white1

iTrader: (5)

How important is mandrel bent exhaust pipe? I can't find anyone around who can mandrel bend pipe, but they are willing to order mandrel bends, and weld them together.
Anyway, really how much do you gain going to mandrel bent pipe. Mine isnt mandrel bent, but its not choked down much anywhere eigther. Just wondering how much Im leaving on the table. 1-2 hp, or 10-20??

white1

iTrader: (5)

Oh btw, this is a N/A application. currently I have factory manifolds, straight pipe to the Y. Factory Y pipe, into a single 3" cut out to 3" Bullet to 3" Magnaflow tunning out the back and dumping behind the rear tire.

BlownChevy

iTrader: (20)

Mandrel bends are nice.....is there alot to gained from them, well that all depends on the HP you are making. I personally dont think anything under 1500 HP would benefit from a mandrel bent exhause....but that is my opinion not fact.

white1

iTrader: (5)

Thats kind of what I was thinking. I know it makes a bigger difference on F/I applications, I just dont see where there is a huge restriction, so I figured it really didnt matter for me.

crazyidiot4.8

matt,
darryl @ autotech in gonzales does mandrel bending i'm pretty sure. and he does good work for cheap too. i don't let anyone else touch my exaust anymore but him

hog

mandrel bends are cool and everything, but by just running the next size larger pipe accomplishes a lot more flow wise. A 2.5' mandrel bent piece will not outflow a 2 3/4' crimp bent piece.

of course this all depends onthe quality of the normal bend, if it crimps horrible them of course the mandreel bends ar going to flow better.

headers are mandrel bent.

Hog

white1

iTrader: (5)

Thats who did mine. Its not mandrel, we talked about it, and both agreed, I was just wondering what some other opinions were. I definatly did find a new muffler guy though.

CrabhartLS1

Really it doesn't matter that much. if you're running FI and you have crimp bended headers (i realize they don't make such a thing) then you would see an inprovement with mandrel, or if you have a very restrictive exhaust system otherwise, you might see improvement.

But on the whole, if you have 2.5" true duals going, or a 3" Y pipe to a single pipe of the same diameter, there's very little to be gained by going to mandrel bends.

BigKID

iTrader: (5)

It really depends on the size of the pipe, your flow requirements and the angle of the bend in question. Anything under 45* I would say crush/crimp bends will be fine as long as the pipe diameter is 2.5" for dual or 3" for single. If you have a 90* bend in your system, especially if it is a 2.5" or smaller, the flow is going to be severly hampered by a crush where a crimp wouldn't be as bad. The thing about a mandral bend is that no matter what the degree of the bend is, the pipe diameter stays uniform. On a crimp bend, the higher the degree of the bend, the more the pipe is ovaled or flattened. With a crimp bend the diameter is reduced as well as creating an unsmooth surface on the inner wall of the bend creating more turbulance in that area. If you exhaust guy is good, he should be able to fabricate you a good flowing exhaust with a series of shallow crush bends instead of a few deep (>45*) bends. If you look at my exhaust, I only have one 90* bend (over the axle). The rest are 45's eventhough they are mandral. If they weren't, I would have had it fabricated with a series of more shallow bends.

moregrip

iTrader: (8)

That sounds about right to me as well. I'd only like to add that mandrel bent pipes can impeed flow as well. As the tooling ages the consistancy of the bends will suffer if not properly maintained/replaced.