Hey guys,
a couple quick exhaust questions for ya. A buddy and i are planning to build a custom cat-back system for my car. The plans are to start at the last cat and replace from the intermediate pipe back. What we have planned is going from there back to a custom "Y" pipe and splitting it to exit out the back as duals. We are gonna use all stainless piping. My main question: Is 3" pipe going to be too big? I was boucing back and forth between 2.5" and 3", but i really like the idea of big pipes!! Also forgot we are gonna end with some kind of stainless tips too. Any advice will be appreciated. Thanks in advance.
L.J.
Go with 3". As for the duals, I have them on my car, they were a pain in the ass to do and I doesn't look that great in my opinion. I will be getting a new exhaust soon and am planing on selling my current cat-back that is 2.5".
If you decide to go with duals, don't put a muffler on or if you do, use 2, I can take pictures of my setup if you want something to work off of.
Originally posted by newbe02WRX Hey guys,
a couple quick exhaust questions for ya. A buddy and i are planning to build a custom cat-back system for my car. The plans are to start at the last cat and replace from the intermediate pipe back. What we have planned is going from there back to a custom "Y" pipe and splitting it to exit out the back as duals. We are gonna use all stainless piping. My main question: Is 3" pipe going to be too big? I was boucing back and forth between 2.5" and 3", but i really like the idea of big pipes!! Also forgot we are gonna end with some kind of stainless tips too. Any advice will be appreciated. Thanks in advance.
L.J.
Well for one, in my opinion Duals on a WRX is super GHEY, not to mention the added weight for no performance gain whatsoever. If I were vulnerable enough to do dual exhausts on a WRX it'd be a Stainless Steel Downpipe and then aluminum piping all the way back to the lightest cans possible.
Do you know the definition of rice? Rice- Something on one's vehicle for no purpose whatsoever other than to look "cool".
forgot to mention that we are gonna straight pipe it. No mufflers at all. Pics would be great if you are willing. Better yet it looks like we aren't far apart i would be willing to meet ya somewhere and look at it in person it that would be easier. Also did you use the stock rear bumper? Thanks again.
L.J.
Blue,
thats cool everybody is entitled to their opinion. I am just looking to do something that is different and that i haven't seen on a WRX. I am not really concerned with the added weight as i don't really race the car. Who knows what my future holds for mods, but i plan on adding some power and this is where i want to start so thats what i am gonna do. RICE or not i think its gonna be cool.
L.J.
Originally posted by newbe02WRX forgot to mention that we are gonna straight pipe it. No mufflers at all. Pics would be great if you are willing. Better yet it looks like we aren't far apart i would be willing to meet ya somewhere and look at it in person it that would be easier. Also did you use the stock rear bumper? Thanks again.
L.J.
We are pretty close in deed, bout 30mi or so. I did use the rear bumper.
As for rice, maybe. But BlueDemon, I take it there is nothing on your car that serves no purpose? Gold rims, decorative, seats, decorative IMO.
Originally posted by WRXtreme As for rice, maybe. But BlueDemon, I take it there is nothing on your car that serves no purpose? Gold rims, decorative, seats, decorative IMO.
Gotta agree on that one Blue. No reason to flame the guy for being different. YA BIG JERK!
We are pretty close in deed, bout 30mi or so. I did use the rear bumper.
As for rice, maybe. But BlueDemon, I take it there is nothing on your car that serves no purpose? Gold rims, decorative, seats, decorative IMO.
Well, I actually can counter both of those: Gold Rims- the symbol of Subaru WRB cars. Seats- more for comfort and the leather, with the added benefit of being decorative.
There honestly isn't very much, if anything, that could be considered rice on my car. But to be fair, each person has their own interpretation of the definition of Rice.
However, when someone states they don't care about going fast, but wants to add power to their car by ADDING unnecessary weight, is just beyond me. Listen..... newbe02WRX, there is something called Thrust to Weight Ratio Which basically states that the more weight you have, the less thrust you have. Not to mention you said "Cat Back" now if that was a misnomer, than fine so-be-it, however, adding 50 pounds of steel (Or whatever the weight may be) without taking out cats, or taking any weight off elsewhere is going to get you nothing but LESS power, and LESS speed. Furthermore, keeping the stock rear bumper, which has a slight cutout for the stock exhaust, will NOT look good.
It's fine to be one of the first to do something, but try to make it look good AND be functional at the same time.
As for newbe02WRX, I've been doing the same thing but with the dual tip look. So far, (im taking summer classes so I have no time) I've been able to figure out the pipe diameter and the set-up, but have yet to take the measurements to be able to schetch the dimensions of the piping (like the curvature and stuff).
I'll give you a lead since it seems you have the time to do this project. In order not to loose power:
{Sum} dm/dt (Enter) = {Sum} dm/dt (Exit)
Where m= mass of the exhaust gases. So, in order to do that:
{Sum} dV/dt (Enter) = {Sum} dV/dt (Exit)
Where V= volume of the exhaust gases.
And if you remember from High School Physics:
dx/dt= velocity
Finally, the only easy way to do this is to alter pipe radii. So I would suggest to decrease the pipe diameter to 1.5 at the two exits after the "Y" section.
PS
Sorry for the Thermodynamics class. Just had to show you guys that I was not inventing this stuff, and that I am infact working on this, slowly, but working. Good luck man....
O yea... THIS IMAGE IS PHOTOSHOPED, so dont give me hell like last time :
O yea, as for what Blue said bout the Thrust to Weight ratio, (personally I've never heard of that) I can say that when it comes to power cycles (such as a motor), there must be a large increase in weight in order for that law (????) to make stand. The thing is that a car has four wheels. All the wheels touch the street, thus creating friction and a loss of energy which the motor has to produce (and a bit more) in order for the car to move. Now, because it has four wheels, the increase in the frictional force (due to the increase in weight) is completely negligible. So, the double exhaust set-up will not cause NOTICIBLE POWERLOSS AT ALL due to the weight, unless of course you use steel piping, but aluminum like someone said (Blue?) is fine.
Originally posted by T WREX *cough* painted side skirts *cough** cough* clear blinkers *cough*
Ok, if something that comes stock on a Japanese version is considered rice, then we're all in trouble. Not to mention, I stated that MY definition of rice was, to serve no other purpose than to look "kool". Painted side skirts and clear markers AND *cough* ### Spec head lights, are not there to look "kool". The serve a purpose in making the car look uniform, the way it was meant to look. Anyway, I get your point, you have a different understanding of the meaning of rice.
I only hope he understands that extra weight put on a car will do nothing but slow him down and reduce his overall speed.
Blue
Last edited by BlueDemon : 07-08-2004 at 06:12 AM.
Blue,
you do bring up a good point about the rear bumper. I don't really have the cash for a new rear bumper right now and i do agree with it not looking good with only one cutout. So maybe i'll reconsider and just do a single 3" cat back. Alluminized pipe with a stainless tip or something. Trying for a cheap CAT back setup. Anybody make a good decent priced cat back system in 3"?? Until next time.
L.J.
3 inch cat-back. Too Big??
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