I recently installed a Hooker Aero Chamber muffler on my 4.2. SI/SO in place of the stock muffler. I went with the Hooker for higher flow with some back pressure and possibly some more sound. A number of positive things resulted.

For one the exhaust sound picked up a notch, sounds "like" a stock 4.6 GT Mustang by comparison, no nuisance noise in the cab at any speed. A little on the quiet side but more volume than stock.

Two, the engine revs freely now. Prior to the muffler the engine would wheeze at the top of each gear. Shift points under normal cruising were exactly as in the owner's manual. Before muffler, 4th to 5th shift was at 45-50 MPH, could run it up higher but the acceleration rate really dropped off. After the muffler I accidently found myself cruising in 4th gear at 65 mph on the interestate, twice on the first day, because the engine was running effortlessly compared to the stock muffler. Acceleration has improved, I can leave from a stop in 2nd without sliping the clutch as before and I now only have to feather the gas pedal to maintain highway speeds.

Third, after one tank of 87 octane my mileage is up a little over 5%.

Other benefits are that the appearance of the truck is improved without that huge torpedo hanging under the bed and now I can show off the aluminum drive shaft that is in plain view.

I originally wanted a loud exhaust, but have to say I can't find anything negative about this mod. Has anyone else run one of these?


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2001 F150XL, 4.2L 5spd, Black Reg Cab, Styleside, 3.55:1, Hooker Aero Chamber #51204

[This message has been edited by F1504.2L (edited 02-06-2001).]

 

I'm thinking about a new muffler, sounds like this is a good one. I have a few questions. First, did you loose or gain low end power/torque? How much $? Where from? Thanks for the help!

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2000 Silver F-150 XL Sport
Reg. Cab, Reg. Bed, 4.2L V6, 5-speed, 4x2

mods:
Tailgate lock, Generic bedliner, coyboy antenna ball
285/75r16 BFG AT ko (33.1x11.4)
Sony CD player, Blaunpunkt 5.25" speakers
Crimeguard alarm, Power locks

future:
1" coil spring spacer
new rims

dreaming:
true dual exhaust with flowmasters
RCD 5" lift, 315/75r16 Yokahama Geolander MT(34.9x12.6)
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Never let your schooling interfere with your education --Mark Twain

 

I can't detect any low end torque loss. It feels like it may have picked up a little since I can launch from second gear now which is something that wasn't as easy with the stock exhaust. Price is $51 from Summit.

This is the first muffler change I have ever done that has offered more than just better sound.

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2001 F150XL, 4.2L 5spd, Black Reg Cab, Styleside, 3.55:1, Hooker Aero Chamber #51204