81WideMariah

iTrader: (8)

So I'm FINALLY nearing the end of my 12a Turbo build and wanted you guys to weigh in on which spark plugs to run. I was doing a little homework on sparkplugs.com and I'm thinking the gap on stockers (NGK's) is going to be a little too large for the boost I'll be running. So I'm looking at other options.

I'm pretty well settled on using Trailing plugs in the leading and trailing as they are a little colder plug and, again, with the boost I'm running, a colder plug is going to be a requirement.

So I'm torn between running T2 trailings on all 4 holes or RX8 Trailings.... leaning towards the RX8's, but at $20 a plug I'd rather not use them if they' re not magical and amazing... But the T2 plugs have a slightly longer reach (around 2mm) than the stock 12a plugs which will slightly increase the compression ratio, which is obviously not a good thing under boost.

So let's hear what say ye... vote above and post your thoughts below.

cshaw07

iTrader: (14)

im also building a turbo 12a but im not close to finishing mine yet. I do remember reading somewhere that the T2 plugs were good in the leading and the stockers in the trailing. Im not sure where I saw that, but thats what im going to do. Unless someone comes on here and says that my car will explode creating a black hole or something if i use them. haha

j9fd3s

iTrader: (3)

here is how i see the spark plug choices. you have 3 design choices, and then you pick a heat range. the FC/FD/rx8 always run a colder heat range plug in the trailing, this is the first possible "hot spot" that the incoming air/fuel charge sees, so IMO if you go from 7 to 9's in the leading, you should go from 9 to 11 in the trailing.

design #1. is the stock 4 ground strap style plug. they come in 2 heat ranges, the 12A runs 8 (i think) all the way around, and the gsl-se runs 9's all the way around. if you are using a stock distributor ignition these are a good choice, as its stock. with a turbo, you want the cooler plug, which is a stock GSL-SE plug.

design #2. is the FC/FD plug. these are easier to get, and come in a 7 heat range and a 9. in a turbo you want the 9's, these work with a distributor, but they are the least optimal IMO.

design #3. the rx8/race style plugs. these plugs take less power to fire, which is good. mazda also uses this design in the rx8 because it misfires less than the FC/FD plug. the rx8 and the race plugs are essentially the same except for the heat range, the rx8's come in 6,7,8,9 and the race are 10, 10.5 11 and i think 11.5. the downside is price, $30 a plug is a lot....

design #4, the tuning plug. the autolite plug for the FB is $3 each, if you're tuning from scratch you can foul 10 sets of these tuning the car before you buy 1 rx8 plug...

so anyways, if i had a turbo car, and it was tuned, i would probably run 10 or 11's race plugs in the trailing and something in a 9 in the leading.

Rotospeed

iTrader: (8)

if you upgrade the ignition ie; msd box and coils, the biger gap of the fb plug is not a problem.

rx71king

iTrader: (6)

i uses bur9eqp in my 12a all around..