Spark plug question

eagleguy

Member
Newbie question. With the below listed modifications to my 86 T Type is there any plug brand or type that would be better than the Autolite 24's currently in the car gapped at 35 that I need to replace? Car has 26K and I am replacing plugs, wires, hoses, fluids etc.. Checked the plugs currently in the car and they seem to be OK, no fouling.

ta49 turbo
36# injectors
160 thermostat
100# comp valve springs
turbo tweak chip
fuel pump and hot wire kit going to it
 

SHADOWII

Well-Known Member
You are apparently running a safe tune if nothing is showing up in the performance or plugs, so I don't think it's necessary to change the plug type. however, you should have a scan tool to monitor the engine functions such as knock, etc. to avoid any possible damage and help w/tuning if you decide to up the boost. The majority run a scan-master.
I would also recommend a lot of reading and asking questions before tweaking.
 

626gn

Well-Known Member
You will get varying opinions on this. Try doing a search, it will make your head spin. Everybody seems to have a favorite plug they use and have their reasons for using it. FWIW I have used Autolite 24's, 23's (for higher boost), NGK, and AC Delco all at varying gaps from .035 to .028 depending on what boost I was running at the time. Never noticed a difference in any of them. I don't see anything wrong staying with the 24's for your build but if you want to quell your curiosity, plugs are cheap and easy to swap out.
 

NY Twin Turbo

All the good stuff.....Times 2.
If you are running higher than stock boost levels, I would tighten up a little on the gap. Maybe a hair more than 30 or so. With more boost, maybe even tighter still.
 

eagleguy

Member
Recently bought the car which has a Scan Master. Now I have to learn how it works. As far as the plugs, the only reason for the question at the moment is that the valve cover gaskets are going to be changed so I was going to do the plugs and wires which are original.
 

eagleguy

Member
Bought the Autolite 24 since everything seems to fine at the moment. Will try keeping the gap at the current 35.
 

scojack_2001

Livin' Like A Refugee
I ran the ACDelco CR43TS plugs gapped at .030" for years at ~20psi and no issues. Ran the NGKs for a while and saw no noticeable performance increase.
 

Nick Micale

Tech Advisor
Staff member
.......so I was going to do the plugs and wires which are original.

If the plug wires are original, be very careful when removing them as they are unique!

Only plug wires installed at the factory had the corresponding number for each cylinder printed on them.

Anyone restoring a GN would pay well for them if original.
 

Mr.Spool

Well-Known Member
With the below listed modifications to my 86 T Type is there any plug brand or type that would be better than the Autolite 24's currently in the car gapped at 35 that I need to replace?
it depends on boost level,if your running low boost the 24 should be fine,now you want to raise the boost up you should go to a colder plug (23) and tighten the gap low 30s.
 

gusszgs

Active Member
NGK UR5 is what I run but the plug you have will suffice.
Is there a thread I missed to the car you ended up getting? I know you were hunting for awhile. Congrats
 
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