The "spiralmax" works by supposedly making the air swirl, which leads to better cylinder filling and better fuel atomization.
While air swirl has been 100% proven to make such things possible, the spiral max has almost ZERO percent chance of making the air actually swirl in a car with multi-point fuel injection.
Here is the deal:
Have you ever looked at your throttle body? If not, it is basically a "flap" that opens and closes based on how you push the throttle. That flap in our car is about two inches in diameter and it almost completely blocks the two inch inlet to your manifold.
When your foot is off the gas, that plate is closed to restrict air going into the engine -- thus making less power. When you have the throttle mashed to the floor, the little throttle plate turns so that air can get past it.
The problem here is HOW the throttle plate opens. Imagine you have a big one foot wide pipe that air is flowing through, and how you regulate that air is by a big round dinner plate in the center of that pipe. The dinner plate in that pipe doesn't open like a door (so that it sits flush against one side as to be out of the way) but rather it rotates on it's center so that, while it's still "in the way of the air", the air only hits it's edges.
Did that make sense? Maybe some little drawings:
|--| Throttle plate closed
| / | Throttle plate partially open
| | | Throttle plate open
Can you see it? Air goes past that little plate, but that plate is "still in the way" of the air. Why does all this crap matter?
Because when you slap that spiralmax into your intake, it's "spinning" (uh, supposedly) the air BEFORE it gets to that plate. Unfortunately, since that plate is still in the path of the air, any spin that MIGHT exist suddenly gets cancelled out because of the flat plate "straightening" it out.
Even if that sprial max DID spin the air, and even somehow that spiral managed to go past the throttle plate, how would it get to each cylinder? You don't have to take anything apart to look at your intake manifold -- just look at it...
If air was spinning even after your throttle plate, it would never continue spinning when it has to break into four parts to move down the intake manifold runners to each cylinder. It CERTAINLY would also stop spinning when it hits the valve dividing wall in the cylinder head.
The deal is this: induced swirl is a good thing, but basically the ONLY place you can pull it off is by radically reshaping the CYLINDER HEAD; it has nothing to do with some BS part you slap onto your intake.
There are a few cars that will benefit from this device, specifically carbed or TBI/TPI injection cars. If the air can still be swirling when it hits the fuel, at least THERE it can help fuel atomization... But that isn't going to apply to anyone here who has a Hyundai.
-Red-