Spark plug ? Gn1 heads and meth injection.

434nova

Active Member
What plugs are u guys using for your gn1 heads with methanol injection? I am using a autolite 104 but I am worried about the extended tip and alcohol. I swspped to a 3933 and i fouled the plugs up fairly fast. Should I swap to a 3932 or stay with a autolite 104? Also what style plug does the gn1 heads use. A gasket type or a tapper plug? I am running 26#s of boost and alcohol injection. Thanks
 

bad V6

Member
NGK 4554 gapped at .024 burning a 50/50 mix of 93 and 110 with alky, 30+ # and 0 knock. It will have a lot to do with your tune and the condition of the motor.
 

vacuum 6

I have chuckers
Around 600 rwhp. I'm wanting to up the boost closer to 30#s. Trying to get this te45a turbo all in.
From my understanding 100+ HP/hole non-projected plugs are recommended. For three years I've run AR3934, lots of street miles zero issues, with out of box gap.
 

Coach

Bo ran away with my goat :(
Do you do street driving on them? Any issues with fouling out? How much boost? Are you using meth? Thanks
Yes. I only street drive on 93/Alky. No issues at all. Plug recommendation was by Cal Hartline
 

No disintegrations

Well-Known Member
From my understanding 100+ HP/hole non-projected plugs are recommended. For three years I've run AR3934, lots of street miles zero issues, with out of box gap.
Isn't that the stock heat range? ( The last digit for autolite)

Edit: I see stock is a 5
 
Last edited:

GG87GN

Member
From my understanding 100+ HP/hole non-projected plugs are recommended. For three years I've run AR3934, lots of street miles zero issues, with out of box gap.
Can I run ar3934 with stock computer? Non resistor plug?

Sent from my SAMSUNG-SM-G920A using Tapatalk
 

No disintegrations

Well-Known Member
Ar3924 is resistor version of that plug. You most likely need resistor type for stock ecm application.
If the second to last digit is odd they are non resistor, even is resistor. For autolite brand.
 
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