How much horsepower is my 1999 mustang gt making with these mods?

Bill's answer is about right.

You have to remember you have parasitic loss. The factory rating for 99-04 GT's was 260 hp. This is at the flywheel. When you dyno a car you get the RWHP rating. You must remember that you're losing a good bit of power through the transmission, rotation of the driveshaft, and turning of the rear gears.

Stock 99-04 GT's dyno'ed at 210-225 RWHP.

K&N CAI adds maybe 6 rwhp, TB/Plenum only helps with throttle response, no power gains there. 91 Octane tune is good for about 10 hp, don't be fooled, their site will say some crap like 25 hp but that's only when they run the car on a dyno and professionally tune the car. U/D pullies are good for 8 hp. The terrible thing about your catback is Flowmaster. Flowmasters barely flow better than the stock mufflers meaning maybe a 3hp gain. They sound great but don't produce good numbers. I run Flowmaster 40's on my 02 GT.

You should be putting around 250 hp to the rear's.

With those mods you should run around 13.7-13.9 in the 1/4.

This Site Might Help You.

RE:

How much horsepower is my 1999 mustang gt making with these mods?

24lb injectors, K&N CAI and filter, 75mm throttle body and plenum, sct 91 octane tune, steeda underdrive pulleys, 3 inch flowmaster exhaust system (not sure which series), stock headers.

If you could also give me a rough estimate at a 1/4 mile time would be great too with 3:73 gears, tremec...

1999 Mustang Gt Specs

99 Mustang Gt Specs

Oh i hate to answer these but...Don't ever rely on what they claim to give you. Its never accurate. Your car started out with 215hp at the crank. You can pretty much take away 15-20% loss through the drivetrain before it hits your tires. First off, with just a CAI, your running way to big of a T-Body. 70mm will be fine unless you have the plenum port matched. Even then, your not sucking in enough air to notice. You should have done a PI conversion (stock heads/cams/manifold) and saved yourself some money from those trick flows. You would have instantly gained 45hp and would have now been at factory 99-04 hp range. Then you add your other goodies to make it around 280hp at the crank. As you stand, i would say your most likely at around 240ish tops. If your running stock cams, having those heads are worthless. if the cam isn't opening up the valves enough for the extra flow from the head, then it was just a waste of money. Sorry dude. You want a real answer, spend the money and have it dyno tuned. You want speed, get yourself lower set of gears. go with anice set of 3.73 or 4.10 and you will have a hard time wiping off that smile. Trust me.

A full bolt-on New Edge GT will make around 245-255 HP *at the wheels* which is roughly 275-290 HP at the crank.

horsepower 1999 mustang gt making mods: https://suggests.im/e11/how-much-horsepower-is-my-...

well stock 99s will dyno at 210. i think with your mods you could be around 260. and in the qtr mile high 13s. only one way to find out. take it to the track