dudemandanman

as the title says, how can i bend exhaust pipes. i want to do a custom true dual set up and want to do as much as i can myself to save some money, so i want to know if i can bend the pipes myself without one of those pipe bending machines.

i'm not looking for drasting 90* bends, just a little tweaking. i was gonna go about just heating up the pipe with a torch at the bend and hope it gets soft enough to bend it.

will this work?!?!

please leave some feedback.

thanks!

Redneck Z

iTrader: (3)

If you heat up your exhaust and bend it, you'll neck down the inner diameter of the pipe. It will probably flow worse than your stock exhaust! If you have a muffler shop press bend it for you, it MAY be a little better than your stock exhaust. Just save up untill you can do it right, unless you don't care about power and are just looking for a noise maker.

emerica4601

iTrader: (5)

i already tried this approach with my previous car. dont go the cheap way. save up and have it done professionally at a muffler shop where they can do mandarel bends. yeah, heating the pipe will work if u want to bend it, but ur talking time, precision, and many frustrating headaches.

300bhp/ton

The only way to bend pipes is with a pipe bender, you can hire these. But to be honest if you didn't know this already I think you may be biting off more than you can chew.

magius231

iTrader: (8)

you can also buy mandrel U and J bends from Jegs, Summit, or maybe your local exhaust shop, and cut and paste them together.

If you don't know how to weld good forget it, let a shop do it or buy a kit. Don't try to bend your pipes with a torch, all your going to do is pinch them, sort of like bending a drinking straw too far.

GuitsBoy

iTrader: (4)

This was the approach I took. However if anyone ever looks under my car, they'll have a good laugh at my welding.

dudemandanman

wow, its a good thing i asked haha.

well looks like i'll just have an exhaust shop do it right for me.

thanks for all the input!!!

magius231

iTrader: (8)

I almost did it too, but I realized exactly how limited my welding skills are at this point, how limited my time was, and decided it wasn't worth having my car down for a week

indyboom

iTrader: (11)

Here what you need... Two fat dudes.. And one tree... Its as simple as that

jdaniels

iTrader: (12)

Having an exhaust shop do it, and having a PERFORMANCE exhaust shop do it are 2 different things. 99% of exhaust shops will only have a crush bender, not a mandrel bender.

Make sure you know what you're paying for.

300bhp/ton

A normal pipe bender is fine in most cases. Unless you are planning (seriously planning) well over 450rwhp I doubt a crushed bent pipe will really have much affect on HP.

GuitsBoy

iTrader: (4)

I agree here. Crush bent duals still have more cross sectional area than a single 3" pipe, which has been proven well north of 450 HP. IMO, the crush bends will affect the sound more than the power output, and eve that will be a slight change.

Redneck Z

iTrader: (3)

Not only do crush bends suck, but they also create turbulence which causes energy/power loss. Crush bends are junk IMHO, and I've seen dyno's proving this.

GuitsBoy

iTrader: (4)

Funny, cause ive seen dyno results disprove this. Ive also seen dyno gains of 16 RWHP from absolutely nothing on my very own car. A few HP here or there is well within the margin of error for a dyno and does not constitute a valid gain or loss, IMO.

Silver02Z28

iTrader: (2)

+1
Don't try to bend them without a high dollar bender. Cheap benders just crimp or pinch. Mandrel benders cost thousands.

Redneck Z

iTrader: (3)

Like anything else on here, there are dyno's showing all kinds of things. You'll also probably find dyno's showing 15rwhp from a K&N filter also. You kind of have to weigh things out to come to a conclusion. Most of the dyno's I've seen on crush bent TD's have not been very positive. Just by looking at a crush bent setup, it's easy to see why it's not optimal. There's a reason people pay alot more for mandrel bends.

GuitsBoy

iTrader: (4)

Most of the crush bent setups that ive seen lose power were 2 1/4 piping. But it depends on how well it was fabricated. Ill bet that in the wrong hands, mandrel bends could be put togathe poorly enough to show a loss. Im not arguing that crush bends are as good as mandrel bends, certainly not. I just dont think the gap is as wide as people here will tell you. Personally, I have all mandrel bends over the axle all the way to the tips, and Im glad I spent the extra money.

300bhp/ton

I personally don't think you should read too much into alot of these dyno results. I mean hell they can used to show just about anything.

Also crushed bends really aren't that bad, not if you're no where near the limits of the exhaust flow anyhow. On a 2.5" dual setup you'd really need to be looking at ~500rwhp Mustang Dyno.

And as for turbulance, well what happens when the exhaust gases pass thru a muffler? High performance mufflers can flow well enough not to affect flow of high powered engines, so I'm sure a crushed bend in a pipe can also.

And not all crushed bends affect the diameter that much, my brother had a crushed bent custom exhuast on his V8 Land Rover, the crush was actually very smooth and even with hardly any pipe diameter loss, maybe 1/16 to 1/8th of an inch at most but possibly not even that.

jdaniels

iTrader: (12)

Believe what you want, but crush bends suck when compared to mandrel bends. If you're looking for maximum performance don't settle for crush bends.

There is a reason why all performance exhausts made by reputable companies are mandrel bent.

Redneck Z

iTrader: (3)

I am probably a little **** when it comes to my exhaust because I look at arteries for a living. I see the kinds of hemodynamic changes that are caused by tortuous vessels and obstructions. I see older patients with tortuous arteries, that look just like a crush bent exhaust lol. This does effect flow in an artery, and I do see turbulence caused by the tortuosity, as well as a pressure drop beyond. Some of this can be applied to a cars exhaust, and I think thats why I pay extra attention in trying to maintain good curves when it comes to my exhuast.