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Old 29-11-2004, 10:38 AM   #1
applio
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less or increase power?

i am new to this forums. great forums....
anyways. i own a mazda 94 astina hardtop v6 2.0 automatic. i am going to put an air-filter and muffler on it. will this give the car less power or more power.
i been told that do the complete exhaust system will increase about 10%-15% power. so by putting the muffler is there any power increase?

Thankz
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Old 29-11-2004, 12:45 PM   #2
lamby1986
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limited to no increase in power would result, although it should make the car sound nicer.
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Old 29-11-2004, 01:11 PM   #3
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welcome ! glad to have you.

i dont expect just a muffler would add much performance. u might get slightly better response but otherwise the muffler would mainly affect the sound.

a full exhaust replacement is often not worth the $$ on a n/a car because they like a bit of back-pressure anyway. if you want to upgrade the exhaust maybe just a muffler and some extractors.

in my v6 I concentrated mainly on getting air and fuel burning and didnt worry about the exhaust. I had a k&n panel with the atock air ducts removed and new air ducts feeding up from the front of the car.

That and a rising rate fuel pressure regulator made a very noticeable increase in power and response.
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Old 29-11-2004, 03:47 PM   #4
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so that will be no power increae and no power lessed by adding air-filter and muffler, the effect just make the sounds better right?
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Old 29-11-2004, 04:38 PM   #5
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Apparently have a smaller exhaust benefits more power or torque or speed down low, a larger flowing exhaust benefits top end power/torque/speed. I read some article somewhere, i'll try and find it for you.
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Old 29-11-2004, 08:48 PM   #6
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Quote:
Originally Posted by Mizda_Mazda
Apparently have a smaller exhaust benefits more power or torque or speed down low, a larger flowing exhaust benefits top end power/torque/speed. I read some article somewhere, i'll try and find it for you.
thx
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Old 29-11-2004, 09:52 PM   #7
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Got this from r31skylineclub.com (i own a r31 as well, and if anybody knows anyone selling a rb30et please let me know)

"When deciding on what type of exhaust to buy, the first thing to consider is the aspiration type of your car. If your car is turbocharged, you will reap more benefits as you go for a bigger exhaust. However, if your car is naturally aspirated it requires backpressure, ie. the amount of pressure the exhaust gases place on the car's exhaust system. Fitting a more free flowing exhaust to a naturally aspirated car changes the cars torque curve. As backpressure is decreased, so is low end torque, yet top end power is increased. The reason such a restrictive exhaust is fitted to a car from the factory is that the car must cater for every type of driver, including the type that drive uphill in 5th gear at 40kmh (thanks to whoever it was i stole that quote from), ie. the cars tourque curve must have a lot of low end torque. Hence, when choosing your exhaust on a naturally aspirated car, you must decide how you want your car to act, and where you want your maximum torque to be.

If your car is turbocharged, this concept differs somewhat. Turbocharged cars benefit from free flowing exhaust systems, as the turbocharger is spun by the exhaust system. If the exhaust is more free flowing, the gases pass over the turbine faster, hence spinning the turbo faster, decreasing turbo lag.

The next question you must ask yourself is how big your exhaust system should be. Realistically, there are two choices in size when talking about a naturally aspirated R31; 2.25 inch or 2.5 inch. Whilst the performance difference between the two is negligible, other factors come into consideration, especially noise. The 2.5 inch system will be noticibly louder than the 2.25, and will also be more 'Droney'. Exhaust drone occurs when the exhaust piping resonates, creating a loud, constant, irritating humming noise. On a manual R31, a 2.5 inch system is acceptable, as the operating level of revs is not at the level the exhaust will resonate at. However, a 2.5 inch system on an automatic R31 will drone alot as the operating level of revs is at the correct frequency for the exhaust to resonate. A 2.25 inch system on an automatic will not drone as much, as the piping will resonate at a different level of revs.

On a turbocharged car, the larger the exhaust the more performance you will gain, and hence, 3 inch is a popular choice, as it is large enough to increase the turbocharger's speed significantly, yet doesnt create too much noise.

The next question to ask yourself is what type of exhaust system to buy. There are two types of beding systems used in the exhaust manufacturing industry. Press bending is done by putting the piping in a curved machine, and bending it around corners with that. However, this form of bending pushes the diameter of the exhaust inward, creating a restriction in the system. The other option is mandrel bending. A 'mandrel' is a circle of exhaust piping which is pressed without creating a restriction. The downside with mandrel bent exhausts is that they have to be cut and welded with pieces of mandrels and pieces of straight pipe, which takes more time, and hence, costs more to buy. Also, as the sections have to be welded, the inside of the pipng may not end up smooth.

The type of piping also comes into play when choosing your exhaust. There are two types of piping commonly available, Mild Steel and Stainless Steel. Whilst there is no performance difference between the two, stainless looks alot better (handy if you have a show car) and also lasts a lot longer.

Finally, you have to choose what sort of muffler to use, and how many to use. There are two common types of muffler, standard baffled and straight through. A standard type muffler sends the exhaust through an S shape, creating a lot of restriction, and dampening a lot of noise. A straight through muffler is just that, the exhaust goes straight through it and the baffles around it dampen the noise, although to a lesser extent than a standard type muffler."

Author lysdexia
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Old 01-12-2004, 10:52 AM   #8
skippy
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Far as I know no extractors exist for the V6,
if I am wrong PM me as I was looking for a while and would love to hear about some.


Are we saying there is no point doing an cat back exhaust if you can't get extractors?
or
no point in only changing the muffler if you don't do it from the Cat Back?
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Old 01-12-2004, 10:24 PM   #9
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if the effect of changing the muffler for the v6 will not decrease the power, jux make the sound better, thats sounds alright.....
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