Exhaust question
 

I'm not quite sure if this is the right place to put this thread, but here goes. I drive a 1997 Ford F-150. It's got the supercab and the longbed, and that cool looking XLT under the name. However, none of that is relevant.

I recently removed the muffler and put in a straight pipe. It sounds like a truck now. However, my grandpa threw a fit. He said it sounded like crap, and that it's not going to run right now. Something about back pressure. I've had other people say the same thing about backpressure being needed.

So my question is this: Is it really going to hurt my truck to have a straight pipe on it? As far as back pressure goes, and gas mileage? Wouldn't the catolytic (SP?) convertor provide the necessary backpressure? Also, when putting the straight pipe on, I used inserts in the pipe that were flared on end, and smaller on the other end. The exhaust is a 2 1/2" - 3" pipe, and the insert I have inside the pipe has a part that is only 1 1/2" in diameter. OD or ID, I can't remember.

I can't answer your question, but I can almost guarantee that you'll get a better answer at some other forum.

Can a mod correct my thread title? I don't know why I mispelled exhaust.

The muffler does create some backpressure by using different chambers to create noise cancellation. Now, is this really going to affect your performance? Not really...Unless you replaced the manifolds, removed your cat converter, and changed your piping to 5 inch mandrel bent pipes... you're not going to see problems.

I personally removed the cat converter, and put in a 'free-flowing' type muffler on my car, along with 1 7/8" primaries, and the only difference I'm seeing is I'm running a little rich at low-end... so hum... yea, you'll lose about 2-3 ft*lb of torque in the low-end, but maybe gain 1-2 HP in the high-end since you have less restrictions.

You should worry more about getting pulled over and ticketed for illegal muffler.

And pissing people off whenever you have to drive at night.

Personally, I think removing/replacing the muffler on a car/truck to make it "sound more manly" is just stupid. But maybe that's because I'm used to seeing kids do it to dinky little Toyota Tercels and driving around the neighbourhood in low gear.…

Heh maybe that explains the most of it. I personally don't like the uber loud sound and have done as much as I can to keep it quiet while having the best possible airflow... it's still pretty loud, but the stereo goes louder...

I've been thinking about adding on a dual exhaust kit on my Town Car, one that would make it sound more like one of those 5.0 Mustangs. Don't ask why :)

There is this fruit who lives right across the street from me. He did something akin to this, thinking that he can make his toyota 4-banger sound like some powerful 8-cylinder engine. It sounds like crap, and is very annoying.

To the OP, I am not entirely sure about he answer to your original question, but I can assure you that when the cops are called for violation of noise ordinances, backpressure will be the least of your concerns.

I can't tell you how many idiots I have seen (and heard) moving down the road in their ratted out automatic Accords and Civics, with unpainted, ill-fitting body kits and those FUCKING FART CANS.......a fat man cutting the cheese sounds a whole lot better than those things.

Well, actually, it is still quieter than my g/f's father's GMC. He's got a 5.7 L V8 with twin straight pipes compared to my 4.7 L V8 with the single pipe. I've driven right next to police, and I can still drive in at night and my grandfather doesn't hear me coming.

However, it seems you've answered my question. Thanks.

Additionally, you could try PM-ing Zephyrin. He seems to be the resident car expert.

Yeah I know what you mean. These kids in their tiny cars with the @#$%ed up mufflers... it doesn't make the engine sound more powerful. It just makes it sound like it has something very, very wrong with it.

I'dd readily fight for that title, any day.