Spark plug Question
- Thread starter edi
- Start date
I just switched over to NGK BCPR 7ES and gapped 'em to .28. The car originally had 3923's gapped @ .40!! In both scenarios, idle was at 650, smooth, and under boost @ 15psi, the car was awesome. I will say that after fitting the NGK's, the car feels stronger - she got sideways the other day in a way I've never felt before, and outside temps. were similar to when I had the 3923's. I don't know if it was the diff. in plug, (the NGK's are colder), or the gap, but the car feels faster with the new NGK's.
BTW, thanks Sean for the recommendation to switch to the NGK's!
BTW, thanks Sean for the recommendation to switch to the NGK's!
woah, thanks supracentral. thats good info. so, you would use BKR6EIX-11 3764 if your running higher boost than stock, right? and one step colder would be BKR7EIX-11 3764, right?
edi said:
You are right on the heat range. But I would get the plugs without the "-11" on the end if possible. Running higher than stock boost you'll want a smaller gap. You can gap any plug down, but I'd rather start out closer to where I want to be and not have to stress it.
Also, anytime you mess with plugs, be sure you pull them and read them to see what the end result is. Reading the plugs will tell you if you have made the correct selection.
Seems like 90% of Supras I have encountered (including mine) have that slight miss at idle that is only audible through the exhaust... I have tried three sets of spark plugs (NGK, Autolite, Denso) and three different sets of plug wires (Prestoil, Sumitomo, and MSD), different igniter, wiring harness to coil packs...and my slight miss has improved a lot with my current setup: Denso plugs & MSD super conductors. I've gotten to the point where I don't even notice it even more, but it is still there.
I have one quick question for those of you experiencing the missing at idle:
How many of you are using a 3rd plug galley gasket?
I am not, and my 3923's are not missing at idle.
How many of you are using a 3rd plug galley gasket?
I am not, and my 3923's are not missing at idle.
I run 6097's NGK's but I also run a strong ignition. That too will also play a part in what plugs you use.
Duane
Duane
johnathan1 said:
Even my N/A does that. It's like a "plupp" sound. It's more apparent when it's cold, but I can still hear it a little when it's warm. I'm using NGK V-Power plugs. BCPR5EY-11 / 2441
BTW, can you say thread ressurection? :burnout:
This site has some awesome Spark Plug info, on Electrode Materials, Size Info, Reach, Gap, Resistor etc. on what ever plug you choose, it can also tell you what any particular part number will fit what vehicle etc. They even have a direct cross reference chart between all the brand names.
sparkplugs.com
sparkplugs.com
There are a couple of note that I have not seen addressed so I will address them
The MKIII Supra uses a spark plug that is a JIS height (53mm) when measured from the seat to the top of the terminal nut.
The MKIV Supra uses a spark plug that is an ISO height (50.5mm) when measured from the seat to the top of the terminal nut.
This means that the MKIV supra plugs CAN be used but it will be short and if the plugs wires can not go down any more will cause a loose connectiong that tends to pop off.
The MKIII Supra uses a spark plug that is a JIS height (53mm) when measured from the seat to the top of the terminal nut.
The MKIV Supra uses a spark plug that is an ISO height (50.5mm) when measured from the seat to the top of the terminal nut.
This means that the MKIV supra plugs CAN be used but it will be short and if the plugs wires can not go down any more will cause a loose connectiong that tends to pop off.
I currently have an 89 turbo with full 3 inch exhaust and intake. I need new plugs and wanted to switch to coppers. In the future I plan on upping the boost to 10psi. What should my gap be for ~7 - 10 psi on the copper autolites?