Hi,Oldhead here,Theres 20" of snow here in Philadelphia and not much to do when your 74 years old , When my wife finishes shovling the walkway I might have bouncey bouncey but in the mean time I can read.So I get out my old dyno sheets.I have over a hundred and fifty pulls in the past 15 years on my present SBC-400. I have had 5 different blower(B&M 144,162,250 and a 871) and present a Vortech YSI,I ran nitrous with all of them also...........I notice things that I did not pay much interest in before. I want to talk about bonnet temperature.I know the colder the better,but when is it too hot.I mean Dangerous.I have no intercooler other then my Snow W/A injector(W/A inj).At the dyno with 14# of boost and no W/A i see 217 degs.,809 HP with the timing WAY down.With 1 (625) nozzle I see 150 degs,800 HP(Lost 9). At 22# of boost and valve float see with no W/A inj. 270 degs,1 nozzle 145 degs,lost ,2 nozzles,135, with 26# of boost no W/A 295,1 nozzle 175,2 nozzles 155........................................WOW.......................................I know some of these temps are outrageous,but I have many pulls and 1/4 mle runs with the 22# boost level using NO W/A and have used nitrous too (1130 hp).To remind you this is BONNET presure and a blowthru gets cooling below the carb.I should have tested below the carb but the sensor would not fit.I also have to big a nozzle because the more nozzles I use the more power I lose even though the temp drop over a 125 degs................(Right after the pulls I replaced the valve springs)..Even with these temp the car runs good. HERES the question again "how hot is to hot"OLDHEAD PS: I have ordered smaller nozzles

 

I'd say too hot is when it starts to ping. But if you knock 125 deg out of the intake temp, add 105 octane and don't compensate, expect to loose HP. A bump in a deg or two probably would have seen good gains with temp drops like that.