One solution that appeals to truck owners who only require additional exhaust flow in specific situations is to install an exhaust system cutout. A cutout is essentially a Y-pipe that is welded inline with your existing exhaust piping. At its most basic, a cutout is designed so that the portion of the Y-pipe that vents to the atmosphere can be opened in order to divert exhaust gases and bypass a vehicle’s mufflers and resonators. In theory, this creates an exhaust system whose only restrictions are the catalytic converters, which increases flow, reduces back pressure and generates more power.

The QTP exhaust cut-out system explained. Click on the image to see QTP's website.

Quick Time Performance has an electric cutout system that is a little bit fancier than the design described above. While the QTP setup also consists of a Y-pipe, it additionally provides full remote electronic control from inside the cabin over how much the Y-pipe is opened. The system can be set to open fully or in small increments, which according to the company allows you to vary your truck’s exhaust backpressure to suit your application. At the touch of a button, any Tundra equipped with Quick Time Performance cutouts can go from a mild to wild exhaust in a few seconds.

QTP Cutout and Controller

There are obvious advantages to using an electric exhaust cutout. If you are someone who frequently drives off-road where the amount of noise your truck produces is really only limited by your own personal tolerance, then the appeal of a QTP cutout system is obvious. The same can be said for anyone who takes their truck to the drag strip, where opening up the exhaust for a quick 14 second pass down the quarter mile could also be beneficial.

That being said, there are a few issues with exhaust cutouts that should be kept in mind. Although Quick Time Performance claims that the reduced backpressure provided by an open cutout actually improves fuel mileage, this claim isn’t backed up by any real-world testing. In fact, it would not be surprising if the reason that trucks running open cutouts used less fuel is because their drivers go easier on the gas pedal in order to save their hearing – and their sanity.

QTP Dual Cutouts

Perhaps more importantly, for anyone who lives in a northern climate where road salt is a fact of life, cutouts remain extremely vulnerable to corrosion. While portions of the QTP setup are made out of aluminum, there are still a number of steel components – including the butterfly plate – that could rust up and eventually seize in either the open or closed position.

Quick Time Performance cutouts are a viable solution for those who need to occasionally bypass their exhaust system for trail driving or drag racing, and who are aware of what they will be getting into in terms of noise and potential corrosion risks. However, few outside of this particular group of Toyota Tundra owners will actually benefit enough from installing exhaust cutouts to outweigh the noise, complexity, and corrosion risks that go along with them.

Check out this list of available Toyota Tundra shocks

Gibson Exhaust offers aluminized and stainless steel cat-back exhaust systems with single pipes – either rear or side exit – as well as dual pipes with rear or side exits. Pricing starts at about $450 including shipping.

Gibson Performance Exhaust is a bit of an oddball company in the sense that the founders began their exhaust work while looking for a way to improve the performance of their motorhome. Not many people would think to parlay a venture involving Winnebagos into a full-fledged sport exhaust empire, but the Gibson family did and today they are one of the larger exhaust companies operating in the United States. For the Tundra, a cat-back system is available that Gibson claims will increase horsepower between 10 and 15%, while providing a torque boost of 15-20 lb-ft. The term ‘cat-back’ refers to an exhaust system which bolts onto the stock system behind the catalytic converters, maintaining the factory emissions controls, but replacing the stock mufflers and resonators. The extra power from the stainless steel Gibson exhaust comes from the less restrictive mufflers and mandrel-bent piping, which maintains the same pipe diameter without any crimping in the curves.

Flowmaster offers an aluminized steel American Thunder dual exhaust system that can either be configured to exit at the rear or on the side. Pricing starts at about $650 including shipping.

Flowmaster is a name long associated with performance vehicles. The company got its start in 1983 quieting down the engines of Sprint Car racers in order to meet local noise ordinances, and this racing experience has been carried over into their street applications. Flowmaster makes a complete cat-back system for the Tundra that is supposed to improve fuel economy and increase acceleration through greater exhaust gas flow. Interestingly, the company does not make any specific claims regarding power increases.

Borla offers a complete stainless steel cat-back exhaust system. It’s top quality, but it’s also top dollar – pricing starts at $1,000.

Borla is a well known name in the world of exhaust, and they have a long line of products that finds itself used on some of the most potent exotics and sports cars in the world. The company’s original focus was the design and installation of custom exhaust systems on rare European vehicles. Today, they have a wider range of offerings that even covers the Tundra. In fact, Borla has two cat-back systems designed for the Tundra, one with dual side-exit exhaust and one with dual rear-exit. Like Flowmaster, they don’t make any specific power claims, but the price is substantially higher than either of the other two companies we have so far discussed.

Magnaflow cat-back exhausts are available on the Tundra in either a dual rear exit or a single side exit configuration. Starting at less than $500 (including shipping), Magnaflow exhausts are very affordable and, along with Gibson exhausts, they’re an excellent option.

Magnaflow is well known for their stock muffler replacements and performance muffler options, but Magnaflow also makes a complete cat-back exhaust for the Tundra. In fact, they have 3 – one with a single side exit, similar to stock, one with a dual side exit but on the same side, which is unique amongst the companies we have examined, and one which is a dual exit at the rear. While Magnaflow claims that horsepower and torque are increased by their system, they decline to list an exact figure. One of the most interesting aspects of the Magnaflow website is the page where you can actually hear a sound clip of what the exhaust will sound like on your truck. While the Tundra sound clips only include the 4.7L, they promise more sound clips in the future.

Learn more about why you should consider buying an after market exhaust, the differences between single and dual exhausts, and listen to some Tundra exhaust system sound clips.

Check out this list of available Toyota Tundra shocks

Thanks for the great info regarding the Tundra 5.7L exhaust. I have a question though. The local muffler shops offer dual in dual out exhaust for the Tundra, but they use smaller crush bent 2.25″ pipes for the exhaust. Will the smaller pipes hurt the performance of my truck or break even with the OEM 3″ exhaust? I want the dual exhaust sound, but not at the expense of performance, so should I just replace the stock muffler and keep the stock single 3″ exhaust pipe or dual it out with a couple of smaller 2.25″ pipes?

Good question.

Most muffler shops will tell you that pipe size isn’t nearly as important as pipe configuration and layout, but I don’t see any reason why you can’t have both. Smaller pipes increase back pressure, but that can be alleviated somewhat by the use of a louder muffler. There’s a science to it, but generally speaking you should try to match the factory pipe size whenever possible.

As far as single v. double, single is usually more efficient in terms of performance. One pipe is sufficient to flow the exhaust gases, and the factory system is configured for a single pipe. If you can stand the fact that your truck will sound better on one side than the other, a single exhaust is best. However, all that being said, it’s not a huge difference between single and double (in terms of performance). If you dyno-ed both configurations side by side I doubt you’d notice a significant difference – probably less than 2 hp.

So, in summary, out of your two options, I like them both. Simply replacing the factory muffler is least expensive, and you might find the sound to be pretty good. If you add two slightly smaller pipes in place of one larger one, you’re probably going to break even in terms of performance and you’ll have a good looking setup. If I were to make one suggestion, it would be to find another muffler shop and get a quote from them. You might like the options they give you better.

Check out this list of available Toyota Tundra shocks

However a lot of people like to go as “factory” as possible when choosing accessories, and we can certainly understand why. First of all, it’s very easy. If you’ve bought a Tundra, chances are you trust Toyota to make a good product. You can rest assured the TRD exhaust system is a good choice. Secondly a lot of people like factory-backed accessories because they know their won’t be any warranty concerns. Unlike adding an after-market kit, where the directions clearly state “this may violate your factory new vehicle warranty“, you know that a new kit from TRD isn’t going to cause any warranty problems. Finally, there’s just something to be said for having a very “stock” look and feel, even if you have added a bunch of extras.

Whatever your motivation, TRD’s kit is definitely a good choice. To start with, the kit is solid mandrel-bent 409 stainless. 409 stainless is about as good a material as you could ask for, and the mandrel-bent manufacturing process means that any bends in the tubing were done without compromising strength or shape. Since preserving the round shape of the pipe enhances flow, it’s always important to make sure a kit is mandrel bent. Finally, the TRD dual exhaust kit includes double-walled stainless steel tips with an engraved TRD logo. Nice. Looking at a brand new kit, it’s clear that TRD didn’t go cheap.

Installation is also about as easy as they come. This is literally a bolt-on kit. The hardest part of the installation is removing the factory system and dealing with those pesky hangers. If you wanted to, you could definitely put this kit on yourself with basic tools. If you wanted to have someone install it for you, it shouldn’t cost more than $100-$150. Most technicians can have this kit on in under two hours.

Like all after market accessories, there is a lot of argument about just how much power this exhaust kit adds. Generally speaking, after market exhausts by themselves offer little in the way of additional power. Typically, the most you’ll see is a 3-5 hp gain with just about any cat-back system. The TRD kit is no exception — our tests show that the TRD Dual Exhaust for the new Tundra added anywhere from 1 to 5 hp. Unfortunately, the increase in horsepower varied quite a bit depending upon RPM. That’s why we like that “3-5hp” number. Check out the dyno performance graph below.

Click for a larger view.

NOTE: Our dyno tests were conducted in 5th gear, and we truncated the RPM range to ensure that the comparison was as accurate as possible. Unfortunately, tests had to be conducted on different days due to time constraints at the dyno shop. We expect a margin of error of +/- 1 hp.

If the horsepower number doesn’t excite you, when you factor in the feeling you get when you step on the gas, you will feel like adding an exhaust is the best money you ever spent. The TRD kit is excellent in terms of sound — little or no additional noise at idle (almost imperceptible at true idle — very impressive), minimal highway “rumble”, and absolutely fantastic sounds at W.O.T. This kit was designed by Toyota to provide the sound that a lot of V8 owners crave while still being quiet enough to preserve the truck’s finer qualities. This perfect balance of sound is easily the TRD kit’s best attribute.

Here’s some video of the truck’s exhaust — make sure your speakers are on for this one:

Click here to view the embedded video.

Check out this Tundra Solutions thread for more TRD exhaust sound clips (props to mxsjw for posting those sound files).

Like we said in our Toyota Tundra exhaust guide, adding an exhaust system alone isn’t going to get you much power. But if you combine the exhaust system with any other upgrades (like a cold air intake), you’ll likely see a multiplying effect for both. As for adding this kit to your truck, we’ll tell you that the list price of the TRD exhaust kit is $1,154. Some other big names offer kits that are very comparable for less money. We’ll also say that your local muffler shop can probably build you a custom system from scratch for even less than any of the kits you’d buy online, and that your local shop will build a system with equal or better performance than any pre-fabricated kit. In other words, the TRD kit is a little too expensive for our tastes, especially when compared to the local muffler shop. However, if you’re only interested in pre-fabricated cat-back systems, the TRD is an excellent choice.

Don’t get us wrong — the TRD kit is quality, backed by Toyota, and as good as anything you’ll find. In fact, we’re willing to bet this kit’s sound aspects are probably the best on the market (but we can’t back that up until we do some more testing). “If you have the means, we highly recommend it.” [Incidentally, we were able to find some discounted pricing for the TRD exhaust. We're working on getting it for our readers, so stay tuned.]

Bottom Line: The Toyota Tundra TRD Dual Exhaust is excellent, but it’s a little overpriced. If you want to add a quality, factory-backed exhaust system that won’t make your truck sound like a dragster, the TRD product is an excellent choice.

Check out this list of available Toyota Tundra shocks

To start with, Toyota took the time to design a quality exhaust system. In other words, if you never modified your Tundra’s exhaust, you wouldn’t be disappointed. Toyota designed the whole system to be efficient, starting most importantly with the exhaust manifold. That’s because, basically, the new Tundra comes with factory headers (most trucks don’t).

The exhaust manifolds on this truck are some of the most sophisticated factory exhaust manifolds you’ll find — they are a 4 into 2 into 1 design, which has been found to be most efficient for moving exhaust gases quickly. The exhaust manifold is also made out of stainless steel, which is lighter than cast iron (the material most manufacturers use) and more resistant to corrosion. The tubes on the exhaust manifold for each cylinder are also of equal length. Often times, factory exhaust manifolds have unequal length tubes, resulting in different back pressures on each cylinder and contributing to lower performance. By making sure that that cylinders all have equal length tubes, the Tundra’s factory exhaust manifolds are as good as most products available after-market.

In short, the exhaust manifolds on your new Tundra shouldn’t require any modification. If you decide to heavily modify the top end of your motor, then you may want to look into a quality after-market header (when they become available), but for 99% of users, the factory setup is excellent.

From the exhaust manifold (one on each side of the block), your exhaust is going to pass thru two (2) catalytic converters. Unless you intend to race this thing off-road, there’s no good reason to remove your catalytic converters. First of all, it’s illegal to do so. Second, it’s bad for the environment. Third, and most significantly, they really don’t result in that much of a hp loss. Once upon a time catalytic converters would restrict your exhaust significantly. Today’s designs (in the Tundra and otherwise) are fairly performance friendly. Don’t get me wrong — you’d get slightly more performance without them, but do the world a favor and leave them on. Stick with a cat-back exhaust modification.

After the catalytic converters, the exhaust gases from each side of the motor cool somewhat and meet-up at the muffler. Again, the factory system is pretty good. We haven’t tested one, but typically we don’t see a significant hp and torque gain by replacing the factory muffler (3-5hp, 5-10ft-lbs at the most). We are very interested in any dyno testing that anyone has done to confirm or disprove this. However, if you supercharge or otherwise heavily modify the engine the factory muffler should be replaced.

If you decide to replace the factory muffler, the biggest benefit will be the new sound that you hear coming from the pipes. The rumble that we all associate with a V8 is intoxicating, and there are about a hundred different mufflers to choose from to help you get the rumble you want. TRD, Borla, Flowmaster, Gibson, Edelbrock, Magnaflow, etc all offer quality products. While brand is important, it’s more important to know what you want and find the right shop. Most exhaust mufflers, regardless of brand, are interchangeable. Whatever brand you choose, it’s important to remember a few things and ask some good questions at your muffler shop.

First, what do you want? Most people want to hear the exhaust rumble at idle and under acceleration, but not really while cruising on the highway. If you get the wrong muffler, you’ll end up hearing an annoying drone at highway speeds. The experts at the local muffler shop can help (read more about picking the right shop below). Second, do you want something that people can slightly hear when you drive by, or do you want something so loud that the neighbors know exactly what time you leave for work every morning? I hope that it’s the former, but if you decide for the latter, look for words like “racing” or “glasspack”.

Also, do you want a single or dual exhaust? In terms of performance, you usually see the best increase by copying the factory system but upgrading the components. On the Tundra, that would be a single exhaust. But since you’re not going to see much of a performance difference either way, dual exhausts do look and sound better, and that would be our preference.

What material is best? We think that’s a decision that should be based on geography. If you live anywhere near the corrosive effects of saltwater, stainless steel is the smart choice. While it’s more expensive up-front, it will last much longer than galvanized or aluminized steel. People living in dry climates really don’t need to purchase stainless steel — if rust attacks their system, it will be years before anything is damaged.

What about exhaust tips? First of all, go stainless. Anything else will be hard to keep polished. We’ve gone cheap on this in the past and regretted it. Ask to see the tips you’re going to buy along with a cheaper set. If they weigh the same, you’re probably looking at something with a coating. If the expensive set is lighter, you’ve got the real deal in your hands. Tip size shouldn’t be too big either. If you get huge, coffee-can-sized exhaust tips, your back pressure will drop a lot. That’s actually a bad thing — a little back pressure is needed to help the engine perform (it was figured into the design). We recommend sticking with something the same size as your stock exhaust or just a little bigger.

Last, when choosing a muffler shop, ask a lot of questions. We’ve installed a few exhausts and had some bad experiences, so these questions are based on you not making some of the same mistakes we’ve made.

1. Explain your plan to the shop owner, and then ask for their opinion. If they don’t give you a decent response, you’re not dealing with someone who understands what you’re trying to accomplish. Go somewhere else.
2. Ask for a brand recommendation. The best shops will tell you about their premium muffler (i.e. Gibson, Flowmaster, etc.) but they’ll also mention their shop brand. Ask them which they would choose. If they tell you there is much difference between the shop brand and the premium brand, make sure that’s not because they’re trying to sell you a more expensive option.
3. Find out what vehicles they specialize in and if they work with any local car clubs or racing associations. If the shop you’ve found works with a local SCCA chapter or off-road club, they’re probably excellent. If they specialize in import compacts, you may want to go somewhere else.
4. Ask for referrals and recommendations. Reputable shops will be able to list off five or ten local businesses (mod shops, car dealers, etc.) that they work with.
5. Ask them how they assemble the system, how the tubes will be bent, if they’re going to use the factory hangers, etc. If you don’t like the answers you get, you might want to shop a little more.
6. Don’t spend more than about $600 for a cat-back system (installed). We like the TRD product, but for $742.50 (a recent quote we got from a local dealer) PARTS ONLY, we think you could have a nice exhaust system and a half a dozen cases of beer.

Last, check out this recent install by blackgts2002 (must be forum member to see profile), a member of TundraSolutions.com since 2005. He had a dual Flowmaster 70 series put on his new 5.7L Toyota Tundra. We especially like it because of the quiet tone at idle and at steady RPM, while still sounding very impressive under acceleration. The duals look great (he’s chosen what appears to be a quality tip), and the cost and quality is exactly what we’d expect from a good shop. We hope you have the same success with your custom exhaust set-up.
Nice!

2007 Toyota Tundra exhaust system dimensions:

These were found on the TundraSolutions forum — make sure you check your own setup before ordering anything.

Exhaust pipe outside diameter measurements:

At rear of catalytic converters: 2 3/8 inch

From post catalytic flange to factory muffler: 2 1/8 inch

Out of muffler to exhaust tip: 2 3/4 inch

Check out this list of available Toyota Tundra shocks