.16 spark plug gap, still getting blowout. Bad coils?
#1
Newbie
Thread Starter
.16 spark plug gap, still getting blowout. Bad coils?
Hey all, I just recently got my 8 tuned on E85 with a target boost of 27 lbs. Made 432/399 on the dyno.
It ran fine on the way home, drove it today and I'm getting spark blowout at wot towards 6500k rpms. Stock block, tdo5/20g turbo. 272 cams, Ams 3.5 Fmic, short route licp, stock route uicp, stock ignition.
It's currently got br8eix plugs in it gapped at.16.
It had bpr7eix plugs in it when it was on 93 and I never had blowout.
Am I using too cold of a plug? It idles/cruises fine and runs fine in lower boost but wide open throttle towards 7k I get lots of misfire in all gears.
Any suggestions?
It ran fine on the way home, drove it today and I'm getting spark blowout at wot towards 6500k rpms. Stock block, tdo5/20g turbo. 272 cams, Ams 3.5 Fmic, short route licp, stock route uicp, stock ignition.
It's currently got br8eix plugs in it gapped at.16.
It had bpr7eix plugs in it when it was on 93 and I never had blowout.
Am I using too cold of a plug? It idles/cruises fine and runs fine in lower boost but wide open throttle towards 7k I get lots of misfire in all gears.
Any suggestions?
#2
Evolved Member
iTrader: (4)
Hey all, I just recently got my 8 tuned on E85 with a target boost of 27 lbs. Made 432/399 on the dyno.
It ran fine on the way home, drove it today and I'm getting spark blowout at wot towards 6500k rpms. Stock block, tdo5/20g turbo. 272 cams, Ams 3.5 Fmic, short route licp, stock route uicp, stock ignition.
It's currently got br8eix plugs in it gapped at.16.
It had bpr7eix plugs in it when it was on 93 and I never had blowout.
Am I using too cold of a plug? It idles/cruises fine and runs fine in lower boost but wide open throttle towards 7k I get lots of misfire in all gears.
Any suggestions?
It ran fine on the way home, drove it today and I'm getting spark blowout at wot towards 6500k rpms. Stock block, tdo5/20g turbo. 272 cams, Ams 3.5 Fmic, short route licp, stock route uicp, stock ignition.
It's currently got br8eix plugs in it gapped at.16.
It had bpr7eix plugs in it when it was on 93 and I never had blowout.
Am I using too cold of a plug? It idles/cruises fine and runs fine in lower boost but wide open throttle towards 7k I get lots of misfire in all gears.
Any suggestions?
#3
Newbie
Thread Starter
The 8 plugs are brand new,(installed Thursday night, got tuned for E85 Friday) the 7s had roughly 20k miles on them.
#5
Newbie
Thread Starter
Pretty sure it's not the tune as it had no issue on the dyno or on the way home, or the day after. Only today as I drove it did it start. The plugs were gapped at 18,i gapped them down to 16 with no change.
#7
Account Disabled
You mean it's got a misfire?
No such thing as "blowout".
AFR will be too rich.
Photos of plugs required.
You've probably done what everyone else does and cocked up the fuel pressure.
No such thing as "blowout".
AFR will be too rich.
Photos of plugs required.
You've probably done what everyone else does and cocked up the fuel pressure.
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#8
Newbie
Thread Starter
And if there's no such thing as blowout, I should be able to run stock plugs gapped at .032 at my boost levels then? I mean, if afr's are good the cylinder should fire, regardless of cylinder pressure?
Last edited by wisewendell; Mar 13, 2018 at 02:26 AM.
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ctfpevoVIII (Mar 13, 2018)
#12
Newbie
Thread Starter
Hopefully going to the bpr7 and the COP fixes it.
#13
Evolved Member
Spark flame does not blowout. What happens is, the spark makes the jump a little too late, due to various reasons such as the wrong plug, a worn plug, a worn/weak coil, too rich of a mixture, too lean of a mixture overheating the plug, or if it jumps on time it is too weak, or both.
At the boost pressure and density of mixture you are running there is no need for an ngk 8 plug. The 7 heat range is more than ok, even if you were on pump gas. The comment about the e85 burning cooler is correct. Thus in your case or any same one, two things happen, there is carbon build up within the spark plug due to a rich e-85 mixture which burns on the coldest side of things thus not allowing the spark plug to reach optimum functioning temperature and remain there and or you also have a weak coil which enhances the carbon build up and it does not charge the plug properly for it to fire as it should.
Get a new set of coils before you change the plugs, see how much it improves the problem, do not go to the 7 heat range plugs, keep the 8s, otherwise if problems still is at some degree, change the plugs also to 7s and you should be ok if there is no other electrical/ecu malfunction.
Marios
At the boost pressure and density of mixture you are running there is no need for an ngk 8 plug. The 7 heat range is more than ok, even if you were on pump gas. The comment about the e85 burning cooler is correct. Thus in your case or any same one, two things happen, there is carbon build up within the spark plug due to a rich e-85 mixture which burns on the coldest side of things thus not allowing the spark plug to reach optimum functioning temperature and remain there and or you also have a weak coil which enhances the carbon build up and it does not charge the plug properly for it to fire as it should.
Get a new set of coils before you change the plugs, see how much it improves the problem, do not go to the 7 heat range plugs, keep the 8s, otherwise if problems still is at some degree, change the plugs also to 7s and you should be ok if there is no other electrical/ecu malfunction.
Marios
Last edited by Evo8cy; Mar 13, 2018 at 11:59 AM.
#14
Newbie
Thread Starter
Spark flame does not blowout. What happens is, the spark makes the jump a little too late, due to various reasons such as the wrong plug, a worn plug, a worn/weak coil, too rich of a mixture, too lean of a mixture overheating the plug, or if it jumps on time it is too weak, or both.
At the boost pressure and density of mixture you are running there is no need for an ngk 8 plug. The 7 heat range is more than ok, even if you were on pump gas. The comment about the e85 burning cooler is correct. Thus in your case or any same one, two things happen, there is carbon build up within the spark plug due to a rich e-85 mixture which burns on the coldest side of things thus not allowing the spark plug to reach optimum functioning temperature and remain there and or you also have a weak coil which enhances the carbon build up and it does not charge the plug properly for it to fire as it should.
Get a new set of coils before you change the plugs, see how much it improves the problem, do not go to the 7 heat range plugs, keep the 8s, otherwise if problems still is at some degree, change the plugs also to 7s and you should be ok if there is no other electrical/ecu malfunction.
Marios
At the boost pressure and density of mixture you are running there is no need for an ngk 8 plug. The 7 heat range is more than ok, even if you were on pump gas. The comment about the e85 burning cooler is correct. Thus in your case or any same one, two things happen, there is carbon build up within the spark plug due to a rich e-85 mixture which burns on the coldest side of things thus not allowing the spark plug to reach optimum functioning temperature and remain there and or you also have a weak coil which enhances the carbon build up and it does not charge the plug properly for it to fire as it should.
Get a new set of coils before you change the plugs, see how much it improves the problem, do not go to the 7 heat range plugs, keep the 8s, otherwise if problems still is at some degree, change the plugs also to 7s and you should be ok if there is no other electrical/ecu malfunction.
Marios
Last edited by wisewendell; Mar 13, 2018 at 01:25 PM.