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The dreaded Breakup/ Misfire under boost..[RESOLVED]

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My car somehow has developed a misfire/Breakup/Sputter whatever you wanna call it under boost only, It drives and runs perfect until you go WOT and the turbos come online then she goes nowhere no power just break up... Throwing no Codes but can see misfire in the log.

Things I've done:
_____________
New Plugs (NGK 6510s @ .028)
Verified/ Disconnected MSD
Inspected coil pack boots
Verified all vacuum lines/ Couplers look good
Known Good tune/ Flashed another known tune and no change

Update!: FIXED, NEW PLUGS HAD CRACKS IN THE PORCELAIN!!!~~~~
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Tommy V

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If u verified all of that u might wamt to do a compression test,or do a log of the misfire and see if you.are getting detonation.Also check your maf sensor to make sure its clean.Is the misfire always the same cylinder?
 
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If u verified all of that u might wamt to do a compression test,or do a log of the misfire and see if you.are getting detonation.Also check your maf sensor to make sure its clean.
At first it was detonating but after I changed the plugs no knock..
 

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Is the same cylinder always have the misfire.
 
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Is the same cylinder always have the misfire.
Not sure which one/s are doing it but it hasn't thrown a single code yet..
 

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Tommy V

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If its only under load it sounds like its igition related.If u have acess to.a scan tool u can monitor misfires and see which cyl is misfiring even though its not setting a cel.Also might want to.clean your maf sensor.
 
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If its only under load it sounds like its igition related.If u have acess to.a scan tool u can monitor misfires and see which cyl is misfiring even though its not setting a cel.Also might want to.clean your maf sensor.
Going to hook up a scan tool... Just waiting on it to stop raining!
 

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You sure a charge pipe didn't come loose? A car will run ok until you get under boost and it doesn't have the air it was expecting..
 
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You sure a charge pipe didn't come loose? A car will run ok until you get under boost and it doesn't have the air it was expecting..
All couplers are good
 

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I had been running 17psi of boost with my Whipple previously and the car ran perfect.

Now I'm seeing the same thing with my newly added Boostworks kit with Comp 6062's. Any boost over 10psi or so will cause terrible misfiring. I've seen different cylinders throw a code but I'm seeing P0300 the most for random misfire.

Lund and Boostworks told me I needed to run stronger valvesprings so I switched to the recommended Livernois ones that Boostworks said to run. I'm still seeing practically the same misifiring over 10-12psi of Boost. My 6510 plugs are also gapped at .028".

Lund says they can see in my logs that the exhaust cam is losing control yet due to valve float even with the new springs and I need to reduce exhaust backpressure. I'm trying to order the upgraded Boostworks headers to replace my modified stock headers now.

I'm in the same boat as you. Does the Hellion kit have custom good flowing headers?
 

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there is a difference between misfire and breakup.

if it's breaking up, i would double check the plug gap,
 

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I had been running 17psi of boost with my Whipple previously and the car ran perfect.

Now I'm seeing the same thing with my newly added Boostworks kit with Comp 6062's. Any boost over 10psi or so will cause terrible misfiring. I've seen different cylinders throw a code but I'm seeing P0300 the most for random misfire.

Lund and Boostworks told me I needed to run stronger valvesprings so I switched to the recommended Livernois ones that Boostworks said to run. I'm still seeing practically the same misifiring over 10-12psi of Boost. My 6510 plugs are also gapped at .028".

Lund says they can see in my logs that the exhaust cam is losing control yet due to valve float even with the new springs and I need to reduce exhaust backpressure. I'm trying to order the upgraded Boostworks headers to replace my modified stock headers now.

I'm in the same boat as you. Does the Hellion kit have custom good flowing headers?
Nope hellion uses stock manifolds and I’m running 15-16psi on 3 year old stock valve springs and have run 8’s. I doubt the header will change anything if you are having trouble at only 10psi. I would do a bigger exhaust side on the turbo and dump your exhaust right after the turbo’s to the ground.
 

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Nope hellion uses stock manifolds and I’m running 15-16psi on 3 year old stock valve springs and have run 8’s. I doubt the header will change anything if you are having trouble at only 10psi. I would do a bigger exhaust side on the turbo and dump your exhaust right after the turbo’s to the ground.
Hmmm that is odd. Initially before I tied in my cat back system I tried to run it at 15psi with only 18" long pipes off the turbos that were open under the car and it still misfired just the same. My turbos are the Comp 6062's that were in the kit with a .82 A/R turbine side. What size turbos are you running and what is the A/R?

I wanna run 8's!!! :rant::rant:
 

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Hmmm that is odd. Initially before I tied in my cat back system I tried to run it at 15psi with only 18" long pipes off the turbos that were open under the car and it still misfired just the same. My turbos are the Comp 6062's that were in the kit with a .82 A/R turbine side. What size turbos are you running and what is the A/R?

I wanna run 8's!!! :rant::rant:
Hmm, I have precision 6266’s with .82 AR also.
 
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Going to attempt to rule out the coil packs today, the only things I can think of is a clogged injector/bad BAP or failing fuel pump or the intake manifold runner shaft being broken and messing up airflow to one bank.... but it's so weird the car runs perfect until WOT... pretty frustrating
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