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Discussion Starter · #1 · (Edited)
Which Exhaust do I get???
So, you just bought your first LX and possibly even the first car you have decided to modify, and in this case we will assume a 5.7L or SRT8 although this applies in part to the 3.5 V6 LX's. The first mods people typically do are Intake, Exhaust, and Wheels. For now let’s focus on the exhaust system, and more specifically the CAT-Back portion of it as the complete exhaust system starts at the header/exhaust manifold and ends at the exhaust tip(s).

Most car manufacturers leave room for improvement when it comes to horsepower and torque and this includes DCX. This is not to say that these vehicles are poorly made, but many companies use less expensive alternatives when producing items such as exhaust systems for their vehicles.

A performance exhaust can free some of the power in your engine. These aftermarket systems allow for a quicker, more efficient path for exhaust gases to escape. This means your engine "breathes" better, so spent fuel and air exit the combustion chambers faster and new fuel and air can be burned to create more power.

In many cases these aftermarket systems are lighter than the stock exhaust as well… Why is that important? Rule of thumb is for every 100lbs lighter your car is you are faster on a quarter-mile by 1/10 of a second.

There are several other advantages to adding an aftermarket exhaust system. One of the most noticeable advantages is a more aggressive exhaust note. Depending on the system, you'll get the more aggressive, deeper rumble that is found on most high-end sports cars. Many of the better systems are only slightly louder than your stock exhaust, and deepen to a low "growl" as your RPMs rise during acceleration.

The way the pipes are bent also affects the exhaust flow, and there are two types of bends used in making exhaust systems. The typical factory-made systems, as well as some aftermarket systems, use a "crush-bend" technique. This type of process creates a crinkled area in the pipes, decreasing the diameter and slowing exhaust gases. A mandrel bend is smooth, and does not affect gas flow. The pipe is a constant diameter through the bend, yielding less resistance for a more efficient and better performing exhaust.

Another factor to consider is the material used to make the system. Most factory exhaust systems are made of mild steel, meaning they have a tendency to deteriorate over time. Better aftermarket systems are constructed of aluminized steel or stainless steel. Aluminized steel offers slightly better longevity over stock systems, while stainless systems are designed to last much longer, usually for the life of the car.

When exploring further differences in exhaust systems, it becomes more important to factor in how you use your vehicle. Most aftermarket systems add to your car appearance, with larger tips and highly polished mufflers for a more refined, aggressive look. There are many aftermarket systems that allow you to retain a stock appearance, while still seeing performance gains. The diameter of the pipes used in the system is also dependent on how you use your car, as well as whether or not you are adding further aftermarket performance parts. Most cars benefit from slightly larger piping, but if you go too big, you can actually hurt your vehicle's performance. On the other hand, if you are adding forced induction to your vehicle, such as a turbocharger or supercharger, you will want to go much larger than your stock exhaust.

The most agonizing decision to make is WHICH system to buy. By now or very soon from now you will read or hear other LX’ers comments regarding exhaust drone. Some find this annoying and others simply pay no attention to it. Please see the quick note on exhaust drone at the bottom of this post.
As far as the anxiety ridden decisions you have to make are of the tone and noise level you want as well as the looks, overall performance, and of course price.

At the lower end of the spectrum in price is Magnaflow, SLP, and JBA to name a few. All of which are quality systems and are used by a large number of your LX brothers and sisters. At the mid-range pricing level are your Borla systems and such, and at high end are Zoomers, Corsa, Billy Boat, etc etc…

All of the system above have their pros and cons, and trying to decide which one to go for can give you a bad headache.

No matter what direction you choose, an aftermarket exhaust is sure to add to your car performance, appearance, and sound. Take into consideration what direction you want to go with your vehicle, whether it be performance, show, or simply an improvement over stock. The right exhaust system can dramatically change your car for the better.

Prior to buying your exhaust it is strongly recommended that you meet up with fellow LX’ers in your area. No doubt there will be a sampling of most systems available for your to hear and ask the drivers their opinions.

A Quick note on Exhaust Drone
What exactly is exhaust drone you ask? Well…Drone in the exhaust is due to the engine driving the exhaust system at its resonant frequency. You can't get rid of it, any length of pipe has a natural frequency, but you can change the frequency (RPM) it happens at. Stock exhaust systems are tuned to put the resonant frequencies outside the normal RPM range the engine is run in. Sometimes they add resonators for this purpose.

How exhaust drone can be changed… Unfortunately this really does not apply to our LX’s however. To raise the resonant frequency of a system, shorten its length. To do this, you can try tail pipes that exit by the wheel (like GM's have), or you can try a muffler with a shorter internal flow path. If you have a true dual system, you can change the natural frequency of the system dramatically by adding a balance tube. If you can't shorten the system, then you can add slightly less than one wavelength of pipe. This will also raise the resonant frequency of the system. The wavelength in a single converter system (not true dual) is a little less than three feet at 3000 RPM. Shortening the system by a foot or so will move a resonance at 2000 RPM to about 3000 RPM.

To move a resonance, calculate the wavelength at the RPM that gives the resonance you want to move. Then calculate the wavelength at the RPM you would rather it be at. The difference is the length of pipe you need to add or delete. Add to lower the RPM, delete to raise it. If you want to raise it but you can't cut any pipe out, then add one wavelength of pipe minus the amount you calculated. This will have the same affect. If you add or subtract a multiple of a wavelength exactly, you will not change the resonant RPM.
 

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I agree, nice write up, thanks!
Now we need someone knowlegable in the systems to write up a review of the pro's and con's of say Zoomers vs. Billy Boat vs. Maganaflow vs. etc etc.
-J
 

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Discussion Starter · #4 ·
I could do that but being a vendor some would read that as bias.

Personally I think the Corsa is the best on the block if price is no issue. After that with price NOT being an issue Billy Boat, then Borla 125 with the 5" tips but it is aggressive, and of course JBA the best bang for the buck in my opinion for those that want the performance and sound but not break the bank.

I run the Borla 125 with the 5" tips on my Magnum...

E
 

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5" sounds huge, what are the stock SRT's 3.5"? What size pipes are you running? I like the sound of the Zoomers in the Superbee video that's going around right now but that may be a bit too loud for me. What might give a similar sound only a little less loud without drone in the 2K-4K RPM range?
My Ram has Flowmaster 40's on it and while I love the sound it's just way too loud for the Bee.
 

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I have never installed or driven an LX with Bassani... My understanding is they are good systems... Sorry for the lack of info on those.

E
What's your opinion on SLP? I know it sounds great. How is it performance wise? Seems like it would flow well.
 
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