stangman08

i have a 98 gt and iv noticed its gottenpretty poochie all of a sudden. when i accelerate it does alright till about 100 then seems like it runs out of power, it takes me for ever to even hit 120. i recently added a KN air intake kite and flowmaster catback exhaust hoping to help my power increase. i idnt notice any difference at all with the two mods. i have no clue wats wrong with my stang, its puting a sham to v8 mustangs right now, of how slow its running...PLEASE HELP!

defconfire

It's a NPI GT. That could be your problem.


But you could check your plugs and fuel filter.

stangman08

NPI? iv replaced the spark plug wires and fuel filter not to long ago.

stangman08

NPI? iv replaced the spark plug wires and fuel filter not to long ago.

defconfire

Ok here I go,

The NPI stands of Non-Power Improved. In 1999 ford redesigned the 2 valve heads that went on the 4.6l v8.


All modular 2 valve engines before 1999 were NPI and they have a good chunk less hp than PI cars. Many people do PI head/Cam/Manifold swaps which will give you a good amount of power I am not sure exactally what the gain is but im sure someone can chime in and inform you.

The swap will also bump up your compression a few points so you will ususaly have to run 91 gas.

ZW99GT

It's just a 190rwhp car. You can't really expect much from it at high speeds. It wasnt built for 100mph roll races.

Perf_white_GT

my motor went from 190rwhp to 290rhwp with a good head / cam(s)
done right you can significantly increase the power of your car...

562cobra

4 valve swap ftw!

whiterabit998

oh and theres no way ur gonna notice a filter and muffler mod.. they dont add more than 1 hp if ur super lucky

lewistk

+1, the only difference after those 2 mods will be the sound