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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

spark plugs

  • Thread starter Thread starter srjs28
  • Start date Start date Mar 30, 2010
S

srjs28

New Member
Jan 12, 2010
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Mar 30, 2010
#1
  • Mar 30, 2010
  • #1
i have not bought any type of "high performance" spark plugs for a vehicle since the split fires came out like 20 yrs ago. is there a plug that is recommended these days or will just a plain old autolite do?
 

BigmacK192

New Member
Apr 8, 2009
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Chicago.
Mar 30, 2010
#2
  • Mar 30, 2010
  • #2
E3 Diamond Fire is supposed to be the new hi-po plug, but I still run Motorcraft coppers in my 5.0. You don't need much else.
 

Cobra1741

Member
Mar 9, 2010
152
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16
Mar 30, 2010
#3
  • Mar 30, 2010
  • #3
ngk or motorcraft copper
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
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129
Mar 30, 2010
#4
  • Mar 30, 2010
  • #4
Another vote for Motorcraft copper.
 

tannerc91gt

This last 25% is foreign territory at this point
Founding Member
Nov 29, 1999
4,392
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Indiana
Mar 30, 2010
#5
  • Mar 30, 2010
  • #5
Autolite 23s for me.
Stock would be 25s.
Here's a decent reference sheet, it's a guide for nitrous plugs but you get the idea
nitrous plugs quick reference guide - Corral Forums
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,271
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Mar 30, 2010
#6
  • Mar 30, 2010
  • #6
Motorcraft copper.

Same plugs as autolite, but specs are rumored to be tighter. They are not made by the same company..but are made by same tooling.

If you have boost, or serious mods...NGK iridium
 
S

srjs28

New Member
Jan 12, 2010
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Mar 30, 2010
#7
  • Mar 30, 2010
  • #7
thanks guys, very helpful. since ive owned my fox (almost a year) ive turned to this forum for all my questions and 99% of the time they are answered and responded to with knowledge. thanks again.
 

Slatco

New Member
Jan 9, 2010
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Mar 31, 2010
#8
  • Mar 31, 2010
  • #8
Does anyone have any input on the Denso Irridium plugs? Richard Holdener ran them in the 427 Paxton supercharged motor in last months "Muscle Mustangs and Fast Fords"
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,271
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224
Massachusetts
Mar 31, 2010
#9
  • Mar 31, 2010
  • #9
The benefit of iridium plugs is that because it has such a high melting point, the spark plug tip is much smaller. As a result, less voltage is needed to actually cause the spark to "jump" the gap. It's less strain on the ignition system.

On a stock N/A car i would not bother...but get up there in mods or forced induction and i would go with Iridiums
 

Hi-Po

Member
Mar 31, 2005
106
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Oslo, Norway
Apr 1, 2010
#10
  • Apr 1, 2010
  • #10
After I installed the supercharger I had some slight detonation problems, but a set of Denso Irridium plugs took care of that. I was running the stock E7 heads then.
Last year I installed Trick Flow alu heads and went with a set of NGK copper plugs instead of the Denso plugs and they seem to work just fine. No detonation at least.

I remember the irridium plugs were incredibly expensive, but on the plus side they also had extremely long replacement intervals.

Anyways, I dont think you will gain any performance with irridium plugs, but if you are running high boost/spray then they may help with detonation/pinging.
Otherwise I would say go with good quality copper plugs.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,271
17,959
224
Massachusetts
Apr 1, 2010
#11
  • Apr 1, 2010
  • #11
Or silver plugs if you are like me and drive 500 miles/year
 

7upstang91

10 Year Member
May 30, 2008
936
124
74
Florida
Apr 1, 2010
#12
  • Apr 1, 2010
  • #12
Hi-Po said:
After I installed the supercharger I had some slight detonation problems, but a set of Denso Irridium plugs took care of that. I was running the stock E7 heads then.
Last year I installed Trick Flow alu heads and went with a set of NGK copper plugs instead of the Denso plugs and they seem to work just fine. No detonation at least.

I remember the irridium plugs were incredibly expensive, but on the plus side they also had extremely long replacement intervals.

Anyways, I dont think you will gain any performance with irridium plugs, but if you are running high boost/spray then they may help with detonation/pinging.
Otherwise I would say go with good quality copper plugs.
Click to expand...

I emailed NGK about this issue last month. They did not recommend the Irridium plugs at all. Just email them all you have and they'll help you out!
 
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