Frustrated in Texas!!

[88Racing]

You don't need to sell the whole wheel package:
http://forum.gopowerhungry.com/class...e-package.html

Just swap out the tires to 275/55r20's.
Not unless you still have your stock 18's rims+tires?

[Tuscany FTX]

Originally Posted by 88Racing

You don't need to sell the whole wheel package:
http://forum.gopowerhungry.com/class...e-package.html

Just swap out the tires to 275/55r20's.
Not unless you still have your stock 18's rims+tires?

HA!HA! I am still running 305/55/20's. I just bought new wheels and tires.
Thanks,

[Jackpine]

OK, your OEM tires and gears were the same as mine. With your NEW tires and rims, your effective GR is 3.59, so you've lost a bit there. According to the Gear Ratio calculator in Pegasus, you would need 3.86 gears to get back to a "stock" performance level and, something like 4.10 would probably be better, to counter the additional rotating mass and rolling resistance.

Now, why your custom tune should be less "peppy" than the canned one is a big puzzle. It's possible that Bill tuned it that way for a reason. He can probably adjust for more power though if you're willing to take the hit on economy. This is something you'll have to work out with him. About the only thing you could try would be to raise your max rpm to maybe 5600 (if it's not already there) and your 1-2 and 2-3 upshifts to about 5200. I'd leave the 3-4 upshift alone and I would NOT go any higher than those numbers.

Remember, this is a truck you're driving, not a dragster. It's really not designed for that kind of abuse.

- Jack

[cody994x4]

why are yall racing f150 4x4's? take him off-roading and see who 'wins' lol

the difference has got to be:
1.)aftermarket rim/tire weight....you are heavier than ur neighboor
2.) leveling kit...you are most likely less aerodynamic...his nose sits lower, you have more 'drag' on your setup
3.)same trannys? same shift points? same final drive ratio?

if u're trying to make ur 4x4 fast....start by re-gearing, then exhaust, then a turbo!

g/l

[Tuscany FTX]

Thanks for all the responses!

[88Racing]

Another thing.
Check your parking brake to make sure that ain't hanging up and causing extra friction/drag.

[Power Hungry]

I suspect that part of the performance loss is the fact that we have to put the camshaft timing profile back to stock for CAIs so they don't drone like hell.

As for the tires, we're looking at a difference of 22-24 rev/mile... not a horrible change. At least not like switching to 35's or something like that. The fact that his performance is *THAT* off leads me to thing there may be something else going on with the vehicle outside of what tuning will be able to improve. If he's getting only in the 12's for 0-60, something simply isn't right. Even a bone stock struck should be getting in the 8-9 second range.

Lee,

One thing I'm curious about... do you still have the stock airbox? If so, it would be interesting to see if it makes any difference in the way the truck performs. If not... then you don't.

I can restore the camshaft profile to see if that helps pick up the power that you lost but it may cause the airbox to drone. Let me know if that' something you'd like to try.

Take care.

[88Racing]

With the stock airbox now Bill will have to recalibrate your timing+AFR curves.

Peace!

[Jackpine]

You MAY want to look at the "Gotts" style mod for an intake. Bill does not have to change anything for this mod once he recalibrates your tunes for the "stock box". Everyone who's tried it seems to think it improves the way the engine performs, without any of the adverse effects of a commercial CAI. Here's a link to how I did mine: http://www.f150online.com/forums/art...04-2008-a.html

- Jack