Dual Exhaust Problems

[Swazo]

Those crush bends have to be adding a little resonance in the sound, IMO.

There is no reason not to just run high flow cats. You aren't gaining that much more, if anything by NOT running them. Ditch the 60's era glasspacks and replace them with straight pipes. 2 maggy cats and the mufflers you already have will sound great.

With that said, I just replaced my gutted cats on my F150 with 2 high flow magnaflow OBDII kosher cats and it sounds just as loud, but with a much better tone with NO rasp. Before, it almost sounded like it had nothing but straight pipes. Now it sounds damn refined, and it's still a tad loud.

To find the proper place for your x-pipe, I'd hose down the front 1/4 to 1/3 of the exhaust with any rattle can paint. Then, on jack stands or anyway you can get a good look at the exhaust... start 'er up and watch the paint start to sizzle off. The hottest area is where you'll want to put the x-pipe. Where they put it on your system is just waaaaay to far back to do any good.

 

[Harrry]

Also speaking from personal experience....adding high flow cats with mufflers will still be loud. The bad thing is the rasp will still exist. Which is what most of us want to get rid of.

 

[Swazo]

You've used 2 proper sized cats and still had rasp? onder:

If I can do it with an NA 2.5, turbo 3L and an NA 5.4.......... it can't be too hard. The glasspacks are going to ADD raspiness, where cats are going to muffle it.

I ran my truck around the block with NO cat-back system installed, and only the new cat-forward 304L stainless steel mandrel bent 2.5" w/ 2 magnaflow hi-flow cats and it was about as loud as my truck was with NO cats and a Summit racing SI/DO 'performance' muffler, only NO rasp. The maggy round mufflers just changed the sound to the sweeter end of the spectrum.

My NA setup on my CSVT was factory piping w/ MSDS headers & y-pipe, hi-flow cat, no resonator, and Maggy muffs in the rear. NO rasp

I changed my turbo 3L exhaust system around a bit! But that really doesn't apply here, it had a turbo in the mix that will change the overall exhaust sound.

 

[Harrry]

You've used 2 proper sized cats and still had rasp? onder:


My NA setup on my CSVT was factory piping w/ MSDS headers & y-pipe, hi-flow cat, no resonator, and Maggy muffs in the rear. NO rasp

I changed my turbo 3L exhaust system around a bit! But that really doesn't apply here, it had a turbo in the mix that will change the overall exhaust sound.

Without sounding rude...this is related to true dual exhaust, which is independently flow exhaust from each side. When merging exhaust occurs sound/pules will change. But here is the trick even though there is a x-pipe or h-pipe the rasp will still be present because the exhaust will still flowing independently.

I drove my car around with msds headers high flow cats, x-pipe and edelbrock mufflers. It rasped between 2-3k all the time and sounded like a weed whacker throughout all the rpms. In the end i put my resonators back on and it is dead quiet now. No rasp at all.

First i had no cats only magnaflow resonators and magnaflow mufflers. Then i installed a x-pipe and replaced the magnaflows with edlebrock mufflers. Then i took off my magnaflow resonators and installed high flow cats. Then after 1 month i finally reinstalled my resonators. Now you would think i am crazy for doing this. But i wanted to know the differences by experience on what does what to our cars exhaust. This is what i did on my true duals in over 6 months of owing it.

Right now it is perfect the way it is. Pricey no doubt but perfect.

 

[S2Knott]

You've used 2 proper sized cats and still had rasp? onder:


My NA setup on my CSVT was factory piping w/ MSDS headers & y-pipe, hi-flow cat, no resonator, and Maggy muffs in the rear. NO rasp

i must be missing out......

i have msds headers, stock y pipe, maggy cat, lou's resonator and 40 series flowmaster and my car is RASP CITY baby! i just dont really wanna put more money into the exhaust.

 

[Swazo]

Muffler size has a lot to do with it, along with the right sized cats. The longer they are, the more they muffle. You can still have a free flowing, very muffled system. Loud doesn't always mean more power.

It's not rocket science here, true duals or not. If you aren't putting enough on to muffle the engine, you'll see different results with different combos. longer hi-flow cats with longer straight through mufflers are still going to flow very well, and it's going to change how loud it is. Different brands of products will net different sounds. That can be the PITA aspect of picking the right cats, resonators or muffler combo. On F150 forums, there are a lot of people putting sound clips of exhaust combos. Maybe it's time for Contour owners to do the same. The duratec is such a sexy sounding engine, it would be cool to hear the different setups IMO.

 

[Swazo]

i must be missing out......

i have msds headers, stock y pipe, maggy cat, lou's resonator and 40 series flowmaster and my car is RASP CITY baby! i just dont really wanna put more money into the exhaust.

I'd think that it was the Flowmaster 40's. They're a chambered muffler that is designed to sound pretty throaty and pretty loud. They don't flow great, so there might be some resonance happening.

I lean to Magnaflow as they are generally pretty cheap (in the bigger picture), well made and free flowing designs. Lots of OBDII kosher cats, in lots of sizes. One important thing is I like their basic sound too.

 

[Harrry]

Muffler size has a lot to do with it, along with the right sized cats. The longer they are, the more they muffle. You can still have a free flowing, very muffled system. Loud doesn't always mean more power.

It's not rocket science here, true duals or not. If you aren't putting enough on to muffle the engine, you'll see different results with different combos. longer hi-flow cats with longer straight through mufflers are still going to flow very well, and it's going to change how loud it is. Different brands of products will net different sounds. That can be the PITA aspect of picking the right cats, resonators or muffler combo. On F150 forums, there are a lot of people putting sound clips of exhaust combos. Maybe it's time for Contour owners to do the same. The duratec is such a sexy sounding engine, it would be cool to hear the different setups IMO.

You must be new to ceg right :laugh:

Damn it swazo look at the sticky at the top.:crazy:
I didn't write out all that crap to be ignored. Also beans has added the sound clip section over in the performance section. There are some exhaust clips in the sticky too.

If you read through out this section you will see intense conversations about exhaust combo's.

 

[Swazo]

Yup, not into 2.5's :shrug: I'd expect to see exhaust sound clips to be...... oh, I don't know..... in the exhaust section?? (joking around)
If it's not at least a NA 3L, I generally won't read about it if it's Contour performance related.

The sticky at the top of your sound bite had a good tone, but lots-a-rasp. (Edit: I listened to a bunch of the sound clips, including Derek-XB's old CSVT's. I heard his exhaust inperson quite a few times, and it didn't sound raspy like it did in the video clip. So, I might be off by saying lots-o-rasp about your clip.) You can't just discount the fact that a proper sized mufflers alone could rid you of your rasp, or a better matched set of cats and muffs and you'd still have the same tone/sound. This idea holds true to any car, including Contours with true dual exhaust.

Think of suppressors for firearms, if it's too small it's not going to do it's job right.

 

[Harrry]

You can't just discount the fact that a proper sized mufflers alone could rid you of your rasp, or a better matched set of cats and muffs and you'd still have the same tone/sound. This idea holds true to any car, including Contours with true dual exhaust.

Think of suppressors for firearms, if it's too small it's not going to do it's job right.

http://www.contour.org/ceg-vb/showthread.php?t=32271

Have fun reading this for a bit

 

[Swazo]

Like I said in my previous post, a free flowing exhaust doesn't have to be loud. You can get a straight through Magnaflow muffler that is the size of a coffin, have it flow better than an Edelbrock, Flowmaster or any other baffled muffler half it's size and be damned quiet. Scaling back to gain volume/tone (if that's what you're looking for) but avoid rasp is the key. I don't know why you keep fighting that idea. When you have a combo put together that's not raspy, but has a killer tone, would be about where you would want to be performance wise too.

I kept tabs on that post even after I had contributed my info. Read up on Greg's posts, he makes some of the best points in that thread and why I didn't feel like I could add anything new to it.

 

[Harrry]

Like I said in my previous post, a free flowing exhaust doesn't have to be loud. .

Correct.

You can get a straight through Magnaflow muffler that is the size of a coffin, have it flow better than an Edelbrock, Flowmaster or any other baffled muffler half it's size and be damned quiet..

True, but high flow rates from mufflers isn't always good in some cases. Added only for default.

Scaling back to gain volume/tone (if that's what you're looking for) but avoid rasp is the key.

. Agreed, which is why i cahnged my exhaust around...12+ times :laugh:

I don't know why you keep fighting that idea. When you have a combo put together that's not raspy, but has a killer tone, would be about where you would want to be performance wise too..

I'm not fighting this idea, i just don't want rasp or drone while i drive. I'm an old man :laugh:. It's def not enjoyable for daily driving :crazy:

 

[Swazo]

I feel you on the rasp (or even some drone), I've been playing with my F150's exhaust for a bit now trying to get a sweet sounding exhaust from idle to WOT. I'm ready to buy 2 new mufflers to go at it again now that I have everything else where I want it :blackeye: