whats the best bolt on performance mods for the gas engine, there are so many different things and manufacturers its hard to decide


2004 F250 SD
9" lift 37" Iroks
5.4L V8


Im lookin to get more HP but want the best recipe for increased torque too.


BTW, why cant I find the option to add a signature, I dont see that option it in my profile or anywhere in the UserCP for that matter

 

i went with k&n air filter with magnaflow exhaust and superchips power programmer. just simple mods but helped out a lot compared to stock. i have the two valve heads so i was hurting for power to begin with

 

You won't be able to add a signature until you have a certain number of posts, 25 comes to mind but I could be wrong.

As for your truck, the best performance mod you can do, especially with the 37s is to regear your differentials. 4.30s or even 4.56s would increase your torque and pulling power. Surprisingly enough, it doesn't seem to hurt fuel economy. Some 5.4 owners even report increased economy around town with the lower gearing.

 

I forgot to mention that I already have an AFE cold air intake
I want to regear it too but I want to wait till after I get the 41s

 

When do you plan on going to 41s?the loss of power is from the tires.Gearing will give you the largest gain to give back the tourque lost.It is also easier on engine/tranny.Aside from gears there is the normal stuff,exhaust and chip.You can super charge it too.

 

Aside from gearing, air box and exhaust, you have some options internally, depending on how much $$$$$ you have.

Cams, stroker kits and head porting will get you a monster V-8, 6.0 liters with about 480 streetable HP.

 

tuner was far and above my best power mod. i don't have the PI heads either, so i needed it.

 

ok as I stated before, I already have an AFE cold air intake
I should have my cut-out flares and 41's on in about a month, then Im looking to go with 4.56 gears, I want to change the exhaust also and I was thinking MagnaFlow or Flowmaster.......what are you guys opinion on the exhaust?
I also want to put in a chip/programmer but I dont know NOTHING about them so I dont know what tuner to go with.
When I did my car I sent Superchip all my new engine stats, new gear ratio, exhaust size, tire size etc etc and they custom burnt a chip just for my car and it works great. But I dont plan on changing internals on this engine, I just want to maximize the potential hp of the stock engine.

 

In gears I would go with 4.88/5.13.They would get you closer to a stock ratio.

 

The thing about chips particularly for a gas engine is that they aren't going to give you that huge bump up in power that you would get from a chip designed for a diesel. Since you are going to lose power with the bigger wheels and your going even bigger pretty soon(if I'm reading your post right) your not going to regain the power that you lost from the bigger tires and more weight your putting on your truck. I would do the regearing for sure, you should do the chip, but I would do a custom chip and also do some type of forced induction and bigger injectors and have the chip programmed to accomodate for that. I just don't think a chip, intake, and exhaust is going to satisfy you when your wanting really good power increases and your also going bigger and heavier with your truck. A stock 250 with a 5.4(I don't know what you stock gearing is, but I'm going to assume that it's a 3.73, maybe 4.10 but I think that you would have to order that or someone would have had to order the 4.10s most 3/4 tons come with 3.73 from factory that I have known anyway unless special ordered differently) is sufficient for the truck when left in stock form, you have added a lot of weight and going to add more and you have the 9" lift to add even more wind resistance, if it was the v-10 or diesel I wouldn't be as concerned with it, but I think that the lift and bigger tires hurt the gas 5.4 just enough to make it a push on what to do. Just my opinion for what it's worth, but I would think about doing a little more internal stuff to really help max the potential of the engine.

 

I second that 41's are big. Guys run 4:30 with stock tires.

I would get an SCT SF/XCal2 and take it to the dyno and get it dyno tuned at a local dealer. A premium gas tune at the SCT dyno should be able to pick up more than 30hp and 30ft lbs, not to mention adjusting the tranny and tons of other parameters.

I believe Comp cams makes a set for the 5.4 that will give 30-40hp gains.

A set of headers will help.

Or look for a blower. The gears are the main thing need first.

Also be sure to post pics when finished.

 

I got a valve body from Fatcory Tech and installed it. No chip, but I get a pretty good second gear scratch in the beast when I nail it. Sure took care of those mushy gear shifts in the 4R100. $200, some tranny fluid and about half hour and it's done.