spark blow out problems
spark blow out problems Lq4 with a t7875 on 21psi
Btr dual springs and hardened push rods
3 bar with alky control 100% methanol
Br7ef gapped to .018 brand new plugs
Afr 11.3 to 11.5 wot
Heat sink coils with stock wires
Can't get rid of the blow out at high rpm (5900 or so) , thought about trying ngk 1049 (8 heat range) and new wires , just trying to see if there is anything else I'm overlooking , car runs great in any other condition , on 18 to 19psi it doesn't do it , did a log today and only thing abnormal was kr was pulling 1 to 2 degrees out when I was experiencing blow out .... any help is appreciated
Btr dual springs and hardened push rods
3 bar with alky control 100% methanol
Br7ef gapped to .018 brand new plugs
Afr 11.3 to 11.5 wot
Heat sink coils with stock wires
Can't get rid of the blow out at high rpm (5900 or so) , thought about trying ngk 1049 (8 heat range) and new wires , just trying to see if there is anything else I'm overlooking , car runs great in any other condition , on 18 to 19psi it doesn't do it , did a log today and only thing abnormal was kr was pulling 1 to 2 degrees out when I was experiencing blow out .... any help is appreciated
It's on a stock ecu in a 99 trans am , no I haven't messed with anything to do with the coils just swapped them in case the old ones were the problem since I had the truck coils laying around
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Wow, this sounds like the same damn thing I'm dealing with.
21-22psi, .018 gap on ngk 1049s. Even got the random knock he said. E85, 15.5-16.5 timing. 180 eng temps, and AITs below 120.
5.7L 9.5 compression S480/92 1.0 t4
I was wondering if it's 112k OEM truck coils are tired. Thinking about trying those 15% hotter Accel coils. Wish hey wasn't yellow, they ugggly.
How tight can you go?
21-22psi, .018 gap on ngk 1049s. Even got the random knock he said. E85, 15.5-16.5 timing. 180 eng temps, and AITs below 120.
5.7L 9.5 compression S480/92 1.0 t4
I was wondering if it's 112k OEM truck coils are tired. Thinking about trying those 15% hotter Accel coils. Wish hey wasn't yellow, they ugggly.
How tight can you go?
I'm running a walbro 450 and a stock pump as my second pump , I have a brfpr and 60# injectors plus 100 percent methanol , the car made 780rwhp and 811rwtq and I can drown the motor with methanol if I turn it up lol so I don't think it's fuel , plus the afr is good every single time it does it , maybe it is something else but it stutters or sounds like fast gurgling at high rpms and it's not constant ,it'll go in and out really fast sometimes and sometimes it will do it worse .... I'm just out of ideas
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Joined: Mar 2014
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From: Ohio
This same thing just started to happen to me after turning the boost back up to where it was last year. I changed to a TBSS intake/90mm TB over the winter and rebuilt the hotside to flow better (more gradual bends).
At 10 PSI I was fine. Even had to add 20% fuel over last year.
Now at 21-24 PSI, I get lots of what sounds like misfiring at 5000+ RPM.
I did change a couple of plug wires because I needed the longer ones I was using on another build, and went with a larger water/meth nozzle (I run 70% water/30% meth). I also added a brake booster. It seems like I might've either screwed up a ground wire somewhere or possibly picked up a boost leak since most of the cold side/intake has changed.
I run the same plugs as you with a much wider gap (.028) and didn't have this problem last year. Same coils, same AFR.
At 10 PSI I was fine. Even had to add 20% fuel over last year.
Now at 21-24 PSI, I get lots of what sounds like misfiring at 5000+ RPM.
I did change a couple of plug wires because I needed the longer ones I was using on another build, and went with a larger water/meth nozzle (I run 70% water/30% meth). I also added a brake booster. It seems like I might've either screwed up a ground wire somewhere or possibly picked up a boost leak since most of the cold side/intake has changed.
I run the same plugs as you with a much wider gap (.028) and didn't have this problem last year. Same coils, same AFR.
I don't follow the first part , maybe I'm reading it wrong , but I'll throw another wideband in it and double check the afr