Proper plug gapping
Thread Starter
Melting Slicks
Joined: Nov 2000
Posts: 2,469
Likes: 6
From: Winchester Ontario
Proper plug gapping
I am currently running NGK TR6's gapped at 0.038. I have the TR6 due to my nitrous application. I also am using MSD 6AL ignition and Taylor Spiro Pro 8 mm plug wires. I read in an archive that someone said to run plug gap at 0.035 for nitrous.
Question is..what benefit would the 0.035 have over the 0.038 plug gap during nitrous and non-nitrous use? 99 % of the time, I am running without the nitrous on, so would having a different gap size affect nitrous and non-nitrous application performance?
Question is..what benefit would the 0.035 have over the 0.038 plug gap during nitrous and non-nitrous use? 99 % of the time, I am running without the nitrous on, so would having a different gap size affect nitrous and non-nitrous application performance?
Le Mans Master
Joined: Jul 2001
Posts: 6,252
Likes: 2
From: Silicon Valley Kalifornia
Re: Proper plug gapping (black_89_vette)
As you increase cylinder pressures (ie nitrous) jumping a spark across a given gap becomes more difficult. Hence a shorter gap for nitrous (or a beefed up ignition system). Optimally, you want to run the largest gap you can for ignition efficiency.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Proper plug gapping (black_89_vette)
My guess is that NOS changes the breakdown potential of the charge compared with a NA application, so the closer gap.
For a NA application you can run wider gap with a HO ignition setup; e.g. I run .045" with my HyperTech coil/cap/rotor & TPIS wires, along with cut-back electrodes.
Since going lean is the big fear with NOS I think you would be ok with either setting; if you decide on .035" it will also be fine for NA operation as that is the stock setting.
For a NA application you can run wider gap with a HO ignition setup; e.g. I run .045" with my HyperTech coil/cap/rotor & TPIS wires, along with cut-back electrodes.
Since going lean is the big fear with NOS I think you would be ok with either setting; if you decide on .035" it will also be fine for NA operation as that is the stock setting.
