Chris06GT

Hi all,

I read somewhere that a properly functional "ram-air" hood is equal, in terms of performance, to a cold-air intake. I'm talking about a ram-air hood with a stock intake, or vice versa.

Can anyone confirm if this is true, and if so, is there any advantage to go with one over the other? If you go with both, is there any advantage?

Thanks- really enjoying these forums,

Casey4s

Why not do both? You will definately benifiet from a CAI, but added cold air from a scoop or functional hood is always a good thing. I would be willing to bet that the functional hood alone will not produce the gains that a CAI alone will produce. That is my opinion and I have no technical data to prove it.

SirKnightTG

Not on these cars. Ram air scoops/hoods don't do jack other than looking cool.

Get a CAI + tune combo from Brenspeed and call it a day.

shanec

Ram air does nothing. Worst case, a functional ram air hood hurts the car by forcing air in that the car doesn't want, particularly at idle and when the driver lets off the throttle. Nothing to gain from ram air.

Chris06GT

Is there any reason why it doesn't work on these cars? Obviously the technology works on some cars otherwise no one would use it. For example, with shanec's Cervini Type IV hood you can order a ram air kit. Are you saying the kit does nothing?

sactown

With the stock air box a ram hood is going to do nothing but allow cooler outside air to be forced on top of the air box. There is not an opening on the top of the air box, the air box is designed to draw cool air in from the opening in the fender well next to the box.

With a CAI I would think that having cooler air forced down on top of the CAI would have some benefits at higher speeds, but not just driving around town, but they do look good.

This is just my opinion.

DLZ314

Not that Ram-Air isn't functional, but its far more cosmetic. Take a look at Subaru's STi: huge ram inlet on the hood, yet the aftermarket is flooded with kits that move the intercooler to a front mount scenario.

Instead of Ram-Air and trying to get cool air in, check out a cowl hood and focus on getting hot air out. Heat soak will rob you of more HP than a hood scoop will help you gain.

Nuke

Ram air is only funtional if that air is being rammed (hence the name) into the TB. A ram air hood scoop on our cars might help the engine to cool a degree or 2 more but that's it. I don't recall seeing anyone making a FUNCTIONAL ram air system for S197's. A ram air hood with a stock intake OR even with a CAI won't do jack for performance.

shanec

Not only that, but air alone is not going to give anyone a performance gain. The car has to be tuned for the amount of air it takes in when the throttle body opens by x amount. You can't just force air in and expect anything to happen. If anything, its going to make the car run lean.

This is why CAI's require a tune. More air in = tune change to see a benefit.

Nuke

Another issue to keep in mind is the amount of air the engine can actually use effectively. An engine can only "gulp" so much air and anything more than that is useless. With our current S197's (provided you're not FI or modded internally), our TB's along with a CAI & tune makes use of all the air that can be had. You can force as much air AT the intake but it's only going to take what it can take. Period.