I have a 2000 5.4, I have researched the 5 star tunner and have not found much on which octane gets the best result. I would like to stay away from 93 because the .50c increase per gallon isnt worth it. However, I have 87 and 89 octane around where I live. I have seen people get the 87 perf and 89 perf, 89 tow.

Also purchasing the y pipe from 5 star, is there any other products that are worth purchasing for the 5.4 to improve performance besides re-gearing??

 

Have you thought of doing headers during the y pipe install?

2004 F250 Broken Exhuast Manifold Stud

 

The higher the octane fuel the more power you can get out of it with the tune. The 87 and 89 octane tunes are good for most people and most stations carry either of those two. What I use the most is the 87 perf and the 87 tow.

The y-pipe is a good addition. An aftermarket intake will add some top end power with the tune but nothing big. The tunes will help the most without getting into gears or power adders.

 

Been there done that on my 5.4, save your money and do better mods instead

 

I have not, but now I will plan on it when they need to be replaced. Putting the $700 plus dollars to lift, rims, tires first. I need an exhaust shop put in my y pipe since I do not have a welder.

 

The stock intake is a cold air kit and deliveries more air than the motor could ever suck in, even with tunes/exhaust is flows more than is ever needed. On the 2valave motor a tuner doesn't add much if all in an increase in power, it does help with trans shift points and tq lock up so u think the motor is making more power but it's just the trans adjustments.

 

Any you suggest?

 

Gears and a Y-pipe..

 

Gears and a ypipe, transmission upgrade kit

 

The tugger trans valve body kit?? What brand gears is used most? I see people use 4.30s a lot. I plan on have a 4'' lift with 35'' tires.

 

The tuner does give lower trans temps and overall after exhaust and 75mm tb it is hard to get by with out a program I was running lean prior to the program. seems like quite a bit of power and I am no longer running lean also with a new fuel pump I noticed a considerable change I can smoke the tires at will now so I can not say a complete waste of money. The intake ram air at the grille is very restrictive I have also opened than up I have tried the k&N but went back to fram and a new MAF sensor. I am going to 4.56 gears next. I am running 4:10s with 235/85r16 currently. I am using 5 stars 87 performance email-tune.

 

TransGo Performance Shift Kits E4OD-HD2 - Free Shipping on Orders Over $99 at Summit Racing

This is what I have, I also bought the extra steel shift valves because the kit only gives you one for the 1-2 shift because it's known to stick. I also pulled the trans and did the TQ mods that the kit come with

 

Nogo73 I'm not gonna argue with you over your truck but why do a larger throttle body and mass air? On a stock engine it wouldn't do anything especially on the 2valve 5.4 with its undersized intake that is the main problem for power on the motor. And you can spin tires, well yes I'd hope so you have 4.10 years with super skinny 30" tall stock tires. I'm stock engine with transgo transmission mods and 4.30 years sleigh a Detroit locker and I can chirp the tears from a dead stop, i can even drift my truck on dry payment if I hammer on her and I'm running 255/85r16 mud terrains. I had stock size 265/75r16 on the truck for a week while tracking down a shimmy at 70mph last summer and with the same mods I just listed I couldn't keep the 265's from not spinning, if I had 235 tires all I would do I smoke the rears up!

 

Project heres my personal experience with tires/gears on a 5.4. My F350 came with 3.73 why I have no idea but it did, I HATED IT! I didn't like it with stock 265/75r16 and I hated it more with 285/75r16 which isn't a big tire at all on these trucks. Even pulling my 16ft grizzly tracker during hunting season I felt the little boat, towing my dads 20' CC the truck downshifted all the time and I'm in NJ where it's FLAT TERRAIN. Then I was never going to lift the truck so I figured 4.30 years would be perfect and YES they made a nice difference, this is how the truck should have been from the factory. I know felt some tire grunt at a stop which I felt on other 5.4 trucks that have stock 4.10 years and the little 235 size tires. No longer did the truck downshift ever second towing my little duck boat or my dads 20 footer, and I could use 4wd high and not have the motor struggle and sound underpowered when field hunting geese and picking up 150 shell decoys. NOW 4.30 on the highway with a 255 or 285 tire I run is still low and I have no problem holding 10ish mph which is up from stock. If I were to stay at the 33" tire range I would consider 4.56 years because I know the rom at highway speeds would only be 200-300 higher and still not out of control plus I'd get even more low end grunt, SO I'm at the stage after owning the truck since it was brand new off the showroom floor and I'm doing a 4" lift kit with 35" tires and for right now I'm keeping the 4.30 gears, I don't tow my 10k dump trailer or 10k utility trailer so all that's left is my duck boat and my dads 20' CC and I know without having the lift or tires I'm not gonna like the 35's and 4.30 gears, I know other tow with this setup or smaller 4.10/3.73 gears and say it's fine but once I feel the lose of low end grunt I'll hate the motor/gear combo all over again. I'm gonna live with it for a while but that day will come and I'll order 4.88 gears and I'll install them one weekend this summer. Then again I'll be happy with motor/gear/tire combo but I'll be about $600 in the hole for New Years and install kits

 

What gear size would be better for a 4'' with 35s, right now I dont tow, however, I will be towing in the future- small 7x12 enclosed trailer.