I currently have a 99' v6 mustang 5-speed that is stock and was hoping to make it a little more street worthy and fun. My goal is atleast 225hp to the wheels but I was hopeful for around 250hp to the wheels. Whats my best route to go to acheive these numbers as far as modifications go, BUT I dont want any forced induction or spray.

Here's some stuff that comes to mind.......

- Cold air Intake
- 3.73 gears (I know they wont increase hp, but help alot in acceleration)
- Underdrive pullies
- Larger Throttle Body
- Exhaust system (perhaps, X or H pipe with some flows)

 

plain and simple.....NOT GOING TO HAPPEN without forced induction or spray, UNLESS you are willing to spend a lot more money on a cam, ported upper and lower intakes, 4.2 stroker kit, full bolt ons, long tube headers, and some other stuff. Gears do NOTHING to horsepower, btw......even then, you wont get to 250. You might be able to get 225 though.

 

full bolt 6 with a stage 3 powerpack from SSM will put out 245ishRWHP ive seen it done, mine puts out a tad over 200

 

OK stock your car will have between 150-165 rwhp depending on the tranny, and a lot of secondary conditions.

A CAI will only net 2-3 rwhp, although, to some, they are key to N/A engines in the long run, and or show cars. My advice would be to get a K&N filter, remove the air silencer, and get some filter sealer to seal the filter to the intake so dirt doesn't get in behind it, and whla, you're done there.

U/D pullies are almost a waste for performance. The hp gains with them is peak hp, and doesn't spread across the power band. So what does this mean, better looking dynos, a little better top end, but no real accelleration gain. They'll net you around 5-8 rwhp, but the MPG gains do make them worth the price. They don't add much, but every little bit helps.

Gears and differential do nothing for hp, but can drastically increase performance in the 1/4 mile.

Larger throttle body is useless as your stock intake much be port matched, and even then it won't do squat because it's the cam that starts to hold you back at that point, well, the heads too.

Exhaust is always a great idea. It will have a noticble affect on performance, and while they will only net you about the same gains as a great CAI, and or OK U/D pullies, they can nicely increase off the line throttle responce, and the difference, while very small, can be noticed in the 1/4 mile. Done more for sound than performance though.

To get what you're looking at, get the exhaust, and gears, then look into a 6-8 psi vortec or procharger supercharger. They will not affect MPG as long as you keep your foot out the fire wall, and will drastically increase performance. Put it this way, get one of those and you'll be well over the 250 rwhp point getting the same MPG as you do now during normal driving.

 

F/I is your best bet and will most likely cost less then all the work your going to need done to get to 250 N/A at the wheels.

 

Of course I have thought about this idea of forced induction and adding a procharger or turbo but, I dont want the cost of having to replace alot of internal parts with forged internals to withstand the power produced.

 

Actually, as long as you stay around 6 psi, 8 psi maximum, and have it properly tuned, your internals will be OK. It's only once you get up into the 9 psi S/Cs, and or 6-8 PSI S/Cs with a fully ported intake system and upgraded cam that you have to start to worry about your internals. Stock sixer internals are good up to around 300-350 or so rwhp, and a 6 PSI s/c, or even an 8PSI s/c isn't gonna cause you to break that threshold.