Adam_Ooh89

Hey guys, I own a 2006 automatic 4.0. It's got a few mods on it, but nothing too serious:

K&N CAI, AIRAID T.B.S., CATBACK EXHAUST w/ 2.5in PIPES, and a 91-octane race tune from the SCT/XF3 tuner.

According to fords specs for 2006 v6 mustang it produces 210hp with 240lbs of torque from the factory. I just recently had MY 2006 v6 dyno'ed and it only produced 205hp with 200-something lbs of torque (torque converter wasn't reading right or something).

...So, what the hell lol? After all of these mods I've put on I lose 5hp? I know there's more behind it so I'm looking for some more experienced/professional answers and advice.

Antonio323

Ford's numbers are at the crank. Dyno numbers are at the wheels. As the power is transferred from the engine through the transmission and through the wheels, it loses power. Automatics lose more power than manuals. A stock 4.0 has bhp of 210 and torque at 240. Those numbers at the wheels would probably be around 175 rwhp and 190 torque. Your mods are known to add around 20 horsepower to a 4.0 V6, so it looks like everything's good there. Where in Cali are you?

SKAR

/\

That, with an auto you (used to be anyways) expected to lose up to I think 15%.

Car companys advertise bhp, scroll way down to it

http://en.wikipedia.org/wiki/Horsepower

Adam_Ooh89

That makes a lot more sense and definitely helps me keep my composure lol. Thank you!

My next investment(s) consist of:
3.73 gears
A nice traction-LOK
70mm throttle body
Under drive pulley kit

Any specific order you would recommend those in?

aaquib1992

Gears and tlok first, you could probably find an 8.8 rear end with all those for not too much more cost wise, and you'd have a much better rear end for future mods (instead of the 7.5 which can't handle any serious power).

Ditch the throttle body though, I've heard they cause problems and I've never seen anyone with any noticeable gains from one.

Tanner05

Yep look for a used 8.8 instead of building a 7.5.
You'll probably speed the same amount of money doing either.
I actually have an 8.8 for sale.

Nuke

IIRC, about 185 RWHP is average for the 4.0. In that case, you're doing pretty good at 205. 20 RWHP gain on the 4.0 with a CAI & tune is about the best you'd expect.

+1 that the aftermarket TB is useless, but if it's not causing you any problems, leave it alone.

iAerials

its physics man.

astentine

Get the 93 Race Tune from them, then you'll see 215! Yeah, you're right where you should be with those mods.

Nuke

From 205 RWHP with a 91 tune to 215 with a 93 tune? On the 4.0? I'll have what your smokin'. 2, maybe 4, RWHP improvement at best.