Hey guys,

I,ve got a 99' F-150 with the 4.6. The mods on my truck are the FIPK, CAT back system (so the muffler shop said), a Diablo Chip and that almighty HP adding TB spacer. My question is: I had to take my truck to Ford and we now how they are about aftermarket parts. So I took the chip out and the FIPK off, thats it. I left the spacer on. Well I noticed that it had a lot better pick up at the lower rpm's(500-2500). Has anyone else noticed this? Do I just have a defective 4.6? I always hear most of the guys around hear talking about how great this product is (FIPK), but it does not seem to do the same for me.


I guess I should mention that I live in Houston,TX and it is always hot here. Most of the time its in the 90's and the humidity is usally always high. Any sugestions would be appreciated. Thanks guys.

 

read my post on "what RPM at 60mph"

the heat is your problem.

 

Thanks Whiteelephant. But come on guys, is there noone else in the Houston,TX area with this on there truck? Has no one else had this problem? Just give me a little feed back.....hell a yes or no answer would satisfy me. I just want to now that me and elephant man here (haha j/j) are not the only ones noticing this.

 

I have to disagree with heat being the primary problem. Heat is a problem with all the open element units but not in a particular rpm band. The claims made by the various FIPK makers claim HP increases like 14 or such. What they don't say is where these gains are made. The stock intake has been designed to compenstate for resonance frequencies that occur in the intake tract that can disrupt the intake flow. These will occur at the lower rpm's and can actually cause a HP and TQ loss. I've seen this proven on a dyno to be as much as 10% in other cars. That inner tube and outer chamber of the stock intake are linked and give an intake volume that can negate this effect. The down side is you might see a decrease at the very upper rpm band, not where you drive all the time. The majority of their gain is made by the low restriction filter. You can accomplish a better more streetable solution for real world driving by putting in a low restriction filter like the ACCEL power filter or K&N filter, then removing the intake snorkle going to the fender and replacing it with a unit that can flow 100% more air. This is what I did, works fine and acts as a cold air intake.

 

Irutt,
not that i disagree w/ what you're saying, but i think if one were to do the math on the losses due to the temperature differnce of engine compartment air and that of the the inner fender, i believe one would find a power loss substantial enough to be noticable. when using the FIPK i didn't notice the power loss as much when thre truck was moving (incoming cold air), although it still did not seem as good as the stock set up on the low end. so maybe this loss may be more attributed to the resonating air in the intake as you have pointed out. either way, i have to agree that the Ford engineers new what they were doing afterall. it's just that someone had to make it a high priority to keep the air going into the engine silent

my biggest beef about losing the low end "grunt" was how it affected the towing characteristics of the truck. towing 6000+lbs and not being able to get it out of the hole as easily as stock was not something i favored.

 

I do agree with the effects of the hot air while sitting or moving slowly. I also am glad to see some confirmation to the issue of lowend torque loss with some of the FIPK'S.

Oh well, people can put whatever they want on their truck.

How did you mod your snorkle going to the fender, or did you?? Mine measures about 3.25" and goes through the innerfender like stock. I formed a bell (velocity stack) from aluminum and attached it to the stock filter housing. I also used the dual foam element ACCELL filter as it traps more dirt than the K&N's.

 

If you look at the claims that FIPK and cat back exhaust makers claim, these are peak hp/torque numbers. You do give up low end hp and torque when you free up the exhausts backpressure. You start picking it up (over stock) at about 2200 rpm.

 

Irutt,

sounds like your intake is a little more sophisticated than mine. i didn't bother to make a velocity stack. good idea though. if you read my post under "what RPM at 60mph" you will see what i did. i really hate cleaning filters, so i just use the paper type. let me guess, you got the foam filter idea from the bikes huh?

let me know if you have any other questions about my mod. it's rather simple.

by the way i like your collection of rides. you could use a couple dirt machines though!

mine include:

96' CR250
86' CR125
02' CR250 on the way!

 

White Elephant & Irutt,


Thanks for the info, also thanks to all the others who helped. I would like to get a little more info from you 2 guys on how you set up your factory air box. I am more than likely going to take off the FIPK and try to do what ya'll have done. If ya'll could or would shot me an e-mail with a describtion on how you did this mod (dmatthews@epglobalnetworks.com). Thanks guys.

P.S. Whitey, I'm a fellow dirt love myself. I've got a 97' KX250. Have you ever been to the extreme dirtbike site. Check it out its cool.

 

I have a 96 CR 250 as well...LOVE IT!!! We're all headed down to Chadwick today at noon. Can't wait.

-AR

 

I used to motox in the early 70's. I had a DT1 and DT2 Yamaha 250 back then, Basanni pipe, Webco head, Wiseco piston, custom porting, they were quick. From the late 70's through mid 80's, used to just dirt ride with a bunch of buds. my last ride being a trusty XR500 Honda and TT500 Yamaha. I used to dirt track in the midwest with a moded TT500 Yamaha which I still have. I'd like to get into play riding again, I miss it, Either with my old short tracker or I have a line on a nice old XR500 real cheap. Riding sucks in Central Florida though. No places like in Nebraska with nice big hills etc. Just sand and crap, I don't call that fun.

 

I just installed an fipk on my truck and i have noticed a slight drop in low end but it makes up for it once you hit about 2700,that and the cat back exhaust work pretty good together.the mileage is about the same.I raced my friend in his subaru the other day,and that's when i noticed it,we were neck and neck then i hit 3,000 and pulled away,i might put the stock intake on one day and compare.

 

Irutt--dont get me wrong here beacause I agree with alot of stuff you mention...You used sheet metal....Is it exposed to under the hood temps???

Metal is a heat sink and will effect your air temp as well....

I used rubber or plastic which acts as a insulator...

I used the rubber boot for a snorkel (3") to collect air from the fender...

 

I only have a short stretch of black painted aluminum, about 6", that is exposed to the engine compartment heat. The rest extends into the fender well area. The heat impact would be very minimal in that area.