ttocs
Post Whore
As the title says I seem to keep finding my plugs black as hell even though AFR was showing ok. With a supercharged 5.0 running trickflow 170 cc heads what plugs and gap would you recommend?
should I change the plug or gap if I keep fouling plugs?
- Thread starter ttocs
- Start date
What afr are you running and what gauge are you using? Did you make sure the gauge is calibrated correctly and do you have another wideband you could install to compare against?
Also, a lot of idle time will foul your plugs if you aren’t driving it around. A lot of start up cycles can foul them too as there is extra fuel added on start up and it will run rich until the oxygen sensor heats up and come on line completely.
Also, a lot of idle time will foul your plugs if you aren’t driving it around. A lot of start up cycles can foul them too as there is extra fuel added on start up and it will run rich until the oxygen sensor heats up and come on line completely.
Yeah what warrior said............so start driving already!!!!!!!! [emoji6]
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
OP
OP
ttocs
Post Whore
I have two AFR gauges, one with the Holley hp and the plx devices afr on the other side. They do tend to read a little bit off from one another(.5-1ish) but when I mentioned it to my remote tuner he was not concerned. So far 99% of it running has been in the garage. What plug and gap would you recommend just out of curiousity?
Honestly, I really don’t know what plug to run in that setup. I’m not too familiar with running boosted pushrod setups.
I know gauges aren’t going to read the same, that’s just how it is. .5-1 point I guess isn’t the end of the world. What is your target afr at idle?
I know gauges aren’t going to read the same, that’s just how it is. .5-1 point I guess isn’t the end of the world. What is your target afr at idle?
Low rpm driving and idle can be heavy on the lean side with no negative affects. Especially aluminum heads.
You gotta find that afr area where the plugs are self cleaning. This is the worst part. Finding that sweet spot your engine likes.
Your plug could still be on the cold side.
What sparkplug is used? Maybe step up a few heat ranges?
You gotta find that afr area where the plugs are self cleaning. This is the worst part. Finding that sweet spot your engine likes.
Your plug could still be on the cold side.
What sparkplug is used? Maybe step up a few heat ranges?
OP
OP
ttocs
Post Whore
Target afr up till 900 rmps is 13.9
I believe they are autolight 23s with .35 gap but don't quote me or curse me for using them.
I dont remember what head you are running and im sure you are using recommended type plug or of the similar. Meaning the plug protruding to far into the chamber or not protruding enough, down inside the plug hole. Down in the hole with definitely cause black plugs. Do you remember sparkplug protrusion on the chamber side? Hopefully its correct and flush
Dont be affraid of 16.1 afr around idle. Hell, newer cars are under loads driving with 16.1 now a days thanks to multi spray pattern direct injection.
Now once you finally make it tuning in the upper rpms, 16.1 is gonna heat things up a bit.
The cooling system and fuel air mix keeps temps at bay at the bottom rpm and the valves have no problem staying cool especially with aluminum heads.
Dont be affraid of 16.1 afr around idle. Hell, newer cars are under loads driving with 16.1 now a days thanks to multi spray pattern direct injection.
Now once you finally make it tuning in the upper rpms, 16.1 is gonna heat things up a bit.
The cooling system and fuel air mix keeps temps at bay at the bottom rpm and the valves have no problem staying cool especially with aluminum heads.
OP
OP
ttocs
Post Whore
I would not make the assumption that I got good info necessarily as I do not know what I should to have done all this. Someone somewhere recommended those plugs but I can't tell you who. Not sure how to check protrusion...
Well....the manufacturer should have plug suggestions. Or at least style type
OP
OP
ttocs
Post Whore
well its so important you had to quote yourself? 
trickflow recommends
AC FR3LS
Autolite 3924
Champion RC9YC
NGK FR5
it seems like the searches I do lead mostly to the autolite or ngk being used.
trickflow recommends
AC FR3LS
Autolite 3924
Champion RC9YC
NGK FR5
it seems like the searches I do lead mostly to the autolite or ngk being used.
01yellercobra
Active Member
- Joined
- Feb 23, 2018
- Messages
- 628
- Reaction score
- 193
I've run NGK's in multiple boosted set ups with good results. After having a set of Autolites fall apart on me and a friend I switched to the NGK's.
Thats really rich for idle. As said lean it out to stoic at least. Granted mine is a mod motor, but it idles around 14.7 and cruises a tad leaner than that.
Thats really rich for idle. As said lean it out to stoic at least. Granted mine is a mod motor, but it idles around 14.7 and cruises a tad leaner than that.
Last edited:
OP
OP
ttocs
Post Whore
I think I will try the ngk's this time after hearing them mentioned a few times. I am am going to hold off on making any tuning adjustments until I do get it on the road a little more, or at all really... I have been fighting with getting the front end aligned enough to get it to the shop to get it fully aligned but after more then a few tries I might just have it towed in.
joe65
Well-Known Member
- Joined
- Feb 4, 2020
- Messages
- 1,478
- Reaction score
- 1,444
you might have seen this. The autolites aren't typically known to be bad?? I've used ngk on my audis and really liked them.
http://www.efidynotuning.com/pre.htm
Pushrod SBF TFS Twisted Wedge 302 5.0 Autolite APP 3923 - 0.032"
that's his rec. for a boosted pushrod with twisted wedge heads.
http://www.efidynotuning.com/pre.htm
Pushrod SBF TFS Twisted Wedge 302 5.0 Autolite APP 3923 - 0.032"
that's his rec. for a boosted pushrod with twisted wedge heads.
OP
OP
ttocs
Post Whore
I am not saying they are bad I am sure its something I have done/am doing to it. I just was not sure if there was not something better I am sure like we all do. I had been gapping them at .035 so I will try .032 this time and see if it helps. If not I can go back to .035. Its nice to see some data for the first time really as it seems that most of this is locked up in peoples heads.
01yellercobra
Active Member
- Joined
- Feb 23, 2018
- Messages
- 628
- Reaction score
- 193
Just remember generally a tighter gap can lead to idle and part throttle issues. I don't see you having an issue at .032" or .035". But just don't go crazy.
I still say lean out the idle about a point and see how it acts.
I still say lean out the idle about a point and see how it acts.
95opal
Well-Known Member
- Joined
- Jun 21, 2007
- Messages
- 3,028
- Reaction score
- 1,612
/\ this but i would lean out the idle first.
Not sure how i quoted my post...weird!well its so important you had to quote yourself?
trickflow recommends
AC FR3LS
Autolite 3924
Champion RC9YC
NGK FR5
it seems like the searches I do lead mostly to the autolite or ngk being used.
Anyhow, yes the ford related sparkplugs have gone to crap. NGK are my pick as well. When you build crazy crap like 18:1 compression engines, you find the differences in sparkplug quality and NGK rank high in consistency.
Last edited:
