I just got a new Silverado and I have no idea what kind of exhaust to get.. I want a really low rumbly sound. I was wondering if I could get some suggestions.

I have a 1999 GMC Sierra (see the GMC Sierra Thread for pics) that I designed a true dual exhaust for. Flowmaster 50 series. There are more details in the thread with the pics.

The system is wonderful. It sounds perfect. Not too loud to be annoying, but just right. When you get on it hard, it pipes up a bit. Sounds very aggressive.

If cost is a concern, and a true dual system is out of the question, I cannot recommend anything else. My research on the Gibson or JBA system didn't give me what I wanted. I would not have been happy with anything less than the dual system I have on there now. As you will read in the other thread, I have plans for a Wipple charger when my 1959 Elky is done in a few months so the duals are a must for the additional breathing the engine will do.

I ALSO JUST GOT MY LT Z71 AND I PUT A CUSTOM EXHAUST ON IT. THE MUFFLERS THAT WERE USED ARE CALLED TURBO TUBES AND IT IS A TRUE DUAL SYSTEM. I HAD THE PIPES COME OUT AT EACH END OF THE BUMPER WITH 4" CHROME TIPS. I HAD THIS DONE AT A CUSTOM MUFFLER SHOP. I AM VERY PLEASED WITH THE SOUND OF THEM, THEY MAKE A NICE RUMBLING SOUND WHEN TAKING OFF AND WHEN YOU REALLY STEP ON THE GAS THE COME TO LIFE. HOPE THIS HELPS.

:bandit: :bandit: I got a single outlet, dual outlet 40 series flowmaster on my 2000 GMC Sierra with a 4.8 V-8 and it rumbles pretty good. A dual outlet flowmaster is good if you'd like to keep some of your back pressure.

Originally posted by XOTech
I have a 1999 GMC Sierra (see the GMC Sierra Thread for pics) that I designed a true dual exhaust for. Flowmaster 50 series. There are more details in the thread with the pics.

The system is wonderful. It sounds perfect. Not too loud to be annoying, but just right. When you get on it hard, it pipes up a bit. Sounds very aggressive.

If cost is a concern, and a true dual system is out of the question, I cannot recommend anything else. My research on the Gibson or JBA system didn't give me what I wanted. I would not have been happy with anything less than the dual system I have on there now. As you will read in the other thread, I have plans for a Wipple charger when my 1959 Elky is done in a few months so the duals are a must for the additional breathing the engine will do.

This is what I have, and I love it. Not sure what series, but it sounds great!

Might as well get some fart pipes!!!!!!!!!!!!!!!


Everyone else is!:flipa: :finger: :frog:

No Fart Cans for me.

A pair of Flow Masters and a specifically designed exhaust Dual system.

I am not too fond of the Import Rage and the use of Fart Cans.

BTW, my '99 is a Sierra 1500.

I have posted pictures of my truck somewhere in this Forum. I don't remember where.

I've got a 99 Z71, and went a pretty cheap route for what I think is a great sound. My local shop cut the muffelr and til pipe off, and put Y in it, 2.5 inch pipes back until the last 18-24 inches, depending on how loud you want it, and then put chrome 3.5 tips. some local guys go through a semi dealer and get 5 inch heavy chrome pipes, and it will raise the roof if you get on it . I live in the middle of no where, and at about 3500 rpms a person can hear it fro abotu a miel and a quarter. Just driving, or in town it has a low deep tone, that will draw attention. a few hundred is all it ran me.

Take care not to get too much of a free flowing exhaust on the new trucks.

The new vortecs seem to work best with a little backpressure, you could lose some low end torque opening it up too much.

If looking for loud noise.....Flowmaster 2 chamber 40 series or Dynomax Ultra Flow Welded Mufflers.

A nice rumble tone......Flowmaster 50 series or Thrush Turbo's

fyi>>> backpressure is bad.

you don't want it. people are using the terminology incorrectly... but the idea is right, you don't want restriction at all, you do want a little, not completely open on a street vehicle.

also...

no one here has a true dual setup unless you are running straight off the header/manifold into a separate cat and out into a separate muffler, which is hard to do on today's vehicles... i've been under those trucks, and it doesn't make sense to put two mufflers on it...

also...

www.corsaperf.com... nice kit there... expensive but sounds as good as the flowmaster setup if not better...

backpressure explanation, if you want to read it...

this isn't necessary to read, but will open some eyes...
not my post, but found from texan who used to post here...

A lot of people have different thoughts on backpressure, and often confuse it with Velocity and Delta Pressure...
I will now post a colaboration of posts from Purehonda.com

"THE MYTH OF BACKPRESSURE"

…is probably the most widely misunderstood concept in engine tuning. IMO, the reason this concept is so hard to get around lies in the engineering terms surrounding gas flow. Here's the most impotant ones you need to be aware of to understand the things I'm about to say:

BACKPRESSURE: Resistance to air flow; usually stated in inches H2O or PSI.
DELTA PRESSURE (aka delta P): Describes the pressure drop through a component and is the difference in pressure between two points.

One other concept needs to be covered too, and that's the idea of air pressure vs. velocity. When a moving air column picks up speed, one of the weird things that happens is it’s pressure drops. So remember through all this that the higher the air velocity for a given volume of gas, the lower it's internal pressure becomes. And remember throughout all of this that I’m no mechanical engineer, simply an enthusiast who done all the reading he can. I don’t claim that this information is the absolute truth, just that it makes sense in my eyes.

Ok, so as you can see, backpressure is actually defined as the resistance to flow. So how can backpressure help power production at any RPM? IT CAN'T. I think the reason people began to think that pressure was in important thing to have at low RPM is because of the term delta pressure. Delta pressure is what you need to produce good power at any RPM, which means that you need to have a pressure DROP when measuring pressures from the cylinder to the exhaust tract (the term "pressure" is what I think continually confuses things). The larger the delta P measurement is, the higher this pressure drop becomes. And as earlier stated, you can understand that this pressure drop means the exhaust gas velocity is increasing as it travels from the cylinder to the exhaust system. Put simply, the higher the delta P value, the faster the exhaust gasses end up traveling. So what does all this mean? It means that it's important to have gas velocity reach a certain point in order to have good power production at any RPM (traditional engine techs sited 240 ft/sec as the magic number, but this is likely outdated by now).

The effect of having larger exhaust pipe diameters (in the primary, secondary, collector and cat-back exhaust tubes) has a direct effect on gas velocity and therefore delta P (as well as backpressure levels). The larger the exhaust diameter, the slower the exhaust gasses end up going for a given amount of airflow. Now the ***** of all this tech is that one exhaust size will not work over a large RPM range, so we are left with trying to find the best compromise in sizing for good low RPM velocity without hindering higher RPM flow ability. It doesn't take a rocket scientist to understand that an engine flows a whole lot more air at 6000 RPM than at 1000 RPM, and so it also makes sense that one single pipe diameter isn't going to acheive optiaml gas velocity and pressure at both these RPM points, given the need to flow such varying volumes.

These concepts are why larger exhaust piping works well for high RPM power but hurts low RPM power; becuase is hurts gas velocity and therefore delta P at low RPM. At higher RPM however, the larger piping lets the engine breath well without having the exhuast gasses get bundled up in the system, which would produce high levels of backpressure and therefore hurt flow. Remember, managing airflow in engines is mainly about three things; maintaining laminar flow and good charge velocity, and doing both of those with varying volumes of air. Ok, so now that all this has been explained, let's cover one last concept (sorry this is getting so long, but it takes time to explain things in straight text!).

This last concept is why low velocity gas flow and backpressure hurt power production. Understand that during the exhaust stroke of a 4 stroke engine, it's not only important to get as much of the spent air/fuel mixture out of the chamber (to make room for the unburnt mixture in the intake system), it's also important that these exhaust gasses never turn around and start flowing back into the cylinder. Why would this happen? Because of valve overlap, that's why. At the end of the exhaust stroke, not only does the piston start moving back down the bore to ingest the fresh mixture, but the intake valve also opens to expose the fresh air charge to this event. In modern automotive 4 stroke engines valve overlap occurs at all RPM, so for a short period of time the exhaust system is open to these low pressure influences which can suck things back towards the cylinder. if the exhaust gas velocity is low and pressure is high in the system, this will make everything turn around and go the opposite direction it's supposed to. If these gasses reach the cylinder they will dilute the incoming mixture with unburnable gasses and take up valuable space within the combustion chamber, thus lowering power output (and potentially pushing the intake charge temp beyond the fuel’s knock resistance). So having good velocity and therefore low pressure in the system is absolutely imperative to good power production at any RPM, you just have to remember that these concepts are also dependent on total flow volume. The overall volume of flow is important because it is entirely possible to have both high velocity and high pressure in the system, if there is simply not enough exhaust piping to handle the needed airflow.

It’s all about finding a compromise to work at both high and low RPM on most cars, but that’s a bit beyond the scope of this post. All I am trying to show here is how the term backpressure is in reference to a bad exhaust system, not one that creates good low RPM torque. You can just as easily have backpressure at low RPM too, which would also hurt low RPM cylinder scavenging and increase the potential for gas reversion. And understand that these tuning concepts will also affect cam timing, though that is again probably beyond the scope of this post. At any rate, hope this helps, peace. "

-here's a reply to the above post-

"I've been seeing a resurgence of the backpressure misnomer, but didn't have the time or inclination to write it up. So, again, thanks.

There is one thing I'd like to add to texan's work:
Exhaust Scavenging
In essence, this is the opposite of the exhaust reversion that texan describes.

Reversion: at the beginning of the intake stroke during cam overlap, exaust gas in the header is under high pressure (negative delta P) and is pushed back into the cylinder, diluting the new air/fuel charge.

Scavenging: at the beginning of the intake stroke during cam overlap, the momentum of the exiting exhaust gasses creates a brief vacuum (positive delta P) in the header, pulling out the remaining exhaust gases from the combustion chamber, and allowing the new air/fuel charge to be full-strength.

Scavenging is also the reason for differently shaped headers (4-2-1, 4-1) and collectors. We use the momentum of exiting exhaust from one cylinder to scavenge exhaust from another that is next in the firing order! The different shapes allow for this to happen at different airflow velocities thus at different RPM bands.

Scavenging takes advantage of the momentum of the exiting gasses. In essence, the fast moving exhaust pulse pulls a vacuum behind it. Momentum is mass times velocity. So not only do we need to keep the velocity high to prevent reversion - but it greatly improves the scavenging effect.

Thus we have a balancing act (as others have pointed out). We want to minimize friction to lower the backpressure as much as possible - larger pipes have less friction because they have less surface area per unit volume. But we want to increase the delta P as much as possible to prevent reversion and increase scavenging effects - smaller pipes increase delta P because they increase velocity.

There are lots of tricks to try to widen the useful RPM band (stepped headers) or to increase the overall effiency (ceramic coated exhausts), but it's still subject to this basic tradeoff:
Friction vs. Velocity
AKA: Backpressure vs. Delta Pressure
You want low friction and high velocity.
You want low backpressure and high positive delta pressure.

I can't believe you posted that long ass thread on backpressure.:rolleyes:

it's worth posting...

alot of people have an idea of what they're talking about, but don't know what the words mean...

that's why i like to clarify

sorry...

The lack of backpressure does have some effect on torque during your lower to mid-range rpm's. At least that is what some professionals have told me.:bandit:

did you read that at all?

back pressure is not what people say it is... it's used incorrectly...

you are right, as there is some "restriction" necessary on a street motor...

read what that long ass post says and you'll understand what i'm saying

Fly,
Excellent post on exhaust. Well collected comments about some of what goes on in the exhaust cycles of engines.

As one would guess, every engine is slightly different in what works best based on cam, valve overlap, duration, etc. as well as exhaust size, even the number of sharp bends in the system, duals or not, etc.

As for the system on my 99 GMC, I assure you it is a "True Dual" system. At that time, there were no true dual systems out. Having done the research on the new LS1 and what it would take to wake it up some and what mods would benefit the most in the immediate and in the longer term goals I have for the truck, the exhaust was an absolute must. My results have proven I made the correct choice and properly executed the design.

To throw a further complication to the exhaust design, I have designed the system to be more accurately optimized with the supercharger that will soon be installed. Meanwhile, the benefits of the True Dual system and larger diameter tubes have been worth the effort. As one last point, to complete my truck in anticipation of the the supercharger, I have also planned for the use of Long Tube Headers.

I'm looking for a cat-back exhaust system that comes out split rear. But it seems that the only way to do that is by removing the spare tire. Are there any systems out there that you don't have to remove the spare tire for a 5.3L short bed silverado?

I'm looking for a cat-back exhaust system that comes out split rear. But it seems that the only way to do that is by removing the spare tire. Are there any systems out there that you don't have to remove the spare tire for a 5.3L short bed silverado?
Did you check Gibson Exhausts?

Hey Tommo, Screw all this backpressure BS. Throw some Cherry Bombs on it or If you want the rumble go with Dynomax. :)

yeah i checked gibson. i'm pretty sure that if you want the split rear exhaust you have to remove the spare w/ gibson.

That really sucks. I love the sound of performance exhausts, but don't like all the work involved in getting the type of exhaust you want. I did my car the most inexpensive way and easiest way posible. :D

Daniel,
Since I designed my system from scratch and not really caring what other vendors had already made, I am not certain what is available, but I would suspect that someone does make a system that does not require the removal of your spare tire. I designed my system such that I didn't have to remove the spare.

Some of the systems I briefly looked into before deciding to go completely custom... Jardine / Basanni (sp?) / Borla. You might try them.

In fact, I remember going for a ride in a truck with a Jardine system in it. I liked the sound, and the quality, but not true dual.

I have had different mufflers on many of my previous vehicles and have compared to others that are available. I continually come back to the same answer... FlowMaster. I don't care for DynoMax or many of the others, and definitely no Cherry Bombs for me.
I could not be more pleased with my system, the sound, and the improvement. It is just quiet enough to not be annoying and loud when I want it to be.

Then again, I ran the truck with open exhaust for several days as we sorted out the issues with the true dual system as we built it. It was fun with open exhaust. A little too bubbly, but sounded great when you got on it.

. It was fun with open exhaust

Oh yeah, I love comming up on Mustangs with duel exhausts and they see me pull up. They be thinking nothing untill I hit the gas. It will make your ears pop sometimes while driving.:D

Does anyone have any recommendations for en exhaust that is on the quiet side. I drove a modified mustang for years and I'm really sick of hearing the exhaust. I just want something with a little bit of a power gain and still quiet. Any recomendations?

Dynomax Turbo Mufflers are pretty quiet. They make a good sound though.

mdrz71, reread my previous post about my system. I wanted something that was reasonably quiet most of the time with only an indication that there was something not stock about it. I chose the Flowmaster 50 Series. It is a great compromise for quietness when you are not hard on the throttle, but they do pipe up when you get on it. They sound agressive when you want them to, but are liveable for everyday driving. I would make the same choice again without question. The open exhaust was fun for a day, but highly unpractical for me. I do not find it impressive or "cool" to have nearly open header Mustang sound all the time. There is a time and a place for it, but on the street, I feel that is a bit too agressive and often very annoying.

Hope that helps.

Thanks for the info. I have heard the Magna Flow was quiet. Anyone heard anything? I hadn't ever heard of flowmasters being quiet but maybe that 50 series is a new muffler. Did the exhaust make a justifiable difference in power? I'm happy to have a quiet ride after years of having to yell in my stang.

Series 50 is a little more mild than the Series 40. I did notice a power and torque gain because I redesigned the whole exhaust system to be a true duals. I highly doubt that you would notice a power increase from just installing new mufflers. You will like the sound, but there are many more mods required to realize substantial power gains.

I am not as fond of the MagnaFlows, but it is a matter of taste. Up to you.

Originally posted by DanielMcA
I'm looking for a cat-back exhaust system that comes out split rear. But it seems that the only way to do that is by removing the spare tire. Are there any systems out there that you don't have to remove the spare tire for a 5.3L short bed silverado?
http://www.borla.com/ ;) very good cat-backs there. i dont know if they're cheap in price, but id think so.

most systems have to remove/relocate the spare b/c of the tight space constraints...

the split rear set up goes up over the axle, then splits to the driver's side, right behind the axle, right in the area occupied by the spare tire... which is why it won't work... too tight of a fit...

Good observation Fly,

That is a typical problem of most vendor kits. Yet another reason why I chose to design my own system. I did not have to relocate my spare tire. I don't believe there are any vendor kits that allow for the spare tire to remain in its original position.

yeah...

the reason for that is that there are too many variables to produce a kit that will fit allllllll the different vehicles, depending on things like the size of the spare, etc...

most of the time, those kits could fit, but are too tight, which is why your custom kit works great, b/c it's made specific to what's under your truck...

I just installed a magnaflo cat backsystem in my 2000 5.3 Z71. 3" stainless, polished tip, looks great and sounds even better. Absolutely the best fitting bolt on anything I've ever delt with. Very happy with the sound outside and inside the cab. My :2cents:

correct me if im wrong, dont all of these trucks(mines a'00 3-door sierra) come with separate cats that go thru a d/i-d/o muffler? my 2 chamber flowmasters sound awesome(200k miles on them) but about 50k or so miles ago,i started noticing various rattles coming from what i thought was the duals vibrating against the truck. i've got it isolated to what sounds like chunks of metal rattling around inside the mufflers themselves. could it be pieces of the cats, or mufflers themselves breakin up? i havent had time to take it back to exhaust place yet.. a simple fix i hope

I have an '05 Silverado with the 5.3 liter. I went with the Magnaflow. I had heard many posts about others rusting out prematurely, so stainless was a big item for me. The Magnaflow was the perfect install. I installed myself and everything fit perfectly.

The sound, ahhhh, the sound.. Deep and at wide open throttle, you really notice the difference and appreciate the quality.

Beware, there is some resonance, so you may want to insulate the cab with Dynamat or something similar. My Polks and Infinity Basslink minimized that, but still need some deadoning.

For my money, you can't go wrong with the MagnoFlow, the tips look great too.

I just did a Volant cold air kit today with the ram air option. Noticable improvement. Next on the list, is the performance chips and tuners. Not sure which one yet, perhaps the Diablo.

Good Luck

My son put a Gibson single 3" system on his '04 Silverado Z71, plus a K & N FIPK intake system. The combination sounds awesome. In the cab, his FIPK growls from under the hood exactly like the real headers on my '90 383 Suburban.

go with a nelson tune

whatever you get make sure its single in and dual out especially with the flowmasters it has a louder but lower rumble......and i think its the sound yousomewhat described that you want.

Little disheartened with the Magnaflow I put on my truck. Nice deep low grumbly sound but, at 1500-2000 RPM the Resonance in the cab is really annoying. I'm actually thinking about taking it off and putting the stock exhaust back on.

Maybe I'll just take the stock one and have some dual pipes welded out the back.

Guys, this thread goes way back to 2001. Let it go.

Mod, lock it.

If you want a simple system but great sounding exhaust. Cut the muffler out. DONE!!!
You get the nice low grumble when you accelerate, but not too loud when idle. But when you smash the accelerator, everyone will know you are comming :D
The best part, is that you can do it yourself if you wish or you can pay about $200 to have someone cut the exhaust out and run a a 4" pipe to the side like what I did.

Go with MagnaFlow, they have the best sound - not like a wanna-be yuppy that just wants NOISE !

Stay away from Gibson, rust out too fast....