spark plugs

[turbobuick]

Chris, how often do you change your plugs? And have you done any comparison of non-resistor to resistor plugs in your car?

On the TSO motor every race some times more if we want a clean read on them. We will check them several times a race. After a race I leave them in to idle the car around or if I take it to a car cruise and drive it around. They never foul out for driving around BUT I never drive on the street with any real boost either

I never ran a resistor plug and there is a reason why but I dont recall what it was at this point.

 

[norbs]

Here is a non car related article on resistor vs non resistor. Seemed quite interesting.

Resistor spark plugs - resistor spark plug caps.


Looks like the 5k ohm resistor is not going to have an ill effect?

 

[turbobuick]

Here is a non car related article on resistor vs non resistor. Seemed quite interesting.

Resistor spark plugs - resistor spark plug caps.


Looks like the 5k ohm resistor is not going to have an ill effect?

I don't recall what the issue is but I don't think you want to run a resistor plug with a CDI ignition.

 

[norbs]

I don't recall what the issue is but I don't think you want to run a resistor plug with a CDI ignition.

I read that too somewhere, but according to MSD for a msd7 box its not an issue.

Doing more research it appears non resistor do give maximum spark, but the trade off is plug life compared to resistor pluugs. I will post some pics of my non resistor plugs after 200 miles of normal street use.

 

[norbs]

Here's a pic of what i been using before autolite AR3934 Non resistor. I would say the gap has opened at least .005 in street 200 miles. But it is hard to measure becuase of the back cut ground strap.

 

[norbs]

Here is a brand new plug for comparison.

 

[Alky V6]

Now this is a regular nose, fat cutback side electrode, very cold plug.

 

[Alky V6]

Time to change out the plugs.
Plug fouling?... What's that?

 

[norbs]

They look like new, wow what are those AR3931's? ALky sure burns clean.

 

[Alky V6]

They're Champion plugs.
I did start out with NGK, but I'm having better luck with these.
The shorter and fatter the ground electrode the better. At least in my particular circumstance.

 

[TurboBuRick]

Threw in some ngk R5671A-9's last night. They are the middle of the offered heat range. Idles fine. I'll keep going down and see how it goes. My car primarily street driven but like to run the big boost. :biggrin:


RL

 

[pacecarta]

old thread but does any one have a preference for a plug for the TA Eliminator heads running E-85 mid 20s boost on a 274 stage 2 (also has the TR6 ignition)

 

[lazaris]

old thread but does any one have a preference for a plug for the TA Eliminator heads running E-85 mid 20s boost on a 274 stage 2 (also has the TR6 ignition)

NGK 5671A-8 over 25psi go to a -9

 

[pacecarta]

thanks Ralph

 

[lazaris]

thanks Ralph

Welcome.

 

[norbs]

Just doing some reading ........using resistor plugs with a CD ignition actually increases spark duration slightly, but not sure if its true.

 

[Nick Micale]

old thread but does any one have a preference for a plug for the TA Eliminator heads running E-85 mid 20s boost on a 274 stage 2 (also has the TR6 ignition)

From what I see about the NGK 5671A-8 plug, it is an extended tip?

The Autolite racing plugs have proven to work very well in the E-85 applications we have experienced, and would NEVER want an extended tip plug in an application like yours.

A local E-85 600 HP T-Type recently dynoed over 600 HP at the rear wheels using Autolite AR-3931 plugs.

By contrast, a low 10 sec. GN just burned out nos.1 & 2 plugs extended tip plugs on an easy 10 sec. pass. Had he made another run, there would have been extreme damage?

If a hot spot is going to develop in a cylinder, it is almost always the spark plug, so it is best to use a non-projecter plug in a high boost, high HP application. Actually, in any boosted application, I do not want a projected tip plug.

 

[lazaris]

From what I see about the NGK 5671A-8 plug, it is an extended tip?

The Autolite racing plugs have proven to work very well in the E-85 applications we have experienced, and would NEVER want an extended tip plug in an application like yours.

A local E-85 600 HP T-Type recently dynoed over 600 HP at the rear wheels using Autolite AR-3931 plugs.

By contrast, a low 10 sec. GN just burned out nos.1 & 2 plugs extended tip plugs on an easy 10 sec. pass. Had he made another run, there would have been extreme damage?

If a hot spot is going to develop in a cylinder, it is almost always the spark plug, so it is best to use a non-projecter plug in a high boost, high HP application. Actually, in any boosted application, I do not want a projected tip plug.

It is NOT a projected tip.

 

[forcefed3.8's]

AR3932's here. They are fine on the street, but when the center electrode gets rounded off, it increases the gap, and will break up under boost. I always race with a fresh set of plugs.

 

[ttypewhite]

AR3932's here. They are fine on the street, but when the center electrode gets rounded off, it increases the gap, and will break up under boost. I always race with a fresh set of plugs.

I second that. I sometimes run the 103 Autolites on the street too