the Ex needs more power!

[BenJammin74]

there is a certain stoplight near my house that is 2 lanes at the light but then immediately turns to 1 lane. I constantly get the ******* in the other lane that wants to get past me before the lane ends. I am tired of being pushed around in the Ex. I have a stock 2002 2wd. It is hampered by the 4.6 (which I chose for better mileage). I don't want or expect rubber shredding power and I also don't want to compromise the reliability of the transmission. I was thinking of maybe underdrive pulleys, electric fan, different rear end gear, maybe an intake or exhaust or both. I love my truck, and I take very good care of it. I want to do my research before I do anything to it. I am sure there are others out there who are frustrated by the lack of HP on the 4.6s. What is a good starting point, and logical progression of performance modifications? What is the stock HP/TQ rating for the 4.6 and actual measured wheel HP/TQ? any help is greatly appreciated.

 

[greg hazlett]

232/290 is what the factory claims if I remember correctly.

 

[BenJammin74]

anyone? HP gains from bolt ons, etc. need advice please

 

[green03]

What gear do you have now?
3:73 is a good all around ratio and would help your truck get into its powerband sooner. Then put a hypertech, diablosport or other programmer on the truck to fix the speedo and give you a better tune. I can also do a chip for you to take care of this stuff. The 4.6 also benefits from a higher shift point at WOT and revised shift points at part throttle. This will make your truck a whole lot more peppy without killing your gas mileage, if you do in town driving alot your mileage will improve with the lower gear....
Matt

 

[BenJammin74]

Thanks for the good info. I was thinking of doing a set of headers as well, along with true dual exhaust. Those shouldn't hurt mileage too much should they?

 

[jimboh247]

Usually, anything to improve airflow will improve MPG, if you remember to keep your foot out of it.

 

[Capri331]

I am looking into getting an Expedition and have plans of putting at least pullies and a cold air intake on it. I see MAC makes 75mm throttle bodies for them too. If a TB is installed does the chip need tweaked? I am planning to do a few things anyway because I am hoping to use the truck to haul a drag car on an open car trailer and maybe a pop up camper in the future.

 

[green03]

The throttle body won't help the low end much, but it would breathe a little better up top. The only consequence is that it may actually make the trans shift points at part throttle too early for the amount of throttle you are getting (correctible with dyno shop software only) but for the most part you won't really notice it. Your money would be better spent on a cat-back exhaust rather than a throttle body.

Just my 2 cents,
Matt

 

[Capri331]

If shift points are controlled via thottle position senson input then why would the shift points be lower?

 

[green03]

Because you are now letting more air into the engine for the same throttle position as before. At WOT it wouldn't be any different. It wouldn't be noticible to most drivers.

Matt

 

[2THWTR]

I recommend a cold air intake: AEM CAI

and exhaust: Gibson exhaust system

Performance will be noticeably improved! Just make sure to disconnect your battery during the CAI install so that the PCM (computer) will reset it's base line and learn the new and improved air flow more quickly.

 

[compedge]

I'm guessing hey 150@ Hickory Tree!!

Have a "sleeper" diesel that teaches lessons there on a regular basis.. the "X" not so much but we a supercharged setup maybe!!!

 

[toms89]

I really enjoy when people try that to me now.. Would love to see the expression on their face when I punch the throttle because no one expects a 3 ton expy to move that quickly.

As far as off the line acceleration I would say changing the rear gear ratio would be the best bang for your buck. Specially with a 2wd and if you have the 8.8 rear. But you may need to reprogram the ecu to take full advantage and readjust the shift points accordingly. It can hurt highway mileage somewhat but that depends on your driving style and speed.