What spark plug to use in a 12A?

t_g_farrell · 12-21-2011, 03:11 PM

So I've been using stock NGKs in my 80 GS SA 12A stockport. I've got a better
ignition system cobbled together and it has proven very reliable and powerful
compared to the stock or a 2GDFIS that I had before. I call it TFIDFIS only
because it uses some Ford TFI truck coils and GM HEIs for the ignitors. I run
leading only with no trailing and it can start my engine even when flooded.

I have a discussion on the other forum for that so I won't go into it here in
detail. Maybe I'll pull it over and post it here if theres interest.

I'm thinking I can get a bit more of an edge out of a better spark plug next time
I change em. I used to hear that 2G plugs were the best but now I understand
that maybe Rx8 plugs are actually the best. I'd loved to see some folks on here
weigh in and discuss it. I haven't made up my mind yet but I'd love to see if
anyone has numbers that can prove one plug is better than some other.

13x · 12-21-2011, 10:44 PM

I for one am curious for more info on the setup,

We had a local run the RX8 plugs for leading and the stock 12A for trailing he said there was a differance but ... well I can't confirm ... the thing is if I remember correctly the plugs for the 8's are nearly $30 ... each

t_g_farrell · 12-22-2011, 10:22 AM

Yeah, the rx8 plugs aren't cheap but if it works better and lasts longer it may be a win.

djmtsu · 12-22-2011, 12:48 PM

I always used FC plugs.

sen2two · 01-29-2012, 07:26 PM

I only used NGK B9ES plugs for years. Not many people know about these, but I learned about them from a well known Rotary guy in my area when I first got into Rx7's. They are only 2 dollars each and are almost impossible to foul. Served me well for many many different types of set ups...

But I now prefer to run Rx8 plugs in everything.

t_g_farrell · 01-30-2012, 09:44 AM

Whats the part number for the rx8 plug that is working for you sen2two?

Wheres the best place to get em for a good price? Anyone?

I was hoping some one could come in here with dyno results or maybe a
technical description of why they work better or both

Not that the
testimonials aren't welcome, I like to hear about the experiences.

JL1RX7 · 01-30-2012, 09:52 AM

I will look at mine when I get home, but I think they are 6401,6411. I get them at advance. Two year warranty. Order online pick up in store. Sometimes they have 15% or 20% and 50 bucks off your next online order.

12-21-2011, 03:11 PM	#1
t_g_farrell Waffles - hmmm good Join Date: Aug 2008 Location: Huntersville, NC iTrader: (0) Posts: 757 Rep Power: 0	What spark plug to use in a 12A? So I've been using stock NGKs in my 80 GS SA 12A stockport. I've got a better ignition system cobbled together and it has proven very reliable and powerful compared to the stock or a 2GDFIS that I had before. I call it TFIDFIS only because it uses some Ford TFI truck coils and GM HEIs for the ignitors. I run leading only with no trailing and it can start my engine even when flooded. I have a discussion on the other forum for that so I won't go into it here in detail. Maybe I'll pull it over and post it here if theres interest. I'm thinking I can get a bit more of an edge out of a better spark plug next time I change em. I used to hear that 2G plugs were the best but now I understand that maybe Rx8 plugs are actually the best. I'd loved to see some folks on here weigh in and discuss it. I haven't made up my mind yet but I'd love to see if anyone has numbers that can prove one plug is better than some other. __________________ 1980 GS stockport, Fat Nikki, RB Dual Facetfuel pumps, Holley regulator, RB Street port exhaust, 2GDFIS, MR2 MK I electric fans, 2G strut bar, relayed fans, lights and fuel pump, LEDs Project Fat Nikki Budget 12A rebuild Video setup < $30.00

12-21-2011, 10:44 PM	#2
13x SinCityRotary Join Date: Feb 2010 Location: Sin City iTrader: (0) Posts: 207 Rep Power: 15	I for one am curious for more info on the setup, We had a local run the RX8 plugs for leading and the stock 12A for trailing he said there was a differance but ... well I can't confirm ... the thing is if I remember correctly the plugs for the 8's are nearly $30 ... each __________________ WHiV8 in the works!! May 2015 Email Last edited by 13x; 12-22-2011 at 11:45 AM..

12-22-2011, 10:22 AM	#3
t_g_farrell Waffles - hmmm good Join Date: Aug 2008 Location: Huntersville, NC iTrader: (0) Posts: 757 Rep Power: 0	Yeah, the rx8 plugs aren't cheap but if it works better and lasts longer it may be a win. __________________ 1980 GS stockport, Fat Nikki, RB Dual Facetfuel pumps, Holley regulator, RB Street port exhaust, 2GDFIS, MR2 MK I electric fans, 2G strut bar, relayed fans, lights and fuel pump, LEDs Project Fat Nikki Budget 12A rebuild Video setup < $30.00

12-22-2011, 12:48 PM	#4
djmtsu My minds tellin' me no... Join Date: Feb 2008 Location: Murfreesboro, TN iTrader: (10) Posts: 4,043 Rep Power: 21	I always used FC plugs. __________________ 1976 Mazda Cosmo RX-5 1976 Mazda Cosmo RX-5 2003 Toyota Tundra TRD 2015 Toyota 4Runner SR5

01-29-2012, 07:26 PM	#5
sen2two KTEC Join Date: Jan 2009 iTrader: (2) Posts: 642 Rep Power: 0	I only used NGK B9ES plugs for years. Not many people know about these, but I learned about them from a well known Rotary guy in my area when I first got into Rx7's. They are only 2 dollars each and are almost impossible to foul. Served me well for many many different types of set ups... But I now prefer to run Rx8 plugs in everything. __________________ what I have: 1985 Gs:12a All motor Drag car - 1973 Rx2: Play car What I had: 93 Touring: TRADED - 91 Coupe: TRADED - 90 GTU: RHD - 88 10AE: SOLD - 87 Base: SOLD - 86 Base: SOLD - 1985 GSLSE - 85 Gsl: SOLD - 80 Gs: TRADED - 1972 Rx2

01-30-2012, 09:44 AM	#6
t_g_farrell Waffles - hmmm good Join Date: Aug 2008 Location: Huntersville, NC iTrader: (0) Posts: 757 Rep Power: 0	Whats the part number for the rx8 plug that is working for you sen2two? Wheres the best place to get em for a good price? Anyone? I was hoping some one could come in here with dyno results or maybe a technical description of why they work better or both Not that the testimonials aren't welcome, I like to hear about the experiences. __________________ 1980 GS stockport, Fat Nikki, RB Dual Facetfuel pumps, Holley regulator, RB Street port exhaust, 2GDFIS, MR2 MK I electric fans, 2G strut bar, relayed fans, lights and fuel pump, LEDs Project Fat Nikki Budget 12A rebuild Video setup < $30.00

01-30-2012, 09:52 AM	#7
JL1RX7 Rotary Fanatic Join Date: Feb 2008 Location: Front Royal, VA iTrader: (1) Posts: 487 Rep Power: 17	I will look at mine when I get home, but I think they are 6401,6411. I get them at advance. Two year warranty. Order online pick up in store. Sometimes they have 15% or 20% and 50 bucks off your next online order.