Thread: How To: Side Gap Spark Plugs

Stock gap is .039 on coppers, reduce by .010, .029. Though on NA motors I would try .039 on coppers still.



Definitely let us know

So properly converted:

0.039 inches = 0.99 mm?
That's a small gap

Almost one cm, not too small

Actually, 0.99 mm is almost 1 mm, and 10 mm is 1 cm :P.


Anyways, did this yesterday, and the car runs noticably smoother. Combined it with indexing them.

Went through 8 plugs though, 4 of them were usable, 100% indexed.

Oh crap missed that .

It doesn't need 100% perfect index. Just make sure the the ground electrode is in 3 O-clock to 9 O-clock area .

Anyone tried these ones? NGK Spark Plugs R5671A-11 X-Cld Race 14mm x3/4",5/8"Hex: eBay Motors (item 200525236189 end time Oct-29-10 05:52:44 PDT)

Wow very nice, I would be curious to actually them out. Though I don't know if it's worth paying almost twice the price per plug.

I'll take a look and see if I can find some 7e's that would work for us.

EDIT: I'm kind of liking these actually. http://www.ngksparkplugs.com/products/spark_plugs/racing.asp?mode=nml

EDIT 2: Found the Ones that should work for us. Using This Guide, if we match our current plug BKR7E then we will find R5672A-8 (NGK #7173). I did a quick search and it seems to match SR20DET (RWD) which seem to use same BKR's. I'm going to get a set and try them out .

Its interesting - those plugs are extremely simialr to the Greddy NGK plugs used for race cars back in the day!

Ordered a set from Greg, will be here in a few days

Edit: Got the plugs from Greg (which btw was super fast). The R5672A-8 (NGK #7173) are regular ground electrode ones. They look the same as the regular V-power plug. I wonder if it's like that because they are V-power plugs (seems impossible to find non V-powered ones).

Be very careful when looking and purchasing the Racing plugs, it seems like most of them do not have resistors. Without the resistor you could fry the ignition system.

I just got off the phone with Greg V and we looked at R5672A-8 (NGK #7173), it does not have a resistor. We also looked at R5671A-7 and it also didn't have a resistor.

To top it all off, both of those racing plugs have the same ground electrode as regular Coppers. They do not have the "side gapped" ground electrode that we are shooting for.