RAM AIR

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And all that crap.

From Mitsuclub by FLiPMaRC's post.

http://www.vetteguru.com/ramair/

So next time anybody tell you the ram air on their car works, tell them it's crap.

It'll work only at very high speeds(above 120mph iirc) with a very good design & even then there's only a 1psi increase.

[ghosthunter]

so its only as good as a cold air intake?

[yebo]

cai naman talaga function ng air scoop sa hood. anyone who tells you it increases air intake pressures must be loco. it's still the same 14.7 psi atmospheric. the name ram air is a misnomer imho.

if one bothers to do a dynamic pressure analysis, on paper, on the ram air, then it becomes very obvious that it will not raise the pressure in the intake manifold to any degree. 14.7 psi at entrance of ram air can not suddenly become more than that value inside the "ram" without any energy input. the only thing that can build up pressure is the pressure wave in front of the ram, but this is minimal at speeds that land vehicles normally travel. so the claim that it works like a turbo can not be substantiated even on paper.

what it actually does is to facilitate the entry of cool air into the air box, acting as a cai on the hood. also (and this may just be the reason behind the claim) it allows more air to enter due to dynamic pressure and thus there will be no vacuum at the inlet. dynamic pressure can't be measured by conventional pressure gauges, you need a venturi or pitot tube (as in airplanes) to measure that.

in other words, look at it as like an air hose directed at the air scoop with the vehicle at a standstill. the air may be travelling at 100kph toward the scoop but if you measure this pressure just inside the air scoop then it is the same atmospheric pressure air. but then again there is no vacuum pressure inside the inlet manifold, which of course suggest that it works.

so what am i saying, ang gulo ano? simply, it does not work as a turbo, so you can't measure it's pressure effect like you would a turbo. if you do then it's like comparing apples and oranges. but it works in other ways, as a cai and that damn dynamic air pressure (as compared to static air pressure on a turbo).

btw, haven't done my air scoop yet, still experimenting on material. too busy din, dami work. why am i making one if i say the effects are minimal. kasi ayaw ko ng cai under the bumper. ok, maliwanag. hehehehe! peace.

[Karding]

it does not work as a turbo, but works well with the turbo, specially to cars with TMIC where hood scoop is functional 8)

RAM Air was originally designed (possibly pioneered by GM Motors) for such car as Pontiac Grand AM and Chevrolet Camaro. Pro yung aftermarket kit yata, BS lang. :mrgreen:

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My replies taken from same thread subject at HCP, pasensiya na 2 finger typist ako...

"My take has always been the same since nauso yang ram air na yan, it's the same as the author of the article.

There are many variables in designing an intake system, length of intake, diameter of intake, shape of the intake, even the surface finish of an intake has an effect.

Just because a gain was felt when a ram air intake was used doesn't neccessarily mean the ram air effect is responsible for the gain.
It's more due to the other factors, rather than ram air effect."

Seperate reply.....

"Re "cold air".

It's not actually cold but ambient temperature.

We tested the difference in the intake temp of an EK airbox using a drop in K&N filter taking air from relatively(water trap was removed) stock location & a remote air source(air ducted in from the area in front of the front right wheel, same vehicle same drop in K&N air filter, same weather conditions).

There was a 20' Centigrade temperature difference.

Engine bay sourced intake air was in the 50+ C, while remote intake was in the 30+s C.
The 20's C difference is significant enough to affect power output by a few horses."

And a reply from someone whose view re auto tuning is always valuable....

"KHRIS TAN
My take on this subject.

There is indeed ram air but the position we usually use is not right. Extensive wind tunnel testing is needed to find the right pressure point where the air entryi should be located. Usually the best entry point for RAM air is in the winshield area. Kinda hard and expensive to install it in an ordinary car. STupid also if you just gain a few ponies for ridiculous amounts of money. But if your looking for an advantage especially in NASCAR and BTCC where almost everyone has the same power then you'd do it no matter cost is.

In Honda's where the RAM air is installed in the headlight, My research showed that it helps at lower speeds but at high speeds it will actually hurt performance.

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yebo,
Ikasa mo pre' , appear! More or less yun na yun.

Ipost ko yung sagot mo dun sa HCP ha? Tyvm.

To add,
High air velocity(airflow) isn't neccessarily high pressure air.