I have a 97' F-250 460efi supercab short box, that supposedly belonged to the state of SD. I bought it from a dealer that said it was from SD and it is in good shape, so I bought it about a year ago. I geuss I just never noticed it untill now but when I power brake it, it wont spin the tires, it is only moteraly quik from about 0-30 untill it shifts into 2nd then it is a dog. From about 30 to 95 it is so slow that it is almost funny. I have done no modifications but you would think somthing that gets 8mpg would have a little more go to it, or at least I think so. Is this normal for stock and what quick cheap things can I do to free up some power.

 

I had a similar problem on my '97 F350, same motor, it would bog pretty bad when under a load or when trying to accelerate fast. When it bogged, the engine sounded really choked up like it had something really restricting the air flow in the exhaust.
I took a look inside the catylitic converter and that was the problem. there was all kinds of buildup and crap from the engine that accumulated over a long time. So i replaced that with a new aftermarket cat, and while i was at it threw on a Flowmaster cat-back system and that helped a ton. Now my truck pulls better than ever, even up big hills pulling a trailer and carrying a big load. it has great response and gets up to speed pretty quick with no hesitation

 

thanks I might just take mine off then because it acts the same. It is not required to have one here but the other thing i guess is how much back pressure do i need?

 

you need some!!! I never took my cat off but when i took the stock muffler off..And had just the cat on i know there wasn't enoigh back pressure becsue it fell on its face at certain rpm ranges....

 

oh ok I suppose i wont straight pipe it then. thanks

 

look at your oxygen sensors... if theyre 1 or 2 wire youll need backpressure, if theyre 3 or more theyre self-heated and dont need backpressure.

 

dont worry about back pressure if your leaving your stock exhaust in, get rid of your cat and replace the stock muffler with a flowmaster. Those are cheap fixes. a expensive power gain would be long tube headers and cold air intake, and a chip. You may also want to look into your engines tune up status, it may be time to get in there, and change plugs, wires, distributor cap, filters, ect...