Recently I installed a Flowmaster cat-back muffler system on my 1992 F-150 4x4 Extended Cab, with a 5.8L (351 ci ) engine and a 3.55 rear axle. Previously I had installed a Superchip, with a K&N air filter. All were installed with the intent to improve engine performance when pulling a 5000lb travel trailer. There certainly has been a noticeable improvement, however I am now considering taking a final step by installing a new set of headers. According to some people I spoken to, they are suggesting that by installing a new set of headers, I will get significantly more performance from the truck and really make the towing of the trailer a breeze. While I hear this, I have also heard that by doing this I really won't improve the performance much, in fact, may reduce my towing capability. Who's doing the zooming? Appreciate some advice from the knowledgeable crowd, know some of you guys have done lots of this stuff and can set me straight. If headers are the way to go, which ones performs the best? Thanks,
-JP

 

Jpitura, I would consult mike (from superchips) about this. He's very knowledeable. Just my 2 cents, but often times if you open up the exhaust, and reduce bacj pressure too much, you will decrease your low rpm torque. Exactly what you don't want with towing. Actually you don't lose torque, you just move the entire powerband up to a higher level. That might be great for racing, but with towing you need all the low end you can get. Again try to consult with Mike.

 

Thanks, appreciate the advice. Thinking about what you have said, makes sense. Even with a cat-back exhaust mod (Flowmaster system), I feel a slight loss of torque, although they told me I would'nt. It may be that playing with the exhaust to improve towing ability isn't the way to go. Thanks again.
JP

 

In my 2000 F150 I changed my stock muffler for a 3" K&N cat back and right away I noticed the loss of torque at low rpms. Then I traded that truck for a 2001 SuperCrew and change only the muffler and kept my 2.5" pipes. With this setup I noticed a "gain" in low rpm torque!!
BTW, both trucks have the 5.4 engine.

 

Which muffler did you go with?

 

I went with the Magnaflow. It is loud enough at low speeds and quiter enough on the fwy to please my wife.

 

get long tube headers... they will keep more torque down low then shorty's