gap, but the original numbers have changed and might have again and RealOEM hasn't updated. Hell, they might've been the same damn plugs all along with the OE S55 plug just having the ///M on it like you said. Short of that, the P/Ns are essentially the same. If they are the same plug, great plug in my experience with them, but odd the M version is like 50% cheaper than the non-M right now

RealOEM info:

N55	ZR5TPP33S	12120037582	9/2009 -
	RB ZR5TPP332-S	12120037575	8/2009 - 3/2009

[TBODY] [/TBODY]

S55	RB ZMR5TPP330	12120039634	7/2013 -
	RB ZMR5TPP339	12120038832	9/2011 - 6/2013

[TBODY] [/TBODY]

 

[AZN54]

Thank you for the great information and discussion here. I'm looking forward to the updates as you continue testing.

I've been using 95770 plugs at .022 since FBO (stock turbos), e54, and Bosch coils without misfires or timing corrections (made 480whp/550tq). Since going ST 1k miles ago, I have not touched the coils or plugs yet, but now have corrections up-top; no misfires. I'm only running e30 at 21-22psi so may be fuel related. I ordered a set of 95706 to give those a shot, but have little expectations. In case anyone wants to order 95706 (SILZKBR8D8S), Amazon has a pretty good deal going: https://www.amazon.com/gp/product/B01MQH2QAN/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

Being as Prime isn't available from this seller, I wont have them installed for a week or more. I'll report back on any changes to misfires or corrections.

 

[Rob09msport]

I am still waiting for my s55 plugs from ecs tuning so don't feel bad. I should have gone Amazon but didn't I'd prob have them already.

 

[Rob09msport]

I thought my car was running good but v8 just told me if we pull anymore timing I'll be running an acn 91 map so i bought 5 gal of ms109 and mixed 1 gal in and am going to switch to shell from cumberland farms which i just found out is gulf. If turns out it is octane i may just start driving back to ny and filling a drum just this time I'll do e20 so i don't have to go every week like i did on e60 or it may be flex fuel or meth time.

 

[Rob09msport]

I just installed my s55 plugs I can't believe how dirty some of my threads were and how bad the seats were. Bmw is the last one that touched they prob don't clean the seat but I also don't believe the crush washers seal a second time cause I put ms109 in and still got corrections with my 95770s that have been in and out a few times

 

[LMB335is]

ZMR or ZR? Been using the OE S55 plugs since 2015 and are the best plugs I've ever tried, which I've been trying to elaborate for 3 pages

Are you stock turbo running E? Those S55 plugs are ridiculously cheap compared to the NGK 95770's I use now with the PR coils @ .025. I may stock up on them at these prices.

 

[RSL]

Are you stock turbo running E? Those S55 plugs are ridiculously cheap compared to the NGK 95770's I use now with the PR coils @ .025. I may stock up on them at these prices.

Hybrids on pump, but yes, damn cheap. I'm going to order a few more sets myself. Not sure what the deal is with the pricing, but going to take advantage of it while it lasts.