I did the free ram air mod today. Went somewhat well. I broke the rubber pushpins on the ride of the air box. It was honestly impossible to get them off in one peice. Everything else went fine, mine doesn't look as good as the picture, but does it ever? Questions are do I really need to replace the pins, how much, and how much hp do you usually gain from this mod?

 

Im not sure want pins your talking about. I usually try to talk people out of doing this mod, its too late for you . I don't think the arguable gain is worth how quickly the air filter gets dirty. If you want it to have a ram air effect you have to block off the stock air inlet area or else all the extra air comming from under your car is going to just come out there. The hp gain is minimal but varies depending on how fast your going.

 

The FRA mod isn't really ram air. It's just a way to allow cooler air to get to the filter assembly. A true ram air has a sealed assembly that allows air to be forced into the intake (ie Super Sucker). IMO, the FRA mod gets you between 2-5 hp depending on the air temp & humidity. It's main benefit can be seen in the throttle response. I did it to mine and felt a difference even with the stock SS hood still doing it's job. The only pain in the *** thing is you have to clean out the debris a little more often. But, every little bit counts.

 

No doubt the FRA is getting more air to the airbox. But I highly doubt it's cooler air. It's drawing across a hot radiator as opposed to the direct feed to the front of the airbox ...

 

its the rubber push pins on the top right and left corner of the lower air box assembly. Do I need to get these replaced? And, if so how much and where?

 

I don't think it's that big of a deal. I broke mine off my airbox and had no problems yet. I heard you can get them at the dealer for a few bucks..

 

I thought so too when I just read what you posted...had to go and check to make sure I'm not talking out my @$$. The way it works is, the spoiler attached to the bottom of the radiator scoops the air up. Whatever air goes through the radiator...goes through and out the other side (out of the way). The air that doesn't go through either goes around the radiator into the engine compartment or (in the FRA case) into the intake. The heat from the radiator goes with the flow out the backside, not into the intake.

 

The air that goes into the into the FRA is going right across the face of the radiator ... no way to abrogate the laws of physics and to presume that air will not draw heat from the radiator .. now in fact that is probably very little heat, as long as the car is moving.

But in comparison to the fresh air that goes directly to the stock opening in front of the airbox, it will be warmer and can in no way be described as "cooler" ...

 

Then please explain to me why everyone does this mod??? If it brings warmer air to the filter, you wouldn't feel a difference. The car would feel more slugish. The fact is, if you blow on one side of the radiator, it comes out the other. When you're driving down the road, that's what is happening. What ever air doesn't go through the radiator either goes around it or is sucked up by the filter/intake. That air isn't near the radiator long enough to alter it's temperature when the car is moving.

Try this...go plug your hair dryer into the wall. Hold your hand at the back of it (where the air is sucked in). This is like the front side of your radiator when the car is moving. You can't feel any heat. But, if you put your hand at the other end where the hot air comes out, you feel all the heat. That is like the back side of your radiator.

That is why cooler air gets to the filter. On a Z28, the air that gets to the front of the box is recirculated air that came from the engine compartment. That is, air that has been through the backside of the radiator + air that has been near the block which is mixed with what ever minimal amount of air that makes it in from the front of the car. The black foam behind the grille does a nice job of cutting that cool air off, so it doesn't come from there.

 

Try your air dryer experiment again ... but this time put your hand on the heating element ... that is the true analogy to the radiator. The radiator is hot ... any air going across front of the radiator as well as through it, will draw heat off the radiator ... That's just plain physics and how a radiator works, there is nothing magical that distingushes the air going across the radiator from the air going through the radiator ... sorry you can't change that.

Since you went out and looked at you car once already ... go take another look ... this time look under the front bumper supports and check out the foam over where the grill nostrils are. You will notice holes about 6 inches square ... they feed directly from the grill and feed fresh air to the front of the airbox.

Never said the FRA didn't work it does provide more air and more air, even if it is slightly warm, is still a good thing. Just said don't try to believe that it is feeding cooler air than the engine is already getting ...

 

Granted your "physics" might work that way, but I always understood things to take a path of least resistance. If a radiator is emitting heat at a standstill, the heat that is transfered to the air will rise because that's it's path of least resistance...straight up. But, when the car is moving, there is a force that changes the direction that the hot air will flow. Between the turbulence from the spoiler and the fans pushing/pulling, the air that comes in contact with the radiator is pulled through to the other side.

Maybe I'm not interperting what you're saying correctly...but it seems like you believe that the mod allows more are to enter the intake, but it's warmer. If that were the case, then there would be no reason to do the mod. The difference between driving when it's 50 deg. out vs. 100 deg. out is huge. Cooler/denser air makes more power, right??? So, if warmer air was entering the intake, there wouldn't be a power gain, it'd be a loss...regardless of the fact that a small amount of extra air made it to the filter. And, maybe I'm just a stuborn punk...but I just don't see how what your are saying makes sense. Ok...I'm done.

 

I stopped reading about 4 post up.

Bottom line is if you are going 50-100mph the air isn't going to get warmer before going into your lid. if anything it will get cooler.

 

well guys i got .2 and 1 mph so im happy

 

The radiator is behind the opening. The air would be a little cooler if the radiator wasn't there but not by much especially when the car is moving, but its still not worth doing IMO.