05 st too slow

[fordsthebest]

hi all first post on the forum. just bought an 05 st and put a lift on it and a set of 285/75/16 tires on it and the truck just seems like a dog no power or anything just seems like the truck can't get out of its own way. Im trying to get rid of my 95 powerstroke which i put 5in stacks on it intake chip and the works and i don't know if im not just use to this truck or what but what can i do to give it some more. oh and by the way if any one wants a powerstroke let me no lol

 

[brianjwilson]

Welcome to the forum.
What gears are in the axles? I'm going to guess 3.73, best case is 4.10's. Keep in mind you just went from 30" to 33" tires, plus added lots of rolling mass.
The thing needs a re-gear to regain some of it's "oomph". 4.56:1 would be ideal for 33" tires (the 4.0 SOHC likes to rev anyway). If you had 4.10 stock (I did), then re-gearing to 4.56 would bring the gearing just slightly lower than stock, should be perfect.
I run 4.88's and it's great, but the rpms are a little high on the freeway so my highway mileage suffers.
Also, a tuner (xcal 2 or 3) will help get some power and re-calibrate speedo and shifts if you desire, but normally the power comes at the cost of running higher octane fuel.

Oh and post some pictures. I'm assuming you used a Performance Accessories 3" body lift?

 

[JohnnyO]

A 285/75 is about a 33" tire. I had 32's on my old '05 Trac with 3.73 gears and it was a dog unless I put my boot into it.

 

[chewy4x4]

Wilson why 4.88's I was thinking 4.11's in my Sport would be enough with 33's. What is your reasoning for being lower?

 

[brianjwilson]

Mine came stock with 30" tires and 4.10 gears (How it should me in my opinion). I drove other sport tracs with 3.73 gears and they felt underpowered to me. So I installed my body lift and 33" tires, and the 4.10's just didn't have much oomph...?
Plus when driving in the soft sand, slow trail rides and such, I was worried about overheating the tranny. Honestly I love the 4.88's except on the freeway. I can put it in 4low and first gear and coast down about anything very slowly, no brakes. It will crawl up things no problem, lots of get-up from a stop, pulls well.
If you have 3.73's, you will hardly notice any change going to 4.10's. And that's a lot of money to spend for such little change. I would definitely go with 4.56's if I did it again.
I used 4.88's because I found a front diff with a locker already geared to 4.88 for a great price, and who knows maybe I'll run 35's some day and it will be perfect!

 

[chewy4x4]

Thanks Brian,
I think you may be right 4.56's may be the way to go may be 4.27's, I want to get better fuel mileage with a set of 33's. I will keep reaserching but you did turn me from 4.10's.

 

[brianjwilson]

Unfortunately there are no 4.27 or 4.30 gears for the front differential. It's not a standard d35 diff.

 

[chewy4x4]

Brian I am 2wd I just want to regear to have better power with the 33's and still have ok fuel econ.

 

[brianjwilson]

Oh I didn't even notice the 2wd part. 4.30's would be okay with 33's

 

[chewy4x4]

Great now I start looking for 4.27's for my explorer and noone makes them So now the question is 4.10's or 4.56's. Remember I have 31's right now and it might be a while before the 33's but I will get the 33's.

 

[brianjwilson]

Just wait until you get 33's.