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Originally Posted by speedyman
^^^^^I see exactly what you are pointing out. The obvious question is why. Thank you very much for the help with reading and understanding the data.
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Timing pulls from the DME occur because it detects knock and this is a safety reaction. Beyond the safety, timing drops equal horsepower drops. Generally knock will occur if IAT get too hot or back pressure causes high combustion temps. I am pretty sure he can log IAT off the JB4. That said, I am willing to bet the stock downpipes are a big, big contributor. If he logs after he installs the pipes, we can safely assume that was a big part of the problem.
Either way, we can 100% tell if that timing drop was knock by increasing the octane with a few gallons of MS109 or running a few gallons of ethanol. The higher octane is more resistant to knock, so we would be sure. My guess is that 22 psi is too much with an otherwise stock vehicle. You may need downpipes to run that much boost.