TURBO383WS6

iTrader: (2)

looking for someone to point me in the right direction for a plug to fit an lt1 head at approx. 1200 hp. tuner believes we're blowing the spark out on my TR6's so he thinks something equivalent to an ngk 9 is what it will take. is this too cold or about right? any help would be greatly appreciated

Phil99vette

iTrader: (11)

3911s

InconFormula

iTrader: (7)

x2 autolite 3911 or a slightly colder 3910.

veee8

iTrader: (40)

Well what is the 3933 equivalent to?

98Z28CobraKiller

iTrader: (17)

TR6's are good to about 450-500 rwhp. I ran #8's on motor and spray with about 500 rwhp motor and 800ish on spray. I still run the #8 (ngk 7317's for the LS1 head gapped @ 025) on my stock LQ9 with a PT88 pushing about 16 psi (guessing 625ish rwhp). I daily drive on that plug aswell without issue.

Fireball, are those 3911's recessed tips? The 3910 is colder? Seems like it should be the other way around.

TURBO383WS6

iTrader: (2)

found a set of NGK 5673-9's which are basically the same as the 3911's from what i was told. if these don't work, i'll give the autolites a try. thanks a million guys, couldn't have found em around here w/out your help. hopefully these will solve the problem. everything was fine at 20psi, but anything over that would start "missing".

Fireball

iTrader: (21)

3910 and 3911 are projected tips.

3933 (what I run) is non-projected

98Z28CobraKiller

iTrader: (17)

I will be switching over to that style plug once I get the forged motor in and start turning it up. Seems like a better way to keep the spark from blowing out.

93formto98T/A

iTrader: (28)

Shawn @ VA Speed advised me to go with AR103s for my 1200rwhp motor. Any others using these?

Phil99vette

iTrader: (11)

If he said go 103s than go 103s.... That plug is a:
14mm Thread
18mm (.708") Reach
5/8" (16mm) Hex Size
Tapered Seat, Resistor
Power Tip
Copper Core
Racing Plug with Nickel Plated Shell
Heat Range 3

Sounds pretty damn close to our 3911-3933s just a different reach.

The 3911s I ran last year are...
14mm Thread
19mm (3/4") Reach
5/8" (16mm) Hex Size
Gasket Seat
Non-Resistor
Power Tip
Copper CoreR
Racing Plug with Nickel Plated Shell
Heat Range 1

Shawn @ VA Speed

iTrader: (3)

for heads using a stock style plug-the 103's are the right choice
for heads using the 3/4 reach gasketed plug-the 3933's are the ticket-the 3911's are good but for a f/i motor i don't like the projected tip

HUNTER02SS

iTrader: (24)

I use AR3934's. They work well for me, but seem to be a little on the rich side while just driving normal(if that is possible).

koolrayz

iTrader: (26)

Anyone use the AR473?
I have taper seat heads.
I guess I am a little confused with using a 103, thats equal to a tr6. I was using a projected tip tr8 with under 800 on nitrous.
I would have thought a tr9 equal would have been a good staring point at the 1000rwhplevel with my new turbo setup?

MIGHTYMOUSE

iTrader: (59)

i use ngk 7173 (gastket seat for all pro's), always had a misfire after about 1 oil change with the ar 3911's

4SFEDZ

iTrader: (6)

what gap do you run?

MIGHTYMOUSE

iTrader: (59)

28 or 30, havent seen my plugs since october when i put a fresh set in for the memphis shootout

SuperZ

iTrader: (2)

what would those be similar to on a TFS head without gasket?NGK TR8?

SuperZ

iTrader: (2)

ttt
for 20psi

TURBO383WS6

iTrader: (2)

after a little testing w/ the TR9's, the hesitation and stumble i was getting is gone at 25 psi. guess my tuner dude knew what he was talking about after all. thanks for the input guys.

MIGHTYMOUSE

iTrader: (59)

ya something like that, i believe you can use the same plug just not the other way round