I think opening up the exhaust does help with HP, but I really noticed a difference when I added the air intake. My Raven muffler is not real loud, can't hear it with the radio on, but when I get on it I can really hear the intake! Sounds great!!

 

Check local exhaust shops, not just Napa or someplace like that, I almost got the same thing done for $20s at a no name muffler shop(- the muffler of corse).
This would of been to weld the flowmaster on and then get a pipe extension, b/c the stock muffler was like 33" long and the flowmaster wasn't even 20".

 

Well, now, that ain't exactly true, either. The reality is that if you add more intake air, the computer will compensate by adding more fuel, to try to achieve stoichiometric combustion. Adding more fuel will increase power, but not fuel efficiency. If the A/F ratio is leaned out, that can increase fuel efficiency. If you drive the car easier, that is, use the accelerator less, then you can improve MPG. But let's face it:

1. Increasing air flow by replacing the air filter isn't going to make a significant difference.
2. Decreasing muffler back pressure by replacing the exhaust system cat-back isn't going to make a significant difference.
3. Doing both will help more, but still won't be overly substantial. Noticeable, yes, but very arguable as to whether it is "worth it" unless intangible benefits, such as a desired exhaust note or decibel are factored in.
3. Reprogramming the ECU will make more difference than either of the above because factory programming settings are deliberately lean for EPA emissions issues. The standard ECU re-map takes advantage of this by providing both a richer mixture and also utilizing changes that can be made when premium fuel is required (spark advance, etc.)
4. When the manufacturer redesigns an engine for more power and/or fuel efficiency, they aren't just simply replacing an air filter and a muffler. They are changing headers, cam settings, valves, utilizing computer technology to better control more and more of the combustion process and so on.

Increased power does NOT necessarily mean increased efficiency. Sometimes you get one or the other, sometimes both. But you're not going to get any significant increase in fuel efficiency from your vehicle unless you are prepared to invest more money than will be returned on your investment unless you plan on keeping the vehicle for an awfully long time--longer than most people would.

If you want realistic gains in power, you need to be prepared to spend realistically large sums of money to make real changes: cam, super charger, turbo, etc.

 

Hello All, <O</O

I have to say this is a great site, got a lot of info here. I'm new to these forums so thanks for all the help.<O</O

As far as this topic I had to post. I installed a Roush exhaust on my 05 FX4 Super cab along with a K&N filter. This did wake the truck up considerably especially in the acceleration from a dead stop. The sound is great not really loud but deep, on the likes of a Mustang cobra. Now these days gas MPG is a major concern. Stock I would get 17 (2000 RPM @ 70-72mph) at best on the highway after installing the new exhaust and filter kit it went up to 20mph under the same conditions. So I have to say the cost of the exhaust is worth it you get some performance looks, sound and MPH. Now if I can find some tires that are not $300.00 each.<O></O>

 

Howdy BruteFX4,
Once you add your tires your mileage will take a hit due to weight and surface area (drag) on the road. But let me know about tires, I am putting on my leveling kit friday and will need to fill some wheel well!

 

That just it, not sure what to do. Currently I have the stock 285/75/18, just to replace them they are $300.00 each. I'm looking at tire wheel packages. What do you think is the smallest wheel size that I can fit. I love to put a set of 33/12.5/15 but doubt the rim will clear the brake caliper. I never measured but I think I will be stuck. Any suggestions? The leveling kit, I assume is to bring the rear end down correct? Sorry for all the questions, this is my first Ford comming over from Mopar, so not sure of all the set-ups.

 

The leveling kit brings the front up to match the rear.
Sorry, but the smallest wheel you can fit are 17, which sucks in some ways.

But your mpgs should be to bad with new tires, what gear ratio are you running?
3.55, or 3.73?
If you have 3.73 then going alittle bigger will not hurt.

 

Thanks for the reply,
My truck has the 3.75 rears, so the new skins should not affect much. Where are you guys getting the leveling kit from, I can't seem to find it anywhere I looked. I like the idea of bringing the front up a bit.

 

I think Daystar, and Rancho both make a 2.5" leveling kit. I belive there are a few more too.

 

here is one company that makes a leveling kit that does not require a spring compressor. www,extremetrucktoys.com

 

Thanks 396, My 2" leveling Kit is on the way from extreme.

 

Be Careful guys... some of us are getting damage..

 

blazin is that acutal spring damage or just the coating on the spring ?
any idea what could have hit it?
and 1 other question which kit do you have

 

We should probably start another thread for this... but ill respond anyways..


i thought it was just the coating, until i took a closer look, its starting to rub the spring itself. Cant say its getting any deeper than pictured, but yes, it is touching spring.

Im assuming when the truck is at Full Droop (ie:20mph over huge speed bumps, cuz God knows i havent gone offroading in forever), i think its the upper/inner spindle thats hitting it.


EZ-Lift, but alot of people that have leveled out their truck with almost any kit are feeling it.

check f150online, and search for the thread labeled "Bye Bye Auto Spring"