So this weekend I did the Gotts mod and used the SCT tuner on my 08 SCREW. Big differnce at WOT. The shifts hit so hard now it jerks your head back. We will see how much better it can get when I put 91 octane in with the tune for it. I am in Cali so 91 oct is the highest they sell. Wish I was still in tx for that 93 oct but you take what you can get.

 

Who wrote your custom tunes?

 

Where'd you get the programmer and tunes from??????

Edit....
Now I remember......https://www.f150online.com/forums/20...xperience.html

 

No custom tunes. Just changed the gear ratio to 373 (have the tow package) and running the preloaded 87 octane program. Next tank of gas going to switch over to 91 octane and use that tune. Hope I get a little more power. Wish I had custom tunes to really unlock the power but all in good time. Spending all my money currently on skyjacker 6", Vrock recon 18's, and nitto trail grappler mt 35's. having it all installed next month. Then I can afford to do some other stuff.

 

You just changed your gearing TO 3.73's? If you are adding 35" tires, you are going to be hurting pretty quick in the gearing department. You should have gone to at least 4.10's, but most recommend 4.56's.

 

Funny you say that, I wondered the same thing. I asked around for a long time before I began this project and all said that as long as I had the tow package gears (373) that I would be fine. I know that a larger gear ratio will be better but a ton a people are running the same set up. 4.56, do you really need to go that high? Is it that much better than the 4.10's? I have a 2x4 screw and it will never see off road. Just for looks, I know its a disgrace but its what I have.

 

poor truck



I can't believe you wasted money on 3.73 gears when you needed 4.56 gears

 

The use of the truck (off-road/on-road) is irrelevant for the most part. Just imagine how hard it is to pedal a 10-speed up a hill when you start off in 10th gear, that's effectively what your truck has to do when you upped the tire size. The end result is poor acceleration, increased stress/wear on the rotating parts, and bad gas mileage. I'd invest the extra $400 for a gear swap if I were you before you burn up the tranny or any driveline components.

 

Rozell, are you saying you phyically swapped the gear for 3.73s or that you changed the ration in the tuner to match what your truck actually has?

 

Didnt waste anything, truck comes stock with 373 gears when you have the tow package.
I see how what I wrote is confusing. I just switched the setting on the tuner to match what my truck came with. It assumed I had 353's(I think thats the stock base line gearing). Thats makes more sense now

 

Truck already came stock with 373's, just which the programer to match gear ratio.

 

one of my trucks has 3.55 gears and a factory tow pacakge...






I'm also confused, you changed gear size on the programmer to match the stock tune????? that makes no sense at all

 

I too have 3.55s with the tow package but when my programmer defaults, it defaults to 3.73 and I have to correct it to 3.55. I am assuming his is defaulting to 3.55 and he has to correct it to 3.73(if that is what the truck rally has). OP, what does your door tag say for axle?

 

I called the dealer and had them run the vin# to give me the gear ratio and its 3.73. The tuner is set to 3.55 from SCT so I switched it to 3.73 to match what I have. What year and engine size do you have. Mine is 08 5.4l

Never mind I see its an 05 which I am guessing is a 4.6l?

 

what is your axle code??? it's on the door tag...