Turbo question : Spark plugs

[Phoenix]

On the shogun , im running Motorcraft fine wire (stockers)

And Ive heard about running a cooler plug? Please elaborate and what you guys got installed in your turbo sho?

 

[zblackbeast]

From my reading most people just go one range colder. What that part number is off the top of my head i'm not sure.

 

[91PDXmocha]

Autolite #3923's

 

[zblackbeast]

Stock is 3924, correct. So autolite just losses one number for the heat range? If thats the case I can assume that the 392x series will all work in an SHO, obviously being an incorrect heat signature?

 

[Sho Amo]

How much boost are you going to run? These cars love to blow spark out.

Here is my recommendation, although some may disagree.

For every 1psi of boost added, subtract .0013 from your plug gap.

Starting at .044

6psi=.036


Note: This isn't any general rule of thumb, and there are many variables to the situation. This is what worked for me, on a weak ass COP ignition system. I still started to have issues beyond 12psi even gapped under .028

If you don't plan to run more than 10psi, the COP system is fine. Any more than that, you will either need to return to EDIS w/single coil pack or run Kenne Belle's boost a spark.

 

[rubydist]

which cop coils were you using, Sho Amo?

 

[bigblock]

I run 3923 copper for n2o. I started with 3922 and could tell I wasnt getting a full burn. on spray it was fine but too cold off it. So 23 if your low boost should work fine. I did notice my low end droped off some when I changed plugs on 87. 91 feels the same as before I changed them.

edit 11/2/12: found out my loss of low end was due to a dieing o2. still seems more peppy on 91 oct though.

 

[Phoenix]

Im planning on big boost , I got a garrett GT35 hybrid. built by a guy that does only that. A similar one to mine made 480 whp in a nissan v6 (3.0 fairlady Z) single turbo.

I hope to get 400+.

 

[SHOspazz92]

3923 in the blower car gapped at .25

 

[Phoenix]

Thread revive

Copper or irridium ? Is there a technology to avoid when turbo?


Can I buy a colder Motorcraft? I just hate Autolites....

 

[91PDXmocha]

You know who makes Motorcrafts plugs right ? Autolite .

I would stick with copper and just check/change then more often.

 

[yamahaSHO]

Either will work. Iridium is what all the boosted Subarus run from the factory. I wish I had not changed my iridium for copper on my SHO simply for the service life.

Pretty sure all of this has been covered before.

 

[SHOtime2511]

Copper 3923 here.
IDR what the gap is set to 28-30ish.

 

[Sho Amo]

which cop coils were you using, Sho Amo?

Sorry, never saw this.

I was running the coils from a 4 cylinder focus.