For the last ten years i have driven a 2000 f-150 with a 4.2l v-6 and manual transmission.Last month i had an opportunity to get an 05 f-150 with the 4.6l v-8 with an auto.The 05 is the slowest full size truck i have ever driven,my 2000 with the V-6 felt alot quicker than this truck.Is something wrong?Somebody please help!!!(the truck is stock with the exception of 20'inch wheels and a muffler that has two tailpipes running out of it.

 

It's just the way these trucks are. I have an 05' w/the 4.6 and it is gutless. I just ordered exhaust, made a custom CAI, and am going to get a programmer soon to try and wake this thing up!! I have been thinking about one of these as well http://www.americantrucks.com/75mm-bbk-throttle-body.html<input id="gwProxy" type="hidden"><!--Session data--><input onclick="jsCall();" id="jsProxy" type="hidden">

 

Wow... 20" wheels
I'd try re-gearing the rear-end (provided that its only 2wd) and a tuner... course along with the tuner i'd go with a CAI

 

Thanks guys,The truck had ridiculous 24 inch wheels on it when i got it so, 20's were actually a step down.I thought the change in wheels and tires down to the 20's would wake it up but,i barely noticed an improvement.Also a friend suggested that the two exit muffler might be too much flow(not enough back pressure) but, I feel like thats not enough to ruin the motors power that much.Feels like this truck is alot heavier than my 2000,Is that true?It's not like i expect this truck to be fast but,slower than my 4.2 was?

 

The important thing is the overall diameter of the outer tyre, the wheel size is unimportant as the 24" would have a thin narrow tyre wall.

Track down the original tyre dia from your model and then compare it against your set up now, or another way is to compare your speed at 70 mph against a standard road car, this will give you an idea if your gearing is messed with by having the wrong sized tyres.

 

Well the overall diameter is not that far off of the stock wheels and, tires(50 series off road tire)Not enough anyway to hinder it in this manner.The 24's were quite a bit taller and alot heavier.I would estimate them at approx 90lbs a piece.The 20's were alot lighter but,as i said no real gain in performance.This truck is at 2200 rpm's at 80mph,seems like really tall gearing.

 

you have a rear 8.8 axle with 3.55 gears


what you are seeing is a result of 2 things.


1. the 4.6 2v is a car motor. it requires high revs and doesn't have lot of low end torque. Works great in Mustangs...but not so much in trucks

2. a 2004+ trucks weighs at least 1,000 lbs more than a similar 1997-2003 truck.




you can do a few things to help out the situation though. 4.10/4.30 gears, tuning, intake, exhaust.


gears alone will make the truck appear to have gained 30+ horsepower. and if you are a 2wd, it will only cost you about $500. add another $500 for tuning/tuner and you will have a truck that is a completely different animal

 

btw, 20" rims suck. my stockers on the Expy run about 85 lbs for the rim/rubber combo. dropping down to a 17/18" rim will lose a little mass, but we are talking about maybe 5 lbs per tire.


the only way to really drop alot of weight would be to install some high end (read expensive) alloy rims

 

Where do I start? I have this issue of no power issue and it's jist frustrating, I'm not into racing or anything like that, but stepping on the gas pedal and to get no "punch" at all drives me nuts.

 

Maybe there are some problems, like a restricted cat converter, very dirty air filter, etc. When you goose it, it should downshift and give you some acceleration. Sounds like something is wrong to me. There have been several posts about 4.6L low power but that doesn't mean you should accept it without some checking.