Say an intake or air filter can give up to 26 HP when it barely gives 1 or 2 in reality?

 

would you buy it if they claimed -2 hp?

 

Point taken

 

well they can provide that much... if your running a fully built motor with 40 psi boost on a stock intake... upgrading to that will get you 26hp lol

 

It depends on which type or area of horsepower you're looking at. When we, as owners, look for performance increases in parts we are looking at gains with peak horsepower. Intake vendors measure the horsepower gains anywhere they can find them.

For example:

K&N advertises a 12 or 15 hp increase above stock. What they don't say is that is peak horsepower which we measure at the top of the RPM band. Instead, they run a stock dyno and then another dyno with their intake on the car. They then find the area on the dyno curve where the maximum difference in hp exists.

It could be at 5,000 RPMS or maybe even lower...but they then say "LOOK! We produced 12 more hp @ x amount of RPM's" so they slap that on a package and send it out. Nevermind peak hp doesn't change.

In many cases, intakes don't produce exta power via extra airflow. The vendors simply understand how the Mass Airflow sensor works. They alter the intake tube to trick the MAF into thinking less air is coming into the motor and as such the ECU adds less fuel.

This creates a slightly leaner mixture which, as we know, results in power increases.

Some intakes have genuine effects such as going to a cold air intake from a short ram. The RX8 intake is already well designed and needs no more modifcation than a better flowing air filter.

 

the AEM/mazdaspeed or racing beat+duct is going to be an improvement simply from the fact that they put the entrance to the filter (or the actual filter) directly in the air flow.

 

thats just what they do lol

 

why does ebay advertise 75 whp for 12 dollars?

If you're buying an intake, buy it for other reasons aside from power gains which are nonexistant.

For example, I bought my K&N typhoon for looks, I love the carbon fiber and the sound. I knew I wasnt getting the claimed 10 extra horsepower though.

 

for the same reason that people still buy those "performance chips" on ebay.
sucker born every minute...

 

Because if your car has 150,000 miles and you've never changed the air filter EVER, changing your air filter will actually net you 15 HP

If you maintain your car, you'll see nothing.

I've got a bottle of MAF cleaner that advertises 4-10HP gains

 

you really can get a lot of power on some of those cars, like an 03 cobra

 

Mazda 3 plus KN = 25.6 HP

That is the add in this forum that I am reading now.....

I doubt that much is possibe on such a small motor.

 

NOS sticker adds 15whp!!!

 

ok ok ! I'll tell you my secret.

I put Barney in the back seat and his big purple dinosoar feet get me an extra 25 RWHP

 

big purple what?

 

I think it's the Mazdaspeed 3 that responds like that. Small Motor+Turbo. But 25 sounds like a lot from just an intake.

 

1 HP is, in fact, well within the range of "up to 26 HP."

 

Exactly.

In fact, no gain at all is still entirely possible within the range of "can provide up to 26hp" Words are everything.

And I could see 26hp actual gain (somewhere in the curve) for a car with a horribly designed stock intake piping/routing, etc... For example, the 02 Corolla did actually see a dyno gain of ~7hp from a CAI over stock (yes, it was still POS slow). The stock intake and air box had tons of air baffles and the filter sits about 4 inches from the exhaust manifold with a flimsy heat shield in between. The CAI didn't provide cold air so much as it stopped the massive heat-up of the air, as well as got rid of the baffles.

So all these companies have to do is find a car with a truly awful stock intake system (doesn't even have to be a car currently in production, or even within production for the past couple decades) to get the max gain possible, and cover themselves legally with the words "can" and "up to".