Would the drop in K&N = the same performance increase as the no tune Airaid, Roush or the no tune C&L? Airiad and C&L both say an increase of 11rwhp. Roush 8rwhp. The K&N in the stock airbox should net the same shouldnt it?

 

In short. I'm going to say no.

A drop in filter isn't the same as a whole different intake setup.
Stock you 5.0 guys are at 748.7 CFM (cubic feet per minute). 50 CFM less than us in the 2010 GTs. (stock) which due primarily to the Throttle body in the '11.

The C&L no tune opens up 1,096 CFM because of it's filter and design.

The K&N is taking the stock filter and replacing it with a much better filtration one. However the flow pattern remains virtualy the same as it's in the same housing, but it does increase it to what K&N states to be "up to 900 CFM". Which isn't bad.

More air entering increase combustion efficiency which... resulting in more horsepower & torque. FRPP uses this filter in one of their tuner packs...


I had a K&N Filter on my 2010 GT before My Steeda CAI for about 2500 miles. The one thing I definitely noticed was it breathed better and sounded a touch better. But really didn't do much in terms of performance, maybe a few HP.

In a shameless plug:
I still have my old K&N filter if anyone is interested... I'll even clean it, oil it and ship it.
$25. any takers!? Shot a PM.

 

I have a K&N drop in. Its sold as a 1 to 4 horsepower increase. I'm waiting for the C&L no tune c.i.a. for my V-6.

 

I put a drop in K&N filter because I wanted to increase air flow without commiting to buying a CAI system right now. I'm waiting for more companies to release and maybe even perfect their CAI systems as well as hopefully getting more dyno results and people's impressions/reviews before I buy one. Although I have been looking at the Steeda and Air Raid systems because they both use the factory cold air feed from the front bumper and that's always a plus. With the drop in K&N, I have noticed an increase in gas mileage (1-2 mpg) and some better mid range rpm performance while still using the same driving style. With the exhaust system I just put in, the increase in performance is even more noticeable.

 

The drop-in is a nice simple thing if you want to keep the airbox, but I'd look at the C&L or Airaid. The Roush looks cheap because it reuses part of the stock intake hose, which I don't care for.

Why not just go for something like the Steeda intake with the tune to help with other aspects of the car, like throttle response?

 

As others have said depending on the car itself, the K&N drop in usually adds 1-4 hp, and in some cars nothing.
I dyno tested the K&N drop in filiter in my BMW 335i a two years ago and gained
3.8 rwhp
2.5 rwtq

This was on same dyno, same day. Just did three runs stock drop in, let car cool for 15 minutes, put K&N in and did 3 more pulls. 1st pull with K&N was like 1 rwhp and 1 tq higher than stock, then pull two and three were both around 3.5-3.8 rwhp gains from stock.

When people say they felt more power from a K&N drop in, it is purely placebo effect.
There is no way you will feel 1-4 hp in a car with 300-400 hp to start with.
Maybe in a 100 hp 1.5 liter car, but in those instances you would be lucky to gain 1 hp from a K&N drop in.

 

Is it a myth or would a drop in filter also increase fuel efficiency?

 

Pure placebo when you read people say, "I've gotten 1-2 mpg better gas mileage since putting in the drop in filter."
I can't help but laugh my butt off at those comments.
If they got 1-2 mpg better gas mileage after putting in the drop in, it's simply because they were either
1. Doing more freeway driving
2. Not driving the car as hard during that tank

Anybody think they can improve gas mileage by 1-2 mpg (that would be to 5-10% better fuel economy on a car that averaged 20 mpg) simply by changing their air filter to one that allows maybe 5-10% more air in, I've got some stuff to sell them.
If that was true and in these strict EPA regulation times, if manufacturers could get 1-2 mpg better gas mileage simply by using an different drop in filter, they'd do it.

Further, many modern ECU's have set Air to Fuel ratios for optimum running of their stock cars. In many if you add more air the ECU will adjust by adding more fuel so the engine does not run lean.
Well guess what? Where do you think that extra 1-4 hp comes from?
You guessed it, more fuel to compensate for more air.
If anything you are going to get a bit less gas mileage if the stock ECU adjusts to keep it's AFR in the engines designated safe zone to avoid knock.