spark plugs?
- Thread starter shdo69
- Start date
thunderkid84
Registered User
Autolite copper 103's gapped to .040
watch that 10%. It makes alot of heat
watch that 10%. It makes alot of heat
Why 103,s? Its a shorter plug. Wouldn't it not get enough spark?
kenewagner
Registered User
The 103s are used for high boost applications where the high pressures and boost blow out the spark. Im sure there is a better discription of that or I have left something out. I would just use a stock autolite plug and gap at
.040. If you are running 17, 18 or more lbs of boost go with the autolite 103s gapped at .035. Just my two cents
Ken
neverfastenough
Registered User
Also, the stock plug with the longer end, gets really hot from combustion chamber heat. I cant see that helping with an unwanted ignition other than the primary one, so eliminating that is a plus, with something such as a autolite 103 or ngk TR6...
Corey
Corey
Last edited:
David Neibert
SCCoA Admin
Casey,
I've got a set of those same plugs but haven't installed them because I'm told they are two ranges colder than stock and will likely foul out with normal street driving. Dave suggest them to me for track use only.
I'm currently using copper 103s (one range colder than stock) gapped at .035, and they seem to be working well.
David
i have a sc set up in my mustang. I have the app103 plugs(double platnum) gapped at .035" and am running about 10-11lbs of boost. At higher rpms 5100 + wot the car sputters like there is no spark. Runs fine under 5100 rpms. I also have a scremin demon coil and ford racing 9mm wires. Should i start with a new coil or try different spark plugs?
Mike8675309
Registered User
Maybe you are way too rich? The double platinum doesn't conduct as well as copper either, it's just there to resist wear. I run the A103 copper plugs gapped at .035 and see 19psi of boost with no problems. At .045 I was seeing spark blowout start around 5100rpm.
the a/f ratio is 10 somthing. however my buddy did the same swap with his car has the same tune and has the same a/f ratio as mine but dose not do it. I know before the swap (using the stock mustang plugs) no problems. would running a double platnum plug vs a copper plug cause this problem?
Mike8675309
Registered User
I wouldn't say cause, perhaps lead to. 10 is pretty rich, and early on in tuning, a 10 AFR on my car caused obvious ignition issues as the air started really moving. Stock coil, Motorcraft plug wires. There is no need to use the double platinum plugs unless you don't intend to change the plugs very often. I put a new set of plugs in every year. This year I did two sets just because I was reading the plugs and the standard copper are cheap enough to put in fresh ones. I kept the ones I took out as spares.
Under high boost you can actually blow the platinum tips off. I use non-platinum Autolite 103s gapped at .035
The non-platinum 103s are cheaper,which helps because I like to change the plugs every 4 months.
Justin not doubting you, but could you explain what about the plugs would cause it?
Douglass
Hock
Registered User
Maybe spark blow out do to the higher boost levels seen at the higher RPM's