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best gap size for bpu supra

2814 Views 16 Replies 4 Participants Last post by  SpdRcr0
ok i have ngk 3330 ,6097 and some denso iridium plugs what the best gap size for the plugs .032,.034.035.040

my car is bpu
free mods
and boost controler

so what do you thing i should gap them too!???
1 - 17 of 17 Posts
stock gap is best. dont gap plugs yourself...because when you do gap your plugs, chances are the tip will not be at the right angle to the tip which will not be good.
stock gap fires the best and preduces the most HP. is you miss at stock gap, your ignition system is weak and you might need new coil packs. dont use NGK 3330/6097 no more, they are only a temporary solution.
we use 3330's NGK all the time and gap them at .032 if you keep wasting plugs the go back to stock #'s and you'll probaly need to replace your coil-packs. what kind of color is the ceramic on the old plugs and how far down on the threads of the plug are colored 1,2,3, threads down?
um who should gap them then !
Zerosoul said:
dont gap plugs yourself...

FRISBEE my plugs are ok what happen was bullshits left the coil pack loose when they worked on my car so i decided to change the plugs when i was in there anyway as they put stock ngk plugs in when i originally had denso iridiums!

any way i had my original denso plugs gaped at .032 bullish had the stock ngk plugs at .040

people have told me to gap them at .034 or .035 so now im confused a little !
with healthy ignition, you dont even need to touch your plug gap.
trust me I went thru this like you guys...when you talk to guys like Bruce Nomura, he will tell you when you gap the plugs yourself, usually the tip will be moved downward so its closer to tip then the back, which creats uneven spark. plus, the measurement is so small already, its hard to gap very plug at the same gap.
go get this IK22 Denso Iradiums thats 1 degree colder than stock at stock gap, if your car miss, change coil packs. I bet your car will run smoother than ever.
for most power, you want stock gap. for less power, go with smaller gap.

I dont understand why people like to take shortcuts to fix their problems....
I don't agree. I was missing at high boost. The plugs were new and at stock gap. The guy had them changed during the compression test when I bought the car.

I pulled them out and the gap varied from 37 to 39. I regapped them all to 35 and the car runs great. No more missing at high boost and a clean solid idle.

It's not always the coil packs IMO and it doesn't hurt to try the cheap solution first.

of course you need to make sure your plugs are all the same gap before you put them in. I'm saying dont gap it yourself unless necessary.
most of the time its coil packs. if your car runs good with stock plug and stock gap that means you have strong ignition and healthy coil packs.
cheap solutions are good, I tried that also, but when there is a way to do it right, why not do it right.?
zero thanks for the info i was told to use ik20 ,ik22 sound like the correct ones to use!
no problem! just giving back knowledge I'd obtained thru helps of other supra members.
yeh go with IK22, Randy at told me thats the one equals to #7 degree.
thanks all !
i will be testing a few plugs and some gaps and the ik22 to see what works best !ill pass the info to you all!
just put in some iridium gapped to .28 works flawless perfrectly smooth idle. BPU coming from the stock original plugs
I have read this debate a million times in the past and have went through about 6-7 sets of plugs on my last supra and here is the low down...
Zerosoul is right the larger gap the better (more low end torque especially).
Concerning what gap is best.....
IT ALL DEPENDS ON THE VARIABLES!! elevation, temperature, motor/coilpack condition, etc...
I ran my 1st supra with BCC, Exhaust, DP and the hose pulled from the wastegate (max boost 20 something psi) when i lived in northwest Georgia mountains using Champion C63YC (NAPA part #796?, ~$2.50 each) gapped at .040 with absolutely NO problems. But when I moved to the coast in North Carolina I had missing so i had to back off to about .036 to prevent miss. The Champions are colder than stock and the ground strap is pulled back away from the electrode more than NGK's, thus exposing more spark to the A/F mixture....i tried NGK's at the same gap but they missed.
go with whatever plug brand you want, and start at a gap of .035. if you miss go lower, if not go higher. it's better to start off with kind of a low gap and go from there (better to not miss if possible and go up until you miss ONCE then backoff a bit....much less crude than vice-versa)
just my .02.....i have tested this a lot, and i hope you can benefit from my testing. good luck and remember what works for someone else's car is just a guideline for your car - Supras are all different.
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thanks JeremyBlackwell
just trying to help
JeremyBlackwell said:
just trying to help
why not use NGK 6097? I thought they were good plugs...? Also do they come pregapped from the factory? Reason im asking is becuase I just got mine in the mail and im wondering if I should just plug them in or if i need to have them gapped properly.

... what if I just put the 6097s with the gap that they come with?
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