Celica Forums General Discussion Exterior exauhst question

so heres a question that i hope someone can answer. i have heard that adding dual exauhst to a celica drops backpressure and although improving appearance(subject to opinion) lowers hp instead of giving gains.This makes sense and i agree with this idea. But i have also heard that just taking your muffler off gives the same gains as having a Performance muffler. To me taking the muffler off would cause there to be even less backpressure than if you had two mufflers working. So assumning that taking your exauhst off gives gains, why would putting duals on lower hp. Maybe i just dont know how a muffler works and i am being ignorant, but thats why i am asking the question. what do you guys think

thats what i thought most people would think...for example kazuma...thats just a straight though pipe pretty much. no back pressure there. i think there has to be an ideal amount of pressure in the exauhst system and thats what gives the gains. but im still waiting for someone to give a long explanation as to how the exauhst system is optimized

Wait for the Forum Troll Veterans to wake up

I've also heard that duals reduce back pressure and hp.
I've never heard that removing your exhaust will give you any Performance. I'm pretty sure that it will reduce your back pressure also.

Putting dual exhaust on a car that has 4 Cyl's isnt going to do anything besides sound and maybe a little gain. Because its not real "dual" exhaust. Dual exhaust is when there are 2 headers, and 2 different pipes completely seperate from each other ie. v6, v8. I would recommend just getting a normal cat-back exhaust.

i know, i am going to do it just for looks, its not going to do anything for sure i know. thats why i am going to just use on muffler and run two pipes out of it and run then back into my cutouts. i know this way its pretty much the same thing as having one muffler and leaving everything normal. but some people actually have two mufflers, maybe its a cali thing, ive seen two celicas w/ duals and i know its not true duals but it still looks nice. and as for people with no muffler and reported gains there is lucky for one. and im sure hes not the only one.and one person w/ duals would be morris.

Well if you like the dual exhaust look, go for it

but the question still stands..well i might as well add to this question. do you guys think that having headers affects the Performance of your muffler? of so what kind of combos have been known to work best for the celica?

http://www.magnaflow.com/07techtips/faq/question10.htm

^^^^this probably helps a little.. i mean its got some info

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. For example, imagine blowing air through a straw (comparing it to a smaller diameter pipe). This would take time to release all the air from your mouth, and you would feel pressure in your mouth while doing so. Now imagine blowing air through a paper towel roll (comparing it to a larger diameter pipe). You will relieve all your air much faster and feel little or no air pressure in your mouth because of the larger capacity of the tube. This is why it is important to get the correct size piping in order to relieve backpressure while maintaining thermal efficiency.

Use the guide below when calculating pipe size for custom exhaust work. Keep in mind that the goal is to improve exhaust flow. In most cases, just changing the restrictive OEM muffler and replacing it with the same size straight-through, Wide Open Performance MagnaFlow muffler will do the job.

To reduce additional backpressure, the OEM exhaust tubing can be replaced with mandrel-bent tubing of the same size or one size up from the OEM. As a general rule, you can enlarge the pipe diameter of your OEM exhaust system by 1/4 to 1/2-inch to increase your horsepower. However, any additional increase in pipe diameter is likely to decrease your Performance; specifically, low end torque.

simply put:

- too big of a piping or too much flow will slow your car cause of exhaust velocity

- too small and the engine cant breath out the excess and you slow down too

- good exhausts find that good midpoint where you can get the most peak hp gains

by the way theres a difference in the design and flow of straight through and dual mufflers like you want, its not like you can say cause Kazuma has 3" piping you can get two 1.5" pipings to match it. you can add such things, its like HP gains from mods, you cant add 5hp gain from an Intake with 8hp gain from an exhaust 5+8 does not equal 13hp when it comes to some of these things