Stock air intake vs. K&N FIPK

[propellerhead]

I've had my K&N FIPK for quite some time now but recently I decided to put the stock air intake in prior to a dyno special at the local speed shop. Here's what I got...

With the stock air intake (complete with the air silencer) and a K&N type filter.

Horsepower/Torque
216.15/249.41
224.2/273.3
213.83/245.11

Average of 3 pulls
218.06/255.94



I was bummed out. My previous dyno session were usually in the 230s. So, I had lunch, then went home to pop the K&N FIPK back in, then a few hours later.

Horsepower/Torque
218.58/250.7
231.97/271.24
223.99/256.18

Average of 3 pulls
224.84/259.37





Both runs were done on the same day.

The gain based on the averages of both sessions is +6.78 hp and +3.43 torque. If you look at the highest HP readings from both sessions, the gain is 7 hp. These numbers would probably be higher if I had the stock paper filter in during the first session. Still seems a better bang for the buck if you compare it to a 70 or 75 mm throttle body/plenum combo on a relatively stock engine. Putting both mods together will probably net a higher gain than each mod individually.

 

[CanadaStang]

Great info!! Thanks for sharing!

 

[ToplessStang]

I've always liked my FIPK but I feel even better now, thanks .

 

[jstreet0204]

While I would love to support your theory that the fipk gained you 7hp, what actually gained you the hp was the fact that you are running 5 points leaner in the last runs. You need to find the root cause of that soon.

 

[CanadaStang]

While I would love to support your theory that the fipk gained you 7hp, what actually gained you the hp was the fact that you are running 5 points leaner in the last runs. You need to find the root cause of that soon.

Yup, that's what I was thinking too, as the only run that has the same a/f ratio as the first run, is the run printed in blue, which is 218 hp [about the same as the stock intake]
The only way to accurately test a CAI is to have the tuner adjust the a/f ratio so that it is the same for the stock intake as with the CAI. The only problem is that I don't think I'd really want to spend extra money for dyno time just to test a stock intake.
Say, here's a dumb question, why does it say 89' 5.0 Mustang on the graph?

 

[hotmustang331]

WOW! A. there is somthing wrong with your car, or B. there is something wrong with his dyno.

Your car is SUPER inconsistent. And tell the guy to start the run at 1700RPMs in 4th gear. And also to scale down the graph to 0-300RWHP. Going to 500 gives almost no curve to your hp/torque.

The inconsistency of your runs makes your adverage HP gain of 7HP pretty much inaccurate. IMHO you should take it to someone else and get it dynoed. One of your runs were 11RWHP lower than the best out of that group. For whatever reason the 2nd run on both was the highest, and torque was sometimes almost 30 more?!?!?!

I did back to back runs before the cams...and 1st was 248.8RWHP/285.0RWTQ....2nd run was 248.9RWHP/285.9RWTQ. Thats ABOUT how consistent your runs should be.

 

[propellerhead]

I was waiting for you experts to chime in and pick this apart...

Isn't the a/f based on a fixed table at WOT? The EEC doesn't use the O2 sensors at WOT so it should be the same, right? I'm thinking the difference is in the tube they stick up the tailpipe.

The dyno does seem very inaccurate. It's like the Kmart of dynos around here. I figured if I go during their dyno specials, then I can get enough samples to have confidence in the results. Even the other dyno sessions I had at this place had variances of 6-8 rwhp in back to back pulls. Their dyno day specials are more of a car enthusiast get-together with free hotdogs and burgers. It is in no way meant to be a tuning session. This is also why I was going with the average per session, not the best run per session.

The dyno operator could not explain why 89 5.0 Mustang GT shows up. My name isn't even Martinez. When I pointed it out, he's like "Umm... I don't know."

My car has a 4r70w. He cannot start the run at 1700RPMs in 4th gear.

Either way, I'm keeping the K&N FIPK on. On average, it shows better numbers on the dyno than the stock intake tube with a K&N type filter.

 

[forpit2000gt]

IMHO, I think a place like that can get you into trouble real quick. Find a dyno that someone knows what they are doing.

 

[hotmustang331]

Ok...but all i am saying is that a dyno that varies that much run to run could EASILY create a false gain. I know the FIPKs make some power...but you really need a more consistent measurement of power to give TRUE gains.

The FIPK will flow more air into the motor, thus leaning A/F (a sign that it IS working and moving more air than stock with K&N...otherwise A/F would stay the same)...and your right about the EEC going into an open loop at WOT...so again when air intake is increased, the EEC doesnt compensate for it and the car will get leaner. That leaner condition also creates power in some cases.

 

[forpit2000gt]

to many variables. A larger filter can increase the amount of air.
What other mods done to car.

 

[hotmustang331]

^ Yea, whatever it is...smoother intake, bigger filter...it is flowing more air. Looks to have prochamber, Mac CB, FIPK, and handheld tuner...and we all know the bra gives 15RWHP.

 

[forpit2000gt]

the tuner itself could do this.

 

[CanadaStang]

Ok...but all i am saying is that a dyno that varies that much run to run could EASILY create a false gain. I know the FIPKs make some power...but you really need a more consistent measurement of power to give TRUE gains.

The FIPK will flow more air into the motor, thus leaning A/F (a sign that it IS working and moving more air than stock with K&N...otherwise A/F would stay the same)...and your right about the EEC going into an open loop at WOT...so again when air intake is increased, the EEC doesnt compensate for it and the car will get leaner. That leaner condition also creates power in some cases.

Actually the EEC should be able to adjust for the extra air from the FIPK, generally it's only the CAI's with the bend to the fenderwell that tend to lean out the a/f as the Maf doesn't get an accurate reading b/c of the bend. I was thinking the tuner had adjusted the a/f a little leaner, hence the one run that had an a/f of 13.5 and the other two were 14. Oh well, it still works out to about 7hp regardless. Thanks for taking the time to share the results!

 

[propellerhead]

Actually the EEC should be able to adjust for the extra air from the FIPK, generally it's only the CAI's with the bend to the fenderwell that tend to lean out the a/f as the Maf doesn't get an accurate reading b/c of the bend. I was thinking the tuner had adjusted the a/f a little leaner, hence the one run that had an a/f of 13.5 and the other two were 14. Oh well, it still works out to about 7hp regardless. Thanks for taking the time to share the results!

No tune changes were done between pulls. During these dyno day specials, they just do each pull back to back. No more than 5 seconds between pulls. No tune changes were done between the two dyno sessions either. Just the CAI swap.

I'm thinking the difference in the a/f was due to the tailpipe sensor. I have 3 other dyno sessions at that place during earlier months and they all show about 13.5:1.

 

[Mustangl3]

I think if you reset the computer it will have to re-learn how much fuel it needs at wot and should compensate for the FIPK.

 

[jposthauer]

Why is your hp so low

Why is your hp so low anyway on a 2004 gt? I thought the rwhp should be around 238 or so stock, unless you have an auto. But even with an auto that seems pretty low.

 

[Orions98GT]

heh, go go k&N

 

[hotmustang331]

the EEC adjusts for idle when the rear 02s are in use...it tries to get 14.7. My idle A/F for instance on Tims dyno was 18 lol. Before cams my A/F at WOT was 14-15. As far as im conserned the EEC does NOT adjust WOT trims. The preditor cant adjust the A/F eitherunless its manually set.

A/F is not all controlled by the EEC. If the A/F goes lean after a FIPK it generally means that there was a flow increase, meaning more air going into the engine but no more fule was added. At WOT the car goes into open loop, it refers to its base settings. thats why cars go lean after induction mods, a flow increase with the same amount of fuel = leaner. Thats the theory anyways...and in my car this was reflected. if you leave your cats and rear 02s functional then your idle A/F SHOULD stay at 14.7...WOT is different.

 

[CanadaStang]

the EEC adjusts for idle when the rear 02s are in use...it tries to get 14.7. My idle A/F for instance on Tims dyno was 18 lol. Before cams my A/F at WOT was 14-15. As far as im conserned the EEC does NOT adjust WOT trims. The preditor cant adjust the A/F eitherunless its manually set.

A/F is not all controlled by the EEC. If the A/F goes lean after a FIPK it generally means that there was a flow increase, meaning more air going into the engine but no more fule was added. At WOT the car goes into open loop, it refers to its base settings. thats why cars go lean after induction mods, a flow increase with the same amount of fuel = leaner. Thats the theory anyways...and in my car this was reflected. if you leave your cats and rear 02s functional then your idle A/F SHOULD stay at 14.7...WOT is different.

The rear 02's are only there to monitor the cats, they don't have anything to do with the a/f or the idle.
Yes a/f is controlled by the ECC, open loop is only used until the engine is warm, not at WOT.
The a/f will be a little on the lean side after installing an CAI b/c it needs time to relearn and adjust for the increase in air. After about 30 miles of driving or if you reset the EEC, about 10 miles, it will adjust to the new CAI.

 

[ScottyG00GT]

The rear 02's are only there to monitor the cats, they don't have anything to do with the a/f or the idle.
Yes a/f is controlled by the ECC, open loop is only used until the engine is warm, not at WOT.
The a/f will be a little on the lean side after installing an CAI b/c it needs time to relearn and adjust for the increase in air. After about 30 miles of driving or if you reset the EEC, about 10 miles, it will adjust to the new CAI.

I have heard before that the only real long-term benefit of a CAI is increased throttle response for the instant when you press the pedal - but after that, the computer adjusts so the A/F ratio is maintained at the factory setting, so you really don't gain any HP long-term after the computer re-sets itself.

That said, the argument for the in-fender CAI "fooling" the mass air sensor is probably true - I think that's how the C&L mass air housing makes power with the stock electrics - it flows more air than the stock sensor "thinks" it is because the flow characteristics through the meter itself are different, thus leaning the mixture and making power. This also explains why some people using these C&L's have tuning issues - sometimes they work great, and sometimes they cause problems.