Low timing in high rpms

[slow2o]

A little backround information, my car os a 90 gsx with pte 50 trim, 550cc injectors, fpr set to base 43psi, web street grind cams(similar to 272s), 2g maf and jmf intake manifold. m tuning with safc and watching my logger with mmc.

Now onto the problem, when i do a wot pull im getting good timing pre boost but once i hit boost it just starts a steady sweep downhill to about 10* where it seems tyo level out. I have been trying to figure this out but am stuck i have boost leak tested the car numerous times and all come up good.

The logs seem to look pretty good besides dropping timing and my fuel trims are all at about 100% give or take 2% which is ok according to my research. Any thoghts because im running out of ideas.

Thanks Brian

 

[PandaMan]

What are your intake temps? Are you on premium fuel or e85?

 

[slow2o]

93 octane and the air temps are at between 37 and 46*c and looking back through the logs something that stood out was the hz over 1000 at any high throttle pull and up around redling its reading 1599 which seems to be the max flow by how it just peggs this number.