Plugs/Gap - Modified LT4s

JSH · 09-06-2022, 11:30 AM

When I changed to this blower, I also changed to NGK 6510, w/.028 gap.

I'm wondering what others here have done for new plugs/gap?

LiqTenExp · 09-06-2022, 11:43 AM

I'm running Brisk RR14S @ 0.029 with a TVS2300 @ 14-15 psi

*radz28* · 09-06-2022, 02:57 PM

Not as modified as a lot of you, but running, as suggested by JRE, about .040" and around 15-16-psi. Running 1-step colder NGK Iridium for now. Might go down one more step to see how he likes it.

swisstyphoon · 09-06-2022, 03:25 PM

I also use the NGK 6510, gapped to 0.035 at 17psi boost.

IneedAZ · 09-06-2022, 08:39 PM

I too am running the Brisk at 14-15 psi boost

LiqTenExp · 09-06-2022, 09:15 PM

Stock LT4 is 0.030, not sure why you'd go that much larger, in fact some brands wouldn't want you to open them up that far.

SATINSTEEL1LE · 09-06-2022, 09:21 PM

6510 NGK LTR7IX IRIDIUM

JSH · 09-06-2022, 10:24 PM

Quote:

Originally Posted by LiqTenExp

Stock LT4 is 0.030, not sure why you'd go that much larger, in fact some brands wouldn't want you to open them up that far.

I agree and I wanted to see what others here are doing, I figured NGK would be popular and am not surprised about the range of gaps posted so far 0.028 - 0.040. Such larger gaps scare me.

ZLRob · 09-06-2022, 11:26 PM

Quote:

Originally Posted by LiqTenExp

Stock LT4 is 0.030, not sure why you'd go that much larger, in fact some brands wouldn't want you to open them up that far.

Agreed.

.028- .031 is a great nominal range to run plugs on boosted applications due to the excess pressure that boost induces into cylinders. Any more than that and high boost levels equals spark blowout which would be bad news.

swisstyphoon · 09-07-2022, 05:43 AM

Quote:

Originally Posted by LiqTenExp

Stock LT4 is 0.030, not sure why you'd go that much larger, in fact some brands wouldn't want you to open them up that far.

No, stock is 0.037 to 0.043

ZL14ever · 09-07-2022, 05:54 AM

Denso ITV27 at their stock gap (~0.030). Good enough for 22 PSI from Mag 2650

swisstyphoon · 09-07-2022, 06:00 AM

I'm with Ted on this topic.
Good explanation in this video https://youtu.be/G_DiTh8gQ6w

Just like they taught us at mechanic school, your spark will be stronger with a larger gap. Because the Voltage is raising to jump the gap. But yes there is a point where your ignition system is maxed out, and the spark might not be able to jump the gap anymore with raised cylinder pressure. This is when you have to compensate the pressure by closing the gap. Ted said it well, you always benefit from running the max. POSSIBLE gap.

For example.
When I imported my ZL1 to Switzerland, after it just came from a performance shop in Florida it did not run well. Cutting out and stumbling. Lots of missfires, especially with every cold start.
Turned out they gapped the new plugs to 0.027.
Then I installed new plugs, gapped to 0.037 and it ran perfect after.

Now after more mods, and higher boost / cylinder pressure, I closed the gap to 0.035. This is also what alot of big name tuners recommended for my setup.

Not sure what boost you are planning to run, but if it is around 20psi I would say you are ok with that 0.029 gap.

LiqTenExp · 09-07-2022, 06:11 AM

My memory failed me on that one, the spec you have is correct for plug gap.

I do remember being on the dyno and having to gap them down to ~0.030" from ~0.040" or so once hitting around 15 psi on TVS2300. That's what it took to get the most power, timing, and no misfires to 7k rpm on my car. My car is running 93 with 50/50 water/meth (mostly for cooling and a little octane). It might be possible to go a little wider but not sure I'd find the benefit easily. I did find the Brisk plugs were much less prone to misfires, might be an opportunity to go wider and see.

I'm not sure what fueling everyone is using and if running E blends changes the game here with gap.

EDFHOBBIES · 09-07-2022, 07:35 AM

NGK 6510 gap to .022 for me

09-06-2022, 11:30 AM	#1
JSH Drives: '20 ZLE Join Date: Jun 2020 Location: Mile High Posts: 3,560	Plugs/Gap - Modified LT4s When I changed to this blower, I also changed to NGK 6510, w/.028 gap. I'm wondering what others here have done for new plugs/gap? __________________ '20 ZL1 1LE A10, OEM short block, LME heads/valve train, E2650. 100+ octanes, no eth, no meth, no N2O. 2/23 - 1031/1004 wheel. 4/23 - 1.41/9.61/145 at DA 7000 ft. (only made five passes). 2/24 - LME 390, E2650, FBO, 100 oct.; 1116hp/ 1063tq; 109 oct. dyno next.

09-06-2022, 11:43 AM	#2
LiqTenExp Drives: 2017 ZL1 Join Date: Jan 2017 Location: NJ Posts: 905	I'm running Brisk RR14S @ 0.029 with a TVS2300 @ 14-15 psi __________________ 2017 Camaro ZL1 Coupe M6 (847whp Dynojet on 93)

09-06-2022, 02:57 PM	#3
radz28 Petro-sexual Drives: Ultra-Grin Join Date: Oct 2006 Location: Crazy Coast Posts: 15,201 View My Garage	Not as modified as a lot of you, but running, as suggested by JRE, about .040" and around 15-16-psi. Running 1-step colder NGK Iridium for now. Might go down one more step to see how he likes it. __________________ '20 ZL1 Black "Fury" A10, PDR, Exposed CF Extractor Magnuson Magnum DI TVS2650R // RFBG // Soler 103 // TooHighPSI Port Injection // THPSI Billet Lid // FF // Katech Drop-In // PLM Heat Exchanger // ZLE Cradle bushings // BMR Chassis-Suspension Stuff // aFe Bars // Diode Dynamics LEDs // ACS Composites Guards // CF Dash // Aeroforce // tint // other stuffs

09-06-2022, 03:25 PM	#4
swisstyphoon Former GM Technician Drives: 2018 ZL1 A10, 06 Silverado Duramax Join Date: Sep 2009 Location: Switzerland Posts: 341	I also use the NGK 6510, gapped to 0.035 at 17psi boost. __________________ 2018 Camaro ZL1 A10 Rotofab Big Gulp, Nick Williams 103, Magnuson 2650, 9.17" (14%) lower, 90mm upper, Vengeance Racing Heads (LME) Cam Package (Cammotion Stage 1), Johnson Lifters, JMS Voltage Booster, Lingenfelter high flow check valve, BBK shorty headers, Custom 2.75" down pipes, Gesi Gen2 high flow cats, MM catch can 791whp, 772ft-lbs SAE Just added 30% XDI Injectors, LPE big bore hpfp, Flex fuel. Elite tuning, results coming soon. 2006 Silverado Duramax Diesel MPI Compound Turbo 40% over Injectors Efi Live DSP5 Tuning Follow me on Instagram: Swisstyphoon1980 Last edited by swisstyphoon; 09-07-2022 at 05:40 AM.

09-06-2022, 08:39 PM	#5
IneedAZ Drives: 2017 ZL1 A10 & 2021 BMW M340i x Dr Join Date: Mar 2009 Location: Tampa Posts: 5,110 View My Garage	I too am running the Brisk at 14-15 psi boost __________________ Sold 2012 2LT RS 12.3@112 old setup Sold 1967 Camaro Pro Street. Ran 10's mild BB on NOS. 2017 HyperBlue ZL1 A10 Born 3/17/17Delivered 4/08/17 2020 Build: Mag2650, BTR Stage2, NW103, BG, 14% lower, 90mm upper, ARH 2" Long system w/no cats, SW Legend mufflers. 807hp/762tq on 93 gas and 848hp/792tq on e47 Sold 2018 (Go Mango) Dodge Charger Daytona 392 Daily Driver Daily Driver 2021 BMW M340i Xdrive

09-06-2022, 09:15 PM	#6
LiqTenExp Drives: 2017 ZL1 Join Date: Jan 2017 Location: NJ Posts: 905	Stock LT4 is 0.030, not sure why you'd go that much larger, in fact some brands wouldn't want you to open them up that far. __________________ 2017 Camaro ZL1 Coupe M6 (847whp Dynojet on 93)

09-06-2022, 09:21 PM	#7
SATINSTEEL1LE Account Suspended Drives: 21 ZL1 Join Date: Feb 2022 Location: South East Posts: 662	6510 NGK LTR7IX IRIDIUM

09-07-2022, 05:54 AM	#11
ZL14ever Drives: 2018 Camaro ZL1 A10 Join Date: Feb 2022 Location: Dubai, UAE Posts: 63	Denso ITV27 at their stock gap (~0.030). Good enough for 22 PSI from Mag 2650

09-07-2022, 06:00 AM	#12
swisstyphoon Former GM Technician Drives: 2018 ZL1 A10, 06 Silverado Duramax Join Date: Sep 2009 Location: Switzerland Posts: 341	I'm with Ted on this topic. Good explanation in this video https://youtu.be/G_DiTh8gQ6w Just like they taught us at mechanic school, your spark will be stronger with a larger gap. Because the Voltage is raising to jump the gap. But yes there is a point where your ignition system is maxed out, and the spark might not be able to jump the gap anymore with raised cylinder pressure. This is when you have to compensate the pressure by closing the gap. Ted said it well, you always benefit from running the max. POSSIBLE gap. For example. When I imported my ZL1 to Switzerland, after it just came from a performance shop in Florida it did not run well. Cutting out and stumbling. Lots of missfires, especially with every cold start. Turned out they gapped the new plugs to 0.027. Then I installed new plugs, gapped to 0.037 and it ran perfect after. Now after more mods, and higher boost / cylinder pressure, I closed the gap to 0.035. This is also what alot of big name tuners recommended for my setup. Not sure what boost you are planning to run, but if it is around 20psi I would say you are ok with that 0.029 gap. __________________ 2018 Camaro ZL1 A10 Rotofab Big Gulp, Nick Williams 103, Magnuson 2650, 9.17" (14%) lower, 90mm upper, Vengeance Racing Heads (LME) Cam Package (Cammotion Stage 1), Johnson Lifters, JMS Voltage Booster, Lingenfelter high flow check valve, BBK shorty headers, Custom 2.75" down pipes, Gesi Gen2 high flow cats, MM catch can 791whp, 772ft-lbs SAE Just added 30% XDI Injectors, LPE big bore hpfp, Flex fuel. Elite tuning, results coming soon. 2006 Silverado Duramax Diesel MPI Compound Turbo 40% over Injectors Efi Live DSP5 Tuning Follow me on Instagram: Swisstyphoon1980

09-07-2022, 06:11 AM	#13
LiqTenExp Drives: 2017 ZL1 Join Date: Jan 2017 Location: NJ Posts: 905	My memory failed me on that one, the spec you have is correct for plug gap. I do remember being on the dyno and having to gap them down to ~0.030" from ~0.040" or so once hitting around 15 psi on TVS2300. That's what it took to get the most power, timing, and no misfires to 7k rpm on my car. My car is running 93 with 50/50 water/meth (mostly for cooling and a little octane). It might be possible to go a little wider but not sure I'd find the benefit easily. I did find the Brisk plugs were much less prone to misfires, might be an opportunity to go wider and see. I'm not sure what fueling everyone is using and if running E blends changes the game here with gap. __________________ 2017 Camaro ZL1 Coupe M6 (847whp Dynojet on 93)

09-07-2022, 07:35 AM	#14
EDFHOBBIES Dyno Show Queen LOL Drives: 16 SS & 17 ZL1 Both Yellow Join Date: Jan 2014 Location: Houston Posts: 4,345 View My Garage	NGK 6510 gap to .022 for me __________________ Kong Ported 2650, Crawford Racing Port Injection, Weapon X 112mm Adapter, NW112mm TB, Livernois Ported LT4 Heads, Lingenfelter GT32 stealth cam, Haltech Elite, and Carbon by Trufiber

User Name		Remember Me?
Password