You have to remember every 1psi of pressure raises ambient temperatures about 10deg. So 10lbs of boost = 100deg + Initial temp which would put it about 180deg in the summer
Wherever you got that information at is WRONG. 1psi of pressure is definately more than 10 degrees. An Intercooler will lower temps 100 degrees or more, it has been proven many times with temps taken after the blower before the Intercooler and after the intercooler. If the intercooler lowers temps 100 degrees and 1psi=10 degrees then I can run an extra 10psi, but unfortunately that is not the case, if it was the case then our GTP would run low 12'*. In the GTP we run about an extra 4-5psi more than what we did before the IC, any more than that and we see KR. So your number, wherever you got it from, is at most 1/2 of the real temperature. Calculated my way I would say that 10psi + 80 degrees would be at least 280 degrees, and that is a guess based on my observation, I have no proof to back it up other than Autotap logs.
1990 Maroon Grand Prix STE McLaren 3.1 Intercooled Turbo, 14.695 @ 94.49 on 12psi before cam/heads/etc.
1990 Bright Red Grand Prix McLaren 3.1 Intercooled Turbo, 14.819 @ 92.72, 189whp
1999 Grand Prix GT 9.75:1|K&N|160 tstat|No Ubend/Cat/Res|UD Pulleys|Ported M90/TB/Heads|XPZ|2.55"|Pacesetters|Stage 2 I/C. 12.442 @ 112.78
2000 Blue Bonneville SSEi Supercharged Gutted Airbox|K&N|3.4"|1.9'*|WP Pulley|Custom DHP|180*stat|41932'*|No Cat. 14.681 @ 94.80
2002 Dark Cherry Grand Prix GTP Supercharged & Intercooled
12.084 @ 114.38 w/1.743 60', 315.6whp, Fastest Stock Cam M90 GTP!
NOW XP CAMMED, 340.6whp with XP, stock heads, Gen 3 M90, 11.984 @ 115.84 w/1.750 60'!
Most HP Stock Heads Gen 3 M90 GTP!
2004 Red Monte SS Supercharged K&N|3.4 Pulley|1.9'*|180*stat|41919 plugs|3" dp|No cat/ubend|DHP|Shift Kit. 14.2 @ 98
GOT BOOST??? Friends dont let friends drive stock!