Over 1k hp tunning help

[wickedcummins]

setup is a 408 with TFS 220s. fuel is e98. ngk7s gapped at 21. 2004 coils with MSD wires Twin turbos flowing 198lbs/min. When trying to go over 13psi it feels like I am blowing out spark but dyno does not reflect it.

[wickedcummins]

Been reading a little and some talk about changing dwell times on the coils. Do I need to mess with this at all ?18823

[turbo_bu]

are you running the truck coils? There are quite a few guys running stock coils over 1000 HP.

[wickedcummins]

are you running the truck coils? There are quite a few guys running stock coils over 1000 HP.

Yes I have 04 truck coils that had 88k on them. researched that also and made sure I had the best stock option... Is there a better aftermarket COP coil ?

[joecar]

Been reading a little and some talk about changing dwell times on the coils. Do I need to mess with this at all ?18823What is causing AFR to start going up from 135 mph...? Are you postulating that air/fuel mixture is not igniting (spark been blown out)...?

[joecar]

The truck coils with the finned heat sink are good (aftermarket coil(s) are not as good and may suffer quality issues)... did you copy the dwell table for those coils...?


What spark plugs...?
What is spark plug gap set to...?

[joecar]

Shouldn't dyno power curve keep rising at that point (if AFR was steady and spark was not getting snuffed)...?

What does dyno torque curve look like...?

[joecar]

Do you have any tool for monitoring secondary voltage...?

an oscilloscope waveform of secondary voltage will show if ignition occurs and progresses to completion (waveform will have specific shapes for good and misfire cases);

a xenon tube spark tester shows if there was a current pulse (altho this may not be a good indicator);


( basically, how do we view inside combustion chamber )

[wickedcummins]

thanks for the response joe.. I have not changed any dwell tables. I have the square truck coils with out heat sinks on it i read some where the heat sink coils are weaker. I do have a set of them off a 99 I could use if you think they are stronger.

I have a custom OS and file loaded in the truck. ECU was originally a big block 8.1. Needs this ecu as it has the chip for IAC and not DBW.

Plugs are (3346) BR7EF.. Started at 28 now down to 21
+

[wickedcummins]

Getting file with torque as I type this.. Do you think I should use the heat sink coils? Or in your opinion what is the best ls1 coil to run ?

[wickedcummins]

Do you have any tool for monitoring secondary voltage...?

an oscilloscope waveform of secondary voltage will show if ignition occurs and progresses to completion (waveform will have specific shapes for good and misfire cases);

a xenon tube spark tester shows if there was a current pulse (altho this may not be a good indicator);


( basically, how do we view inside combustion chamber )

I used to have a snap on scope but not anymore.

[wickedcummins]

1882418824

[wickedcummins]

18825

[joecar]

thanks for the response joe.. I have not changed any dwell tables. I have the square truck coils with out heat sinks on it i read some where the heat sink coils are weaker. I do have a set of them off a 99 I could use if you think they are stronger.

I have a custom OS and file loaded in the truck. ECU was originally a big block 8.1. Needs this ecu as it has the chip for IAC and not DBW.

Plugs are (3346) BR7EF.. Started at 28 now down to 21
+


Getting file with torque as I type this.. Do you think I should use the heat sink coils? Or in your opinion what is the best ls1 coil to run ?


I'm not sure which are stronger... use the coils you think are better, and use the dwell table that goes with them.

You can try increasing dwell say 10-15% and see what happens.

Hmmm, plug gap is getting narrow.

[wickedcummins]

I'm not sure which are stronger... use the coils you think are better, and use the dwell table that goes with them.

You can try increasing dwell say 10-15% and see what happens.

Hmmm, plug gap is getting narrow.

My thoughts also. I dont wanna drop much more.. 18 is the lowest I feel comfortable with.. Im just not sure Im not missing some kind of weird limit table