heres a question?
 

my friend just got a 07 expedition with the 5.4,3.73gears and 2wheel drive. sweet ride! has the new six speed transmission! very smooooth ! we decide to have some fun! i followed him across a long bridge here in the area , late at night its very empty! as i followed he punched it! well i did what any red blooded american would do and punched it , well the best i could do is keep up! thats it ! i say that because i have a k&n and dual exhaust and a edge! set on level 3, i am runnig 3.73 gears also. one would think that i should be able to out run the expedition? any thoughts on this would be apreciated! p.s. my engine is the 5.4. so we have the same motor,the same rear gears. his transmission is 6speed. mine is 4speed. his curb weight is 5800lb.:coffee:

It is the trans, this is exactly what the F150 lacks to be competitive in the marketplace. A six speed has a much better gear spread and as a result it keeps the engine in the powerband much better than a 4 speed could. Plus being a brand new design I would imagine that the processor is probably faster and the trans is better able to react to driver commands. Putting this trans in the F150 should be a no brainer for Ford. Are you listening Ford

seriously...all in that trans. i cannot believe why in the world ford doesnt put that trans in the f150. hopefully by the next resdeign they will. my g/f had an 05 ranger with the 4.0 and the 5 speed auto and man that thing could haul ass..even with 3.55 gears and 32" tires.

yup ! i agree!

yeah but i dont understand why i could not outrun him? i am modded, he was stock?

6 speed trans has gear ratios that keep engine in it's powerband far better than our 4 speed in the F150. Your mods probably add roughly 20 to 30flywheel horsepower I would guess and the trans in the Expy can more than compensate for this. To put it another way, your engine had to lug more than the engine in the Expy because he has a gear ratio more correct for the situation than you did.

Your tire/wheel combo cant help either though.

ok! starting to make sense! thanks! in other words i need to call ford 1st thing in the morning and order a six speed transmission for my truck! lol

yeah pretty much :beers: or get a S/C or turbo either way your screwed money wise :rolleyes:

yup! just the usual! i done modding and trying to reinvent the wheel! im waiting for the new f150, with 6.2 motor! or that interceptor concept is starting to look pretty good.

im almost positive the new F150's will come with a 6-speed auto since the new tundra's come with it, plus the new 6.2 will be sweet im sure:banana:

yeah your right ! i was reading were the redisign would make the truck weight less. and that cant hurt!

check it out!


http://www.autoblog.com/2007/01/22/6...or-next-f-150/

Also, why they are at it... give the F150 (all engines) a 6 speed manual! :rocker:

Hi.

A few things come to mind ...

Effective gear ratio (higher numerically) on the Expy - rear ratio x 6-speed 1st gear ratio. First on the F150 is taller and I think 2nd is too.

Quite possibly the 6-speed has a lower driveline loss than the 4-speed (which is approx ~30%).

Your 4X4 also has additional driveline losses over a 4x2.

And your rolling mass (wheels/rubber) is greater.

K&N nets you next to nothing in real terms, and depending on your dual exhaust config, you may actually be killing your low-end torque.

Also Expy's have far different PCM calibrations than F150's.

The 5.4 already has a broad torque curve so 'keeping it in the powerband' is less relevant as it would be for, say, a peaky ricer :).

Put just a custom tuner on that Expy & he will simply run away from you :lol:

Better not tell him that! LOL!