few questions about spark plug gaps
Thread Starter
Joined: Aug 2005
Posts: 2,803
Likes: 1
From: Seminole County, Florida
few questions about spark plug gaps i understand that a smaller gap (.040 area) are necessary for nitrous setups of a certain size
why is this so, what effect does the spark plug gap have on the whole process? what happens if you have a .050 gap, how does that mess up?
why is this so, what effect does the spark plug gap have on the whole process? what happens if you have a .050 gap, how does that mess up?
Thread Starter
Joined: Aug 2005
Posts: 2,803
Likes: 1
From: Seminole County, Florida
Originally Posted by Screamin_Z
Nitrous caues a bigger explosion than N/A so u need a smaller gap to decrease blowing out the spark. the bigger the shot the smaller that gap.
ohh so high compression will actually blow out the little electricity arc? thats crazy, so what happens? power loss or dammage?
what would happened if you put a small gap on a stock engine (something extreme like .030)
on a N/A if u have a small gap it's not going to ignite all the fuel in the cc. I have TR6's w/ a .40 and I haven't noticed a difference at the track w/o nitrous on. I wouldn't go any smaller if u plan on doing the same. nitrous doesn't cause a higher compression, just a bigger bang. forced air causes a higher compression.
If anyone else catches something I've said it wrong please correct me, I don't know everything.
If anyone else catches something I've said it wrong please correct me, I don't know everything.
Thread Starter
Joined: Aug 2005
Posts: 2,803
Likes: 1
From: Seminole County, Florida
Originally Posted by Screamin_Z
on a N/A if u have a small gap it's not going to ignite all the fuel in the cc. I have TR6's w/ a .40 and I haven't noticed a difference at the track w/o nitrous on. I wouldn't go any smaller if u plan on doing the same. nitrous doesn't cause a higher compression, just a bigger bang. forced air causes a higher compression.
If anyone else catches something I've said it wrong please correct me, I don't know everything.
If anyone else catches something I've said it wrong please correct me, I don't know everything.
Trending Topics
AT my work we have a Champion spark plug tester for aircraft plugs. It has an integral cleaner, power source and air pressure source. Its a neat little bench tool.
You screw in the plug into a sealed box that has a small glass window. Plug the coil wire onto the plug and push the button. You will see a bright blue arc in the window as the spark jumps the gap. But with this box you can increase air pressure inside the little window up to 140 psi. The difference between ambient pressure and 140 psi on the bright blue arc is incredible. It becomes nothing more than a yellow kernal. And if the gap is too large it doesnt arc at all. The turbulence along with the increased density will blow the spark out. Shortening the air gap decreases resistance and strenghtens the "connection" to ensure the spark will transfer.
Now imaging adding the density and coldness of a nitrous charge in that mix....you need a tight gap and a strong spark to get that mixture ignited.
But in general you want the largets gap that will do the job to ignite the pressure and mixture you have properly. Going smaller on the gap only ensures there is less chance for it to be blown out. It will not improve performance unless it was actually being blown out.
You screw in the plug into a sealed box that has a small glass window. Plug the coil wire onto the plug and push the button. You will see a bright blue arc in the window as the spark jumps the gap. But with this box you can increase air pressure inside the little window up to 140 psi. The difference between ambient pressure and 140 psi on the bright blue arc is incredible. It becomes nothing more than a yellow kernal. And if the gap is too large it doesnt arc at all. The turbulence along with the increased density will blow the spark out. Shortening the air gap decreases resistance and strenghtens the "connection" to ensure the spark will transfer.
Now imaging adding the density and coldness of a nitrous charge in that mix....you need a tight gap and a strong spark to get that mixture ignited.
But in general you want the largets gap that will do the job to ignite the pressure and mixture you have properly. Going smaller on the gap only ensures there is less chance for it to be blown out. It will not improve performance unless it was actually being blown out.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
You will probably give up about 5-10 HP N/A with (for example) TR6s gapped at .038, which is what I run. The smaller gap decreases the resistance (from the atmosphere) that the spark has to "jump".
Originally Posted by Screamin_Z
but he'll gain so much more with a 150 shot 
Thats right...nothing is ever free.
And I havent seen any real significant loss from TR55 to TR6 at .038 gap. At most on a typical 400 rwhp NA combo maybe 2-3 hp.
Originally Posted by 383LQ4SS
Thats right...nothing is ever free.
And I havent seen any real significant loss from TR55 to TR6 at .038 gap. At most on a typical 400 rwhp NA combo maybe 2-3 hp.
And I havent seen any real significant loss from TR55 to TR6 at .038 gap. At most on a typical 400 rwhp NA combo maybe 2-3 hp.
Ill usually see 10+ rwhp loss on a full nitrous tune over an NA tune. That includes the TR6 or 7 with a very tight gap, some timing retard and some higher octane. Those things will account for 2-4% loss usually on a typical LS1. That maybe be from 10-25 hp loss depending on what octane and how much retard. But thats for very large shots as well and not needed for something like a 100 or 125 generally.
