Spark plugs to suit boost

[TUF250]

i have been doing some reading and talking to some people regarding plug that are suited for turbocharged applications. i currently run the NGK platinum BPR5EP-11s in my straight gas 250 with a 0.85 gap set for gas as recommended by a gas tuner. overall i am very pleased with their performance. in regards to boosting a car i have been told that you should run a colder plug, in the case of ngk a 6 or 7 for higher boost leves which makes scense but i was also told that you should run a resistorless plug? why? also i it recommended to run a smaller gap such as 0.85 for turbocharged engines?

[PSI_LTD]

a resistor-less plug makes for a stronger spark, but only if you have an utter lack of computers in the car (something to do with feedback). a bp6es plug with a .9 gap worked well for me. i'm currently running splitfire plugs, and they are real crap. iridium plugs work well from what i've heard, but the plain ngk ones are great for the money. remember, you want the largest gap possible, while avoiding misfire. it also follows, that for higher boost, you would run a smaller gap, as excessive pressures can blow out the spark.

[ltd351t]

yeah what he said! I run one colder than std, I think ists the ngk6, something like that with factory gaps, no need to close them up unless your blowing out the spark, mine has std TFI dizzy and bosch transformer type coil, triggered by MS, with 19psi it wasnt blowing out the spark.

[XF0747]

im running a BP6ES (i think) and i got the gap at 26thou

[TUF250]

thanks guys, i was reading about the BP6ES as these are resistorless, cooler, have a shorter gap and conveniently are facotry plugs on the XE so they are easy to get.

[DINO]

go for BPR6ES's. the difference in performance is minimal im sure, and with the resistiors, you wont have to worry about reed back in ya radio and whatnot. mum had feed back from the plugs in her AU, made ticking and winding noises through the speakers matching what the engine was doin, hella annoying.

[PSI_LTD]

just add a line isolator in your power wire if you hear ticking in the stereo.

[drew442]

26 thou is .66mm, thats a tiny gap.

i think its 1 heat range for every 75-100hp you add.

the best 6 (195-220hp or standard power with gas) range plug without a resistor is the denso w20exu. which also has the extra projected insulator nose (anti fowling) and U grooved ground electrode (less quenching so you get a hotter burn).

i think they come as a 0.8mm gap, but you should regap anyway.

but boosted gas you might need to go a 7 heat range (or 22 in a denso plug) i dont know. best ask someone else :)

[windjackel]

i have tried a few plugs being that i work in spare parts the best i have found is NGK
BP7EY they are .8 gap standard and the Y means v groove where as the BP7ES are only standard tip. they cost the same price and the v tip gives you a better spark. ive had up to 25psi in my motor with out a miss, but i also run mallory ignition with a master blaster coil, and microtech computer. im hoping this set up will be good for at least 400rwhp if i ever get there.

[TUF250]

yeah 7s are the go for higher boost levels apparently. did you notice a difference from Ss to Y tips?