150W HPS vs 250W HPS temps and penetration

I WANNA UPGRADE TO A 250W BUT I HAVE SOME INFO/ QUESTIONS FOR THE COMMUNITY FIRST:

I currently have a 150w hps in a diy cooltube with a 50cfm exaust fan blowin on her(through cooltube) in a steralite 2 shelf cab and the dimensions are (25 5/8" L x 18 7/8" W x 35 5/8" H ) basically 2'X1.5'' with another 150 angled in a floodlight flector in the top corner for even distribution on at random intervals. also in/along the bottom right there is another powerstrip with 4 26w cfl also on intermittenly for side lighting in the dimmer area less covered by cooltube.. both on at opposite times for only about an hour every 2 hours or so to keep heat down because it goes into mid 80's (cfl) and to the lower 90's (extra non aircooled hps) with doors closed. The temps stay about 75-77 with just cooltube , i want to upgrade to a 250w for better coverage and penetration but don't know much about the actual temp difference between them.This little 50cfm seems efficient at cooling the 150, no sweat, but would it be enough for a 250 as i may not have enough to upgrade the fan, and just got it? Being able to somewhat handle the supplemental extras, im wondering if that will help with the understanding of the temperature increased...?

Any ones input on upgrading from 150 to 250 is welcome... anything at all.

 

thanks! ive seen that chart before, but its badass to have right here thanks! so you think the temps wouldnt be that much hotter? i wanna be able to squeeze 4zipperdoodles outta that small box, i think i could with a 250 n a few cfl.

 

anyone?