FAQ: The Exhaust Thread

Going to single pipe will change the resonant frequency of the system. A dual pipe set up is quieter because the smaller diameter tubes are tuned to a lower frequency. A single tube will be larger dia, higher resonant frequency. Unless you select a resonater that cancels this note, it will make a droning sound.

Here's an interesting approach to curing drone that I think would work, regardless of tube diameter or number of pipes:

http://www.silveradosierra.com/exhaust/exhaust-system-drone-let-s-get-rid-of-it-t12607.html

Good info there

I don't really like that idea. It seems really restrictive. Would rather go with one of those twin loop mufflers.

This is the closest to our engine that I could find with them.

That sounds surprisingly good for the lack of resonator. Always afraid of ending up with the raspy sound.

Ohh yeah...I sounds alright

Quote :

I don't really like that idea. It seems really restrictive.

Things aren't always what they seem. Because the J-pipe is filled with air, it doesn't restrict. The air acts like a wall. But since the wall is made of air, it's permitted to resonate with the rest of the air in the system. Effectively, it's like adding a customized length of tube to your exhaust without the restriction. This lowers the resonant frequency of the system.

The author replies:

"If you will carefully examine the photos, you'll notice that the chambers are not connected into the flow path of the exhaust gasses. They only affect the drone sound because they are tuned chambers, capped at the far end. To prove this point, the temperature of these chambers is CONSIDERABLY LESS than the pipe they are attached to. My Pontiac was modified way back in 2009, so this is a proven solution and has been adapted by Solo Performance and used in their exhaust systems, especially for the new Camaros.

It works and it doesn't hurt horsepower."

I checked at Solo-Performance to see if they were in fact using J-pipes on their Camaro exhaust kits. Looks like they are:

http://solo-performance.com/axle-back-with-j-camaro-convertiblkit

A customer writes this in their review:

"Prior to driving my car with any Solo product, Jeff took me for a ride in a car that had, I believe, a Solo cat-back on it with the j-pipes. While Jeff was driving it, I was thinking to myself that I just drove six hours for THIS?? It sounded nice but way quieter than I imagined it would be….on the INSIDE!. When I got out of the car and he did a couple of drive bys, I’m sure my jaw dropped. It’s just inconceivable to me how the sound can be so different between inside and outside of the car. That is the magic of the J-pipes."

"Jeff said the real dyno measures the increase by 12 hp if I’m not mistaken. The trade-off is if you want the nasty, (in a good way), raw, loud sound go with the axle back. We also compared the weight of the stock system vs. the Solo system and the Solo was almost half as heavy."

Ive seen that idea in the Subaru community before. Its just a resonant chamber tuned to a specific frequency like the resonators on air intakes.

AA wrote:

Quote :

I don't really like that idea. It seems really restrictive.

Things aren't always what they seem. Because the J-pipe is filled with air, it doesn't restrict. The air acts like a wall. But since the wall is made of air, it's permitted to resonate with the rest of the air in the system. Effectively, it's like adding a customized length of tube to your exhaust without the restriction. This lowers the resonant frequency of the system.

The author replies:

"If you will carefully examine the photos, you'll notice that the chambers are not connected into the flow path of the exhaust gasses. They only affect the drone sound because they are tuned chambers, capped at the far end. To prove this point, the temperature of these chambers is CONSIDERABLY LESS than the pipe they are attached to. My Pontiac was modified way back in 2009, so this is a proven solution and has been adapted by Solo Performance and used in their exhaust systems, especially for the new Camaros.

It works and it doesn't hurt horsepower."

I checked at Solo-Performance to see if they were in fact using J-pipes on their Camaro exhaust kits. Looks like they are:

http://solo-performance.com/axle-back-with-j-camaro-convertiblkit

A customer writes this in their review:

"Prior to driving my car with any Solo product, Jeff took me for a ride in a car that had, I believe, a Solo cat-back on it with the j-pipes. While Jeff was driving it, I was thinking to myself that I just drove six hours for THIS?? It sounded nice but way quieter than I imagined it would be….on the INSIDE!. When I got out of the car and he did a couple of drive bys, I’m sure my jaw dropped. It’s just inconceivable to me how the sound can be so different between inside and outside of the car. That is the magic of the J-pipes."

"Jeff said the real dyno measures the increase by 12 hp if I’m not mistaken. The trade-off is if you want the nasty, (in a good way), raw, loud sound go with the axle back. We also compared the weight of the stock system vs. the Solo system and the Solo was almost half as heavy."

I've seen this before, they sell mufflers like this on eBay they call them twin loop mufflers I wonder how 3in catted downpipe-3in piping-mid mounted flowmaster- twin loop out the back would sound?

h20man wrote:

I found one on YouTube but it was cammed

I think I might know that car lol

turtleman wrote:

h20man wrote:

I found one on YouTube but it was cammed

I think I might know that car lol

haha yeah it was your car sounds good btw

My buddy has solo exhaust on his g8. J pipes removed the droan that's I'll but impossible to design out when it switches between 4 and 8 cyl.  The science works, the real life works. I was always planning it on the riv to see about curing some of the 3800 drone.

That's understandable, the 4-8 cyl switch thing. I bet this was a big challenge to engineering when they told them "Exhaust needs to be silent when used with both 4 cyl and 8 cyl engines." I'm guessing here, but wouldn't it make more sense to tune for quiet 4 cyl operation, getting louder with all 8 cylinders active?

I think it was more the buzz and drone you get when going to 4 cyl. Then if thats killed, then when back to 8 it might be back or not sounding they way they wanted. The solo kit wasn't just for being loud, they wanted a specific tone, but to do it with both 4 and 8, well you essentially have to make a kit that gives the sound you want for 2 different cars. Designing good sounding exaust is hard enough when you don't have to worry about shuttind off half the cyl.

So just reassure myself before I start taking measurements and ordering piping there isn't a car with an exhaust setup similar to the riv that could possibly bolt up? I heard something about the Cadillac Seville exhaust being close but not sure

69GSColorado wrote:

robotennis61 wrote:

69GSColorado wrote:

The majority of my noise comes from the thin tube headers. I hear more noise from the front of the car than the back.

Don't get me wrong, my car is not as quiet as stock, but it's super quiet for a car with a performance exhaust. There is slight drone at fourth and low climbing a hill, but even then it's still not even as loud as my dad's Regal GSX with a 3" DP and a 2.5" catback with Magnaflow mufflers at regular cruising speeds.

At 60 mph and above you don't even hear my exhaust. That's what I love because I do a lot of highway driving. However, when you floor it, it's a different story  

It's definitely a very low tone with absolutely no rasp. I believe the bigger piping helps reduce rasp.

you dont have a sound bite do ya?

No unfortunately I don't at the moment but I could easily get one in a couple weeks when I get my car back. It's back at home with my Dad's shop. I just had a dual guage pod installed and fastened to my A pillar. After re-upholstery, I'm installing a boost guage and fuel pressure guage. It's going to be awesome!

So, about this sound bite now..  would love to hear idle and maybe some driving? Pretty please?

h20man wrote:

So just reassure myself before I start taking measurements and ordering piping there isn't a car with an exhaust setup similar to the riv that could possibly bolt up? I heard something about the Cadillac Seville exhaust being close but not sure

I believe there is someone with Park Avenue Ultra exhaust.

Yeah check the Park Ave...

Yep, 2004 Park Avenue Ultra, bolts right up, is stainless and seems to have some performance advantage. Abertj has this installed on his.

Part number 25749911 I found it listed for about $630 from one of the online GM parts houses, and seemed to still be available (although I didn't try to actually order it)


Albertj and I were chatting about it and here is what we said:

Quote :

It is the exhaust for the 2004 park ave ultra. In my opinion it flows better than stock, based on I noticed that a flat spot I had with the old exhaust, around 2500 rpm, is Gone.

I strongly suggest you ask your local gm dealer about the price to you. I would not be surprised if it was discounted in some way. GMPD price is OK but the shipping is silly priced and the chance for damage is high with all that handling. I would order it soon because the 2004 parts are going to disappear soon (next year).

Also about "stainless" well the exhaust is T409 which corrodes, just not as fast as carbon steel. It will last like the original. You should clean it then paint it with silver engine paint.

As for sound, the mufflers are bigger than original riv but fit. They J U S T Fit. As for sound, it is quiet like a library, well under 58 dB in the cabin, i'm happy.

[quote="al_roethlisberger"]
Yep, 2004 Park Avenue Ultra, bolts right up, is stainless and seems to have some performance advantage.  Abertj has this installed on his.  

Part number 25749911  I found it listed for about $630 from one of the online GM parts houses, and seemed to still be available (although I didn't try to actually order it)


Albertj and I were chatting about it and here is what we said:


[quote]

It is the exhaust for the 2004 park ave ultra. In my opinion it flows better than stock, based on I noticed that a flat spot I had with the old exhaust, around 2500 rpm, is Gone.



I strongly suggest you ask your local gm dealer about the price to you. I would not be surprised if it was discounted in some way. GMPD price is OK but the shipping is silly priced and the chance for damage is high with all that handling. I would order it soon because the 2004 parts are going to disappear soon (next year).

Also about "stainless" well the exhaust is T409 which corrodes, just not as fast as carbon steel. It will last like the original. You should clean it then paint it with silver engine paint.

As for sound, the mufflers are bigger than original riv but fit. They J U S T Fit. As for sound, it is quiet like a library, well under 58 dB in the cabin, i'm happy.

wonder what the pipe diameter is?

My Magnaflows just arrived! they are getting installed tomorrow first thing in the morning. I'll have pics and vids up right away. Basically what im doing is just installing the mufflers in the stock location, and then having a turn down welded directly to them eliminating the crazy bend and stock tips ( ugly in my opinion ). I'm gonna keep everything tucked up pretty good for a nice subdued look.

wanna hear them

The car is on the lift, apparently these are not Magnaflows, rather they are "Fullboar" which is a knockoff brand but essentially the same thing. no wonder they were so cheap.
This video actually shows the Full Boar out flowing the Magnaflows, not sure how...
https://www.youtube.com/watch?v=wxPIt-eoT3w

Not alot of light in this pic but the entire unit is flat black:

Video is here:
https://rivperformance.editboard.com/t6854p75-exhaust-sound-clips#168403

96_Juggernaut wrote:

Not alot of light in this pic but the entire unit is flat black:

Uh,you have a lift in yer garagi?