Better late then never right? Through the years I've changed out my valves springs a few times for duals (dual golds right now with TIT retainers), this dyno graph was on singles (this was when ls1's were still fairly new) The shop at the time also said my injectors were not running at 100% and were likely not the issue (mistake?).

I also replaced my rockers with new ones (stock). The issue still follows me to this day. Have you ever seen anything like this where the power just goes almost straight down? I am working on gathering parts to get a proper dyno tune but was wondering if this could be a problem with the setup of the motor. I don't want to spend lots of $$$ on a tune to be told you need to pull the motor apart (worried its the lifters).

Btw the car was somewhat de-tuned since and dynoes 400-410 now. Also has 100k miles.
Thank you for any info you can provide.

 

Maybe a weak pump? Any voltage issues?

 

The pump was replaced once by the dealership under warranty. Having said that the car has been dynoed 5 other times and it always acts up at the same RPM. Now that I think about it that would have to be a tuning issue wouldn't it? If it was the motor it would not likely always happen at the same RPM.

 

It could also be not enough injector for the power your making, though if mods in the pics are accurate the dyno seems to be alittle happy. But if accurate stock injectors seem to max out anywhere from 420-450.

 

What is your exhaust setup like?

 

Mac mids. Tried open headers and same thing.