06/03/2026
Saw a post earlier and thought it would be a good topic to post about. Someone noticed 797 Performance is now advising that a larger set of injectors would be beneficial for the Killer Bee camshaft.
Here is a Dyno run of a 6.4 with a Killer Bee camshaft. As you can see, at 6400 rpms, the stock 6.4 injectors are at almost 90% duty cycle, which is about the cut off of “safe” limits. This is honestly fairly common with all of the more aggressive camshafts offered for the 6.4.
Now, if peak power was being made at ~6100 rpm, it wouldn’t be much of a concern. We could set shift points at 6400 and the customer would be good to go. However, the Killer Bee camshaft & many others, carry peak HP to 6300-6500 rpm, so for the customer to see the maximum potential of their setup, ideal shifts would need to be around 6700-6800 rpm, which would put the stock 6.4 injector duty cycle near or past 100% which is VERY dangerous.
So yes, if you want MAXIMUM results, going with a set of larger injectors would indeed be advised. If you’re ok with leaving a few hundred rpm on the table, then you can get away with the stock injectors.
