I guess I am one of the few guys with the 4.6 as opposed to the 5.4. The Dyno sheet for K&N doesn't look too impressive for the 4.6L. I have the True Flow and I can't tell any difference between that and the stock setup. I have a Magnaflow exhaust SI/DO and I expected better acceleration with the True Flow CAI, it just isn't happening.

Will K&N be any better? Volant appears to be the same as True Flow (closed box design) so I don't think that is the answer. I just figure that with the K&N you have more air going in so more air can go out.

Am I just being a total dumb a$$ or will a change in design make a difference?

PS- Yes, I know a programmer is better. Right now I just want to focus on the CAI.

 

I have seen other posts asking pretty much the same question.
With all I have read here is what i understand.
The stock intake system on the 4.6 is a good design to begin with, therefore one would not really experience a large gain in this area by replacing it.
I like many have taken out the silencer tube in the stock intake and put in a Framn Air Hog air cleaner. That coupled with my exhaust has slightly improved the mid range performance.

 

I've got a 4.6 as well and haven't considered a CAI. Not much talk of them makes me think there's no real gain. You know how people see even a little gain and they're sure to share it. I took out the silencer and dropped a K&N in and saw a little gain, nothing exciting though. Perhaps something rigged up to draw in colder air than the fender would help.

Mike Troyer, like him/his products or not he knows a good bit and at least deserves a listen, noted that the 4.6's run lean enough that adding more air could possibly be a bad thing. (http://www.f150driver.com/forums/sho...light=silencer) I haven't read this in months so I could be completely offbase.

I guess there's some opinions and options out there, but none strong enough for me to gamble the cash, yet.

 

I added a K & N drop-in filter and noticed no improvement in acceleration or reduction in throttle lag. A month later, I removed the silencer and noticed commendable improvement with acceleration and the throttle lag vanished. I'm not sure if the K & N helped or not.

 

I just replaced my stock filter with a K&N filter this past weekend, and i could instantly detect a huge difference in the throttle response!!!!! Seems like it has a little more " get up" now, and my Magnaflow sounds a little louder! Very happy with it!

 

I've done the K&N drop in (very small power increase, decent gas mileage increase on freeway, no difference in town) and a full AEM Brute Force.

Net result, as has been said, the stock intake on the 4.6 is a pretty good intake.
I have not pulled the silencer, but may if I ever go back to the stock tube.

Tuner makes more difference to this truck than exhaust or intake.

The 4.6 has the same size exhaust as the 5.4, so you get less gain by upgrading a 4.6.
And since the intake has been around long enough to be debugged it works OK.

So if you really want more power do gears. The 8.8 rear is much cheaper and easier to get things for than the bigger rear under the 5.4 trucks.
Chris

 

Will it make a difference that I already installed a SIDO Magnaflow exhaust? I thought that with the exhaust I needed more air, that's why I got the intake. Will I be ok going back to stock?

My other idea is to change from True Flow to AF1 for more air. Still wouldn't make a difference?

I am totally lost about the gears. What info can you give me so I can better understand your answer?

 

Hey BFan,
I have a simliar desire to improve my incoming air and have yet to decide on an intake. I have pulled the silencer and dropped in a K&N hi-Flow and did notice a difference--but I would like more. Who wouldn't? In any case, the K&N seems to be the route I'll go unless I can get numbers from AFE or S&B that look better. Problem is not many people are using either setup and even fewer have bothered to mod their 4.6's.

 

I did the K&N drop in and pulled the silencer,I could tell I had done it.It pulls more from a stop and has a little better mpg.I have an Xcal 1 tuner for mine and am looking for some thing else.I have had issues with pinging with every tuner I have run on this truck.I think a nice super charger would be sweet.But cash is in hi demand around here now.I dont think I would spend the money on a CAI I just dont see it netting a gain large enuf to make it worth it.

 

Didn't see your response till this morning.


On gears, you take the truck into a shop and have them change the ring and pinion gears in the differential (rear end) to a lower (bigger number) set. This gives you more power in the gears.
It’s sorta like adding a lower gear in place of low, and removing the top gear (OD).

Thus you get lots more power through all gears, but lose some top speed.
At least on paper.
These trucks could, if you turn off the speed limiter, go up about 130-140 miles per hour. With say 4.10 gears the top speed is lower; say about 125-130 miles per hour.
With the lower gears your engine will run at higher RPMs all the time. You often lose some gas mileage on the freeway and on these heavy trucks you may even gain some gas mileage around town.

Changing the rear gearing is the most power you can get from a simple mod.

Example if you pulled a set of 3.55 gears out and replaced them with 4.56 gears, while never changing any other thing, your 230 horsepower would feel like 295 horsepower. For 500 bucks installed you would get a 28% power improvement.

Of course with that big a jump you would be spinning tires, and getting about 20% less MPG on the freeway.

Intake and exhaust mods are greatly improved by gear changes since most of the gains in these mods take place at higher RPM’s.

A nice practical amount would be to take the rear gears from 3.55 to 4.10. This would give you the equivalent power improvement as adding 26 horsepower, or more than you can add with intake and exhaust.

If you already have a decent exhaust that increase would be even more.
I have driven the 5.4 with 3.55 gears and then with 4.10 gears.

No comparison around town driving. The 4.10 truck just plain spun the tires, the 3.55 was ‘OK’.

There are hundreds of threads on gear changes in this forum, but note that most of them are about changing the gears because they put larger tires under the truck, thus are mostly trying to get back to the stock ratio.
Chris

 

I have this on my 4.6

[IMG][/IMG]

 

Very well explained Chris. Not to hijack, but wondering if you could clear something up for me while we're on the gears. I live in a mostly hilly area, lots of long steep hills and I've got 3.55's. A horrible combo. Going up some hills at 2000-2200 rpms gets me maybe 30-35mph, would a 4.10 at the same rpm get me going a bit quicker, say 40-45? I'm under the impression that the lower gearing would take a higher initial rpm to get to speed, but then a lower rpm to maintain it up the rest of the hill. Am I understanding that correctly?

I've stayed away from upgrading the intake/exhaust due to the 3.55's and hills round here, just don't think it would worth the slight gains for the money. I've considered regearing, but that's not for sometime down the road since I'd have to do front and rears. I kick myself for not getting 3.73's but I bought right before the deals ended and the 05's were running out so the pickin's were slim.