Frustrated in Texas!!

[Tuscany FTX]

Here is the deal. My truck is a "Turd", and I can't figure out why. I have an 06 F150 4x4 that is a conversion thru Ford by Tuscany. When I bought the truck, I was immediately not happy with the POWER. The only performance Mods on the truck at the time was 20" wheels/tires,SI/DO exhaust, and a leveling kit. My next door neighbor has same truck except 05 and stock wheels/tires. His truck will SPANK mine. For example 0-60 he is in the low 9's, I was low 13's, but he had CAI,Gryphon w/ Custom Tunes by PHP. Since then I have put a Banks CAI, and the Gryphon with Custom Tunes by PHP. When I received the Gryphon w/ "Canned Tunes" the truck definetly drove a bit better, but 0-60 was still in the High 11's. So, I had hopes of when I received the "Custom Tunes" that the performance would improve more. "NOT". I received the "Custom Tunes" and got an Custom 87 Performance and Custom 87 Tow. The truck runs GREAT on the freeway, very smooth, but still NO POWER. The best 0-60 I can muster w/ Custom 87 Tow is a 12.8, which is LOWER than the canned tune 0-60. I am at a loss! The truck sounds like it is going to take off, but it just doesnt. Any help or advise would greatly be appreciated. I also posted this on the F150 forum so if you see it twice it is me. Thanks again.

[88Racing]

What gears do you have?
What gears does your neighbor have?
What size tires on those 20's?
Just some more info needed.
Peace!

[88Racing]

One more question: What motor and do both trucks have the same one?????

[Tuscany FTX]

To my knowledge we both have 3:73 gears. We both have 5.4l engines. The only known difference is he has 17" stock wheels,tires, and I have 305/55/20's. I now have the Nitto Trail Grapplers, but before I was running Toyo Open Country A/T's. Thanks 88 for looking into my prob!

[Tuscany FTX]

88! One more thing. It is like NIght and Day difference. I wouldn't be concerned if it was just a little bit, but it is drastic enough to make you think something has got to be wrong with my truck. When I floor it (WOT) it builds RPM and sounds great, but it is like it doesn't engage. Not that the tranny is slipping or anything because all feels smooth, but it just doesn't go. His puts you in the seat and easily leaves me by 5-6 truck links.

[shotgun]

Boy - that sounds like the torque converter isn't locking up.

Are you monitoring it on the Gryphon?

EDIT:
From page 9 of the manual

COM GEAR

Visual gear indicator: Current transmission gear and torque converter lockup state

[Jackpine]

Actually, I suspect your wheel/tire combination. I think your tires are MUCH bigger than your neighbor's, which reduces your effective gear ratio by a bunch. This is going to make your truck slow off the mark, unless you re-gear to compensate.

If you tell me what size tires your neighbor has, I'll be able to tell you the difference in your effective gear ratios.

AND, I would not expect the TC to lock up at all in a WOT 0-60 run. With that load, the TC is going to stay unlocked to provide torque multiplication.

- Jack

[88Racing]

I'm with Jack on the wheel size.
The stock OEM on the 20's is 275/55r20.
This is the same size as the stock OEM 18 tire once squish is taken in and accounted for.
Peace!

[Jackpine]

IF your OEM tires were 275/55/20s, you've reduced your effective gear ratio to 3.58. You've lost a bunch of "mechanical advantage" and your truck is going to be slow off the mark. Now you can spend more money and re-gear if you'd like your acceleration back.

- Jack

[shotgun]

Ooops - I failed to pay attention to the WOT part.

Sorry.