Planning on running one of the above plugs for my NA 12.5:1 compression 1.8L motor.

Searched on the forum for the best plug to use and came across both the #4554 and #7173.

Which is recommended?

Both are of V-Power Racing plugs, 14mm, 3/4" reach, 5/8" hex, gasket seat, non-resistor.

Difference is:

#4554 is a non projected tip


#7173 is a projected tip


I would think that NA setups would use the projected tip and FI would use the non projected.

What are your thoughts on the plug types.

 

I think non projected for N/A and projected for FI

 

Ok, seem to have it backwards.

Any reasons why NA use non-projected and FI use the projected?

 

for clearance reasons. Ever seen a high-dome piston hit the spark plug?

 

Is that the only reason for use between projected and non-projected plugs?

Anyone else.

As I view many post regarding plugs such as the traditional type NGK BKR7E and BKR7E-11, they are all projected and used on high comp NA motors.

Additionally, the modified spark plugs from Rocket are also projected type, I would assume that if the pistons hitting the plugs was such a concern, then Rocket would have modified a non-projecting type plugs instead....

Haven't come across a post debating between projected and non-projected plugs.

I guess just to be on the safe side, I'll get some #4554. Thanks...

 

From what I understand the projected tip in a shallow pentroof chamber (most hondas) interferes with the flamefront due to the depth of the plug.(I run the R5671A-8) I don't fully understand the reasoning, but in an old SCC magazine they had a project sentra with a 200hp na sr20de (which has a very similar chamber) and they recommended against running an extended tip plug because they lost a couple hp on the dyno and they theorized the depth of the tip issue. Anyone who really knows want to chime in?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by d16dcoe45 &raquo;</TD></TR><TR><TD CLASS="quote">From what I understand the projected tip in a shallow pentroof chamber (most hondas) interferes with the flamefront due to the depth of the plug.(I run the R5671A-8) I don't fully understand the reasoning, but in an old SCC magazine they had a project sentra with a 200hp na sr20de (which has a very similar chamber) and they recommended against running an extended tip plug because they lost a couple hp on the dyno and they theorized the depth of the tip issue. Anyone who really knows want to chime in?</TD></TR></TABLE>

Interesting? What issue od SCC was that? I should have it.

 

I got some NGK Racing Plugs R7433-8.

Comes in a box set like


They are of Iridium center and standard projected type. These were recommended by and used by tuners in Japan.

Anyone try plugs like this?

It's different compared to the V Power race plugs.

No other input on projected and non-projected plugs???

 

I jsut use BKR7E's!

 

I got a set to try at no expense, friend sold his ride and had a spare set, but just ordered some R5671A-8 (#4554) since they are more affordable, under $3.

Just checked the price on the NGK Race Plugs R7433-8, they go for a whopping $38 each.

That's some crazy price for plugs.

Hey hybrid_vtec, what compression you running the BKR&E's with?

 

Has anyone experienced problems running the non-resistor style plugs? Any type of interference?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybrid_vtec &raquo;</TD></TR><TR><TD CLASS="quote">

Interesting? What issue od SCC was that? I should have it.</TD></TR></TABLE>

I don't remember exactly, I have it somewhere in a pile--Its probably from late '99 early 2000. It was when they had that project sentra (b14) it was turqoise with yellow enkei rpo-1s on it. They were trying to match the power and performance of the dc2 type r. The car has long since been retired.

 

think about it, a projected plugs electrode is futher down in the chamber, a non projected is recessed in the housing of the plug as you can see from the picures, now heres the common sense part, which is going to detonate easyer one with the electrode buried or the one thats out in the open? i reccomend ngk 2975 most places dont have them in stock but can order them they are what a skunk2 tech recommended to me

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DEMNTD1 &raquo;</TD></TR><TR><TD CLASS="quote">I got a set to try at no expense, friend sold his ride and had a spare set, but just ordered some R5671A-8 (#4554) since they are more affordable, under $3.

Just checked the price on the NGK Race Plugs R7433-8, they go for a whopping $38 each.

That's some crazy price for plugs.

Hey hybrid_vtec, what compression you running the BKR&E's with?</TD></TR></TABLE>

I run 11.52:1 static compression.

Now what is the make up of the 4554? Why it is so good to run?


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nateg &raquo;</TD></TR><TR><TD CLASS="quote">think about it, a projected plugs electrode is futher down in the chamber, a non projected is recessed in the housing of the plug as you can see from the picures, now heres the common sense part, which is going to detonate easyer one with the electrode buried or the one thats out in the open? i reccomend ngk 2975 most places dont have them in stock but can order them they are what a skunk2 tech recommended to me</TD></TR></TABLE>

The 2975's, what is the actual part number? Wy did Skunk2 recommend them?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybrid_vtec &raquo;</TD></TR><TR><TD CLASS="quote">

I run 11.52:1 static compression.

Now what is the make up of the 4554? Why it is so good to run?
</TD></TR></TABLE>

For one, I'll be running 12.5:1 compression, so the 4554 VPower is of 8 heat range.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybrid_vtec &raquo;</TD></TR><TR><TD CLASS="quote">

The 2975's, what is the actual part number? Wy did Skunk2 recommend them?</TD></TR></TABLE>

I sourced the part number from NGK, it is ZFR7F-11 and looks like:

This plug has an extended projected tip.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nateg &raquo;</TD></TR><TR><TD CLASS="quote">think about it, a projected plugs electrode is futher down in the chamber, a non projected is recessed in the housing of the plug as you can see from the picures, now heres the common sense part, which is going to detonate easyer one with the electrode buried or the one thats out in the open? i reccomend ngk 2975 most places dont have them in stock but can order them they are what a skunk2 tech recommended to me</TD></TR></TABLE>

So according to "nateg", a non-projected plug (#4554) will detonate easier compared to the projected plug (#7173). So it is optimal to get and extended projected tip (#2975).

Any thoughts???

So what compression did S2 recommend the #2975's for?

 

Would I see any benefits from switching from the plugs I have now(BKR7E)?

 

Depends on your setup and how your current plugs are running. Most people who run high compression, 12.5:1+ run heat range from 8 to 10.

Initially I was told to use 10 heat range, but usually it is for circuit vehicles who run lap after lap, but since I will be using it for drag racing, 8 heat range will be fine.

If the plugs are running hot, then going to 8 heat range could give you a couple hp's. It all depends. Try picking up a set of #4554, its only like $2.39 and give it a try.