Cutting out high rpm (video inside)

[sunshine-ga]

Having a little issue.

The car starts breaking up around 6k rpm. AFR still looks solid at around mid 11’s (it did dip into 10’s one pull however)

There are no misfire codes

Any ideas what the issue might be here?


98 cobra. T56 swap. 70mm turbo. Running 7.5-8psi this pull.

car was tuned for this exact setup (before engine blew). Only difference is it was tuned for 11 psi. Same rods in it same compression

About 500 miles on new motor.

 

[98 svt]

Any background on the car?
What year?
Mods?
Is there a tune on it?
Have you done anything to the car recently?

 

[sunshine-ga]

Updated. Sorry should have posted this earlier.

 

[CobraBob]

Almost imperceptible. I thought it was dropping revs when you shifted.

 

[BOTTLEFED5]

What are the plugs gapped at? seems like spark blowout.

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[CobraBob]

Yeah, that is possible. Definitely check the plug gap for too-wide a gap.

 

[sunshine-ga]

What are the plugs gapped at? seems like spark blowout.

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This was the issue. They were gapped at .032

pulled the gap down to .028 and all seems good again.
Crazy that small of a gap will make a difference.


Thanks everyone

 

[BOTTLEFED5]

This was the issue. They were gapped at .032

pulled the gap down to .028 and all seems good again.
Crazy that small of a gap will make a difference.


Thanks everyone

Yea, on my old b head motor i had to gap em down to .022 crazy how much it makes a difference

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