can anybody give me some input, I have a 2003 mustang gt, w/auto trans,
with the following mods-force II flowmasters, bbk shorties w h-pipe, accufab 75mm throttle body,diablo tuner w/custom tune, trickflow plenum, k&n cold air ind, 3.73 gears, 2400 rpm coverter, mickey street drag radials, under drive pulleys, I had the car on dyno and only registered 209 rwhp & 199 trq, it turned a 14.2 1/4 mile on the track. I believe the power is stuck somewhere in the mods or motor but cant figure out where, my understanding is the car has 260 hp stock and with the mods I should have around 350 hp any advice or direction would be greatly appreciated, the car has 16000 miles on it?????

 

260 at the flywheel usually with gts abour 225 to the tires....209 is very unusllly low! ESPECIALLY with all those bolt ons! you should have about 265-275 rwhp!! i dunno what the problem is, even horrible weather conditions, you should be running better

 

I can only figure that something is not steup right, the car sounds and feels great , hopefully somebody has experienced this before and knows a cure, I have only had the car 6 months and I hate to get rid of it. puzzzling!!!!
If you know any real motorheads please ask there opinions and advise thanks.

Jim

 

it wont put donw anywhere near that.

As for your problem, i would do the basics, new fuel filter, and plugs. Also who tuned the car?

 

I'm having the same problem I switched from the 70mm TB to 75mm and my ET went down to 14.7 at cecil this weekend. I'm not running boost as of yet but figured with the plenum and throttle body change it would help alittle. I'm gonna have to say all that air going in isn't being used the right way. So I would try changing the TB back to 70mm or to stock. Because the supercharger the 75mm is the way to go but then again I'm not a gear head at all. This is the first car I've ever owned that I wanted to get faster. My car ran 14.0 at the track with the diablo tune and gear change. Since I'm going with a power adder I hope to get big gains with the 75 mm TB and plenum. Maybe someone who is a good mech can give better advice or info on this matter.

 

Thanks for your response and I guess basics is always a good place to start, with the mods on the car what do you feel it should be putting down, I based my theory of 350 hp at the crank on the most conservative estimates provided with the mods I have, also are you familiar with the Diablo predator, it was tuned by a speed shop, but i do wonder if something could be set wrong.
Jim

 

Thanks for the input, when I had the throttle body put on I questioned if it might be to much but was told not at all, have you heard to the contrary from a mechanic
Thanks

 

Actually from some posts on here about SC installs.
MT#1CUSTOMER has alot to say about this stuff he seems to be right on with this. The throttle body may or may not be the prob but the thing to do is go back to test and tune and bring the stock TB and swap it out and see if it does anything. Also some guys on here can give better advice about the diablo since I run a very conservitive tune with mostly for firm shifts and traction control and speedo cal. I'm going to be taking the car for a dyno tune in the very near future.
But as far as your ET my car was on the dyno about 6 months ago and pulled 244 hp at the rear with superchips tune and CAI, X-pipe, underdrive pulley, and slp loudmouth installed. You should have alittle more power. Anyway good luck