Cat-back

[sccrAdidas15]

I have been recentally looking at cat-backs and havent been wanting to spend over 200 dollars on an exhaust system. I know you can get local exhausts shops to make you one but how much do they cost. and what is the difference between mendral bent and press bent?? Also can they just make you piping and you just put a muffler on it??? Feedback would be great thanks!!!

 

[illeagle_talon]

To tell you the truth, if you're not wanting to spend over 200 bucks on a catback then I recommend not getting one at all till you're ready to fork over a little bit more. Most muffler shops (not all but most) will only give you cheap restrictive press bent piping with a walmart muffler. Trust me I've been down that route and I regret it as I'm sure you will you too. Just save up and it'll be worth it. You get what you pay for. In the meantime if you really want to buy an exhaust piece, just buy a downpipe. You can find Apexi downpipes at most DSM vendors for under 200 bucks.

 

[Catbox_95]

I'm sure all exhaust shops are different, but here in the Houston area, they generally charge $25 per weld, and that will include pipe unless it's a huge length (and yours won't be). You can buy an APC stainless steel straight-thru muffler from O'Reilly for $109, bring it to a muffler shop and have them hack off the pipe after the cat, make a couple of welds with some new pipe and you're done. Worst case they should only charge like $75, so with tax and all you're outta there for $200.

Since you are leaving the stock cat, 2-1/2" pipe would be just as good as 3", and you won't need the expensive mandrel-bending. With mandrel bending, they stick the pipe in an expensive machine (that you pay for) and stretch the pipe as they bend it, so it doesn't decrease the pipe diameter at the bend, like it does with press-bending.

Hope that helps...

 

[Sourpatch]

listen if this is a half ass project and you really dont care then go get some shitty press bent pipe. If not you get what you pay for !

 

[Catbox_95]

Whatever.
Do you really think that a car making even 300-400 horsepower is going to see a difference in mandrel-bent and press-bent pipe?

No. You guys that spend over $700 on an exhaust are suckers, unless of course you're making like 600 hp.

 

[WSU99GSX]

Whatever.
Do you really think that a car making even 300-400 horsepower is going to see a difference in mandrel-bent and press-bent pipe?

No. You guys that spend over $700 on an exhaust are suckers, unless of course you're making like 600 hp.

It's not so much horsepower as it is efficiency, the less resistance, the more efficiently the motor can get those gases out, with smoother bends (mandrel) the air is able to move with less resistence. And please don't judge people who spend money on exhaust, they are not suckers.

 

[Catbox_95]

Sorry 'bout that. I didn't mean to judge.

I just really can't see how a 3" exhaust with press-bent piping would hinder horsepower from a 4-cylinder. 2" piping with press-bent, I could see that. But with 3"??? Seems like even after pressing it there's still plenty of flow.

 

[guitarXgeek]

You want to get those exhaust gases out as quickly as possible, especially on a turbo car. Press bends are known to KILL exhaust gas velocity, thereby restricting flow. A local guy did a test (mind you, this was on a turbo civic), he went from 3" press bent to 3" mandrel bent, and picked up 6whp on the dyno. Not only that, the car seems to breathe much better, and his spool-up time dropped ~100 rpm. Don't skimp on exhaust with going press bent, just shell out the extra dough and buy some mandrel pent pipes, take them to an exhaust shop and have them weld it up for you. Road Race Engineering has a 2.5-3" mandrel bent dp for like $200. They also sell 3" mandrel piping for pretty damn cheap. This is the route I went, and the total cost was ~$500 INCLUDING an evo3 o2

 

[Catbox_95]

I guess there may be some argument there as to getting more performance from mandrel bent pipes, but the results are small. It's all relative. I bought my muffler from O'Relly for $109 and the local shop built a custom (but press-bent) full 3" exhaust from the turbo to the muffler for just $135. So, that's $244 for the complete system. I'm not sure I would spend another $256 for just 6 hp. But then, some people would.

As for performance increase, I simply could not believe the difference that exhaust made on my car. There's just no other way to put it. From a crappy stock 2" with lots of tight bends, 2 resonators, crappy muffler and a clogged cat - to full 3", no resonators, no cat, less bends and straight-thru muffler - yeah, it's MUCH better! My engine is breathing so much better I am now experiencing fuel cutout, so I just ordered the Walbro 255 lph and SAFC. Babysteps!