Muffler Tech

Question: Does a dual cat-back exhaust system perform better than a single?

Answer: In most cases a single exhaust will give you better torque and horsepower. For example: Fairlady Z, while the stock is dual outlet, a single pipe layout show more horsepower gain. The exception would be a heavily modified engine/race car. 


Question: How much horsepower can I expect to gain?

Answer: It's different for every car, but typically expected gains are in the average range of 10%.

 Replacing the muffler/exhaust with 5ZIGEN will help your engine increase power by being able to expel exhaust gases quicker. This creates less workload for the engine, makes it run more efficient, and results in better power. Please understand that newer vehicles have advanced computer systems, so the gains will not show up that easily compared to older cars.
Remember, street legal systems are design for optimal gain within legal standards. Do not expect to gain much power as compared to competition type mufflers.
Also, peak power in some vehicles is not the only answer. Most of the time especially for street use, mid-torque range gains are substantially more important than the peak power gains. This is because you would not drive your car at a maximum speed enough to feel the difference. Why? Driving over 100mph is illegal. A raise in mid-torque ranges means better response when getting on the onramp of the freeway or if there is a need to hit the gas to avoid an accident, etc.
When checking the dyno for numbers, try checking the torque gains as well.

Question: Why are some systems loud and some quiet?

Answer: Street legal systems often have a set decibal reading at certain rpm range. This means that during the R&D process, we have to take into effect the loudness of each exhaust and the power gains that come with it. Often meaning a quiet exhaust. Competition mufflers often called race mufflers are a different story. R&D is put into the muffler for optimal power/torque gains without the worry of decibal ratings. This is why when you go to see a race, all cars are loud. This is not just because of the muffler change but because the overall vehicle is modified as well. So, before someone says this exhaust is loud, check to see if the system was made for the street or track. Manufacturers besides us such as Greddy, HKS, Fujitsubo also have street legal and race muffler applications.

Question: Why ISN'T a bigger pipe always better?

Answer: Don't be fooled! Bigger is not better! Many people think that having the biggest diameter pipe is the best way to make power.
Not true. Due to a variety of factors, extensive testing is required. We've dyno'd extensively and our systems yield optimum power increases. Some manufacturers claim even higher horsepower numbers. 

It is a fine line to reduce backpressure while maintaining good exhaust velocity. It is not about getting the biggest pipe, it is about getting a more efficient pipe diameter while maintaining exhaust velocity. 

There has to be a balanced design to enhance the maximum engine output, exhaust gas velocity, and sound. This is why it is important to get the correct size piping in order to relieve backpressure while maintaining thermal efficiency. You will be surprised that some cars gain power with a smaller diameter.

Question: Why 5ZIGEN?

Answer: No one in the aftermarket industry has a history like us. We have been professionally racing for over 20 years. All maintenance are done in-house. Race categories include Karting, One-make, Super Taikyu, Super GT(formula JGTC), F4, F3, F1600, Rally, and the highest ranked race in Japan: Formula Nippon(next rank to Formula 1). We extensively take data from these race experiences and apply it to our products. We are members of JAF, JASMA, and have ISO 9001:2000 at our Osaka Yao Factory.

Common Advice:
If you are purchasing an exhaust system/headers
1.) Know where your items are manufactured
2.) Take the time to know which materials are used. There are countless types of material being used. For example, for stainless alone, there are nearly 10 types. Purchasing a cheaper system often means cheaper material used & proper R&D was not carried out. All our items display which material is used for which portion.
3.) Know the difference between street legal systems and competition type systems. There is a reason why some systems are quiet and some are loud.
4.) Raw material costs have been rising! If you find an all stainless system that is extremely cheap, there is a reason for it!!!
5.) Do your research-it's worth it!

If you have further technical questions, please feel free to drop us an e-mail: mail@5zigenusa.com