Here's the email I sent to them:

Sent: Tuesday, March 06, 2001 7:32 AM
To: tech@knfilters.com
Subject: replacement filter vs fipk

I have a 2000 Suburban w/5.3L and will soon have a 2001 F-150 Super Crew w/5.4L. They are used as primary family transportation and off-road for farming, hunting, fishing and to haul or pull light to heavy loads both on and off-road. Rarely if ever are they run WOT so I don't care about top end gains. I'm looking for better low and mid range performance along with increases in fuel mileage. As of now, I plan to add Gibson single-side cat-back systems to both and either a K&N replacement filter or FIPK which is where the question begins. For my stated usage, which is better for me? I believe the replacement is listed as "up to 7 hp" and the fipk "up to 20 hp". Base on that you would think the fipk would be better but 20hp @4500 rpm means nothing to me. I'd be more interested in 1500 – 3500 rpm numbers for the two. Can you provide some info on these two options on my two applications?

Thanks,
Mark


And here is the reply:

-----Original Message-----
From: richardb@knfilters.com
Sent: Wednesday, March 14, 2001 11:24 AM
Subject: RE: replacement filter vs fipk

Dear customer,

Intake (filter or kit) and exhaust systems both help more with top end performance more than low end. Low end is usually affected by mechanical changes such as gear ratios and cam shafts. Our dyno does not even begin reading until 2200 RPM. Max gain is at 4500 - 4800. However, some separation (gain) is apparent at that 2200 mark. We do not yet have kits for your vehicles, both are do out later this year, summer. Our drop-in filters will give a 2 - 4 % horsepower increase and our kits give a 5 - 7 % HP gain. Actual performance depends on the horsepower available to begin with.

Thanks for asking, Rick


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2001 F-150 Super Crew Lariat (on order)
2000 Suburban LT
2000 RC51
1999 Mustang GT Convertable

 

edit

[This message has been edited by max mitchell (edited 03-15-2001).]

 

Yes, I know that an increased airflow capability isn't fully utilize at part throttle. But with all the banter about filters vs. FIPK vs. free air box mods I wanted K&N to say it.

Also, I think that my "normal driving conditions" described in my email are not that different from a lot of truck owners. So, again I wanted K&N to answer. I'll let those that read it draw their own conclusions.

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2001 F-150 Super Crew Lariat (on order)
2000 Suburban LT
2000 RC51
1999 Mustang GT Convertable

 

SuperCrewMark,

Most hotrodders know this already. It is a good point for those who are new to the sport or who did not know it.

Regards

Jean Marc Chartier

------------------
00 F-150 XLT SC Flairside 4x4 4.6 w/5spd 3.55LSD
Warn XD9000i, skid plates, Draw tite class III,
Rancho RSX Reflex shocks, MAC 8.8 Axle Girdle
BFG 285/75 R16 MTs,
Borla Cat Back, Headman Headers,
Custom air intake system with modified
air box, Ported Throttle body,
Shortened MAF sensor tower,
K&N air filter,
Superchips

 

edit

[This message has been edited by max mitchell (edited 03-15-2001).]

 

It's my fault for not being more clear. I've played dumb with the chip guys too. Actually, I am new at truck mods with only a K&N filter and Gibson SS on the Burb. Nothing on the SCrew as I don't have it yet.

But, my '99 Mustang GT has a MAC Cold Air induction system, underdrive pullies, Bassani X-pipe, MAC one-chamber cat-bat (talk about a mean sounding ride!), P275/40ZR17 tires on 17x9 "R" wheels and is lowered with Kenny Brown springs.

Most of my experience with with motorcycles however. I've done a lot of work on them including my current bike the RC51. There is a very cool product called a Power Commander from Dynojet that allows you to change the fuel and ingition maps for fuel injected bikes every 500 rpms to redline and every 10% throttle opening up to 100%. I've been doing a little work with it and will be putting it on the dyno again soon.

------------------
2001 F-150 Super Crew Lariat (on order)
2000 Suburban LT
2000 RC51
1999 Mustang GT Convertable