Originally posted by monkey
i've seen enough threads (1 or 2) about guys hydrolocking in heavy rain. who knows what their wheel wells were like, or what they did to their cars, but it's enough of a risk and not enough of a reward to warrant getting a CAI. Type S airbox or Short Ram + Cold Air box might be safer for those living in wet places.
Bypass valves costing you 1 HP leaves a net gain of around 1.2 HP to the wheels. :P we talking 1hp at the crank or the wheels?
and about dyno testing with open or closed hoods and the short ram: the ambient air temperature inside of the engine compartment at speed has been shown to be pretty much the same as the temperature outside. The airflow into the engine bay and the movement of air insures that the short ram pulls cold-ish air (depending on the weather). The only problem is when accelerating from a stop, when the air in the engine bay has been stagnant for a few and has heated up. I haven't done my own tests because i'm not sure i care that much, but a friend of mine who worked at DC said that told me this.
i have an AEM CAI. i like it. Don't think i'd want anything else at this point.
ok.....heat rises...that's why vents are put in the hood.....i've done my own tests with this sort of thing on turbocharged cars....one was a stock 94 rx7, a 95 mustang gt, and an 85 xr4ti......on the rx7, the intake is on the same side as the turbos.....with an infrared gun, the plastic box part of the stock intake would hit around 225 degrees under normal driving during 85degree or similar weather.....a short ram would be drawing the air in at that temp......with the hood up on a dyno, still 100% stock, the box only registered 170 degrees........that's 55 degrees difference, which is what the short ram would experience therefore giving it a 5% higher reading on the dyno numbers....so you're getting a dyno that says the car is making 5% more hp than it really is while you're driving....a big deal.....on the mustang with a few mods, it was only about a 30 degree difference, but still, 3% of it's power....3% of 225hp is almost 7whp.....a very real difference.....on the xr4ti, it was the worst though....it's known for a super hot engine compartment.....the intake box hit around 250 degrees....cutting the sides off to allow it to draw in air from the engine comparment wouldn't make a difference with the hood up....we ran it with the hood down and the fans blowing on the front like it would be going down the road and with the box open, it would experience detonation and lost 15hp from 2500rpm to 6200rpm........some of the loss was due to the knock sensor killing the timing, but that's because air coming in was too hot.....most of the time, the restriction on n/a cars is worse than the heat you'll be getting, so either makes power...on turbo cars, it's usually not.......10 degrees = 1% of your total hp
and the bypass valve kills 1hp to the wheels from what i've seen...sometimes not 1 full hp.......