How Much Horsepower did i gain?

[usmc_mac84]

i got a 2003 mustang GT conv. about 34,000 miles, great condition , not a huge racer, there are tons of mustangs around my area (jacksonville, NC) so when i pull up to the light next to some cocky Marine with a mustang, i like to beat them naturally. I went to the track and ran approx. 14.4, (auto trans) that's w/ spare tire, speaker box w/ amp in the trunk. I added the SLP Loudmouth exhaust, BBK shorty Headers, 75mm Throttle Body, Throttle Body spacer, 80mm MAF Sensor, and a set of underdrive pulley's, any guesses on how much horsepower i gained, and time i cut off in the Quarter??

[SpectorV]

14.4 is about right on for your car, if it was a hardtop it would be a touch quicker. With your mods to date you should be about .2-.3 faster maybe (probably .2 ish) and probably gained about 20-25hp/15-20tq~ a dyno will tell you for sure but in that range so you should have went from 260/302 stock to around 280-285/317-320

Get it on the dyno to see~ but not all dynos are 100% accurate (well none are) the auto sucks about 19-21% from the flywheel numbers

[lowflyn]

With those mods I think you'd really benefit from a dynotune, especially with the larger MAF so you can get it dialed in properly with that throttle body.

[Herbstang]

Quote: Originally Posted by lowflyn With those mods I think you'd really benefit from a dynotune, especially with the larger MAF so you can get it dialed in properly with that throttle body.

Agreed !! A dynotune will from a good tuner will get every bit of HP from the motor

[Danger Dude]

As said above a tune is required for the MAF to really do anything and I am not sure a larger TB is going to do much if the intakes are stock the bottle neck is not in TB. As for the throttle body spacer it does nothing at all. Those are leftovers from the caburator days when fuel and air were mixed before the intakes. Today all the fuel is injected directly into the heads.

[rocknbronco]

A spacer is supposed to allow the air to enter more rapidly into the intake from what some manufactures are saying?????

[Danger Dude]

Quote: Originally Posted by rocknbronco A spacer is supposed to allow the air to enter more rapidly into the intake from what some manufactures are saying?????

That is just one of many great lies most aftermarket companies say. No I have been to more dynos and including mine and there is ZERO gain in TB Spacer on injected cars. The only way to actually have any difference in flow is increase the size or decrease the size of the intake runners a larger Throttle Body wont do much because maximum air velocity of the runners to the heads have not changed. Now some cars like the older fox bodies got improvement in air intake do to the restricted nature of the 1st generation fuel injection systems.