Flex Pipe?

[taz2008]

hi, whats a front pipe with flex pipe? whats the benefits than a normal front pipe? thanks

[TTT]

flex pipe is usually used in FWD cars or cars with engine in east west config.

it essentially allows for the slight movement of the engine when you accelerate and back off etc.

looks like this.

On a front pipe, this would be at the point where the pipe bends towards under the car.

so off the turbo, bend down towards the ground, then at the bend back up to run under the car is where it goes.

it's to prevent exhaust from cracking at welds etc.

if you look at your engine when you rev it, it will lean to one side and back when you get off the pedal.

because most east west config engines have the exhaust at the front (some never ones have them at the back of the engine like the new Mazda 3 MPS), when you rev, the motors leans back and forth instead of left to right like a north south engine (eg RB and SR series of engines or any rwd car).

the back and forward movement of the engine pulls and pushes the exhaust.

the side to side movement doesn't cause this issue as

Edited February 22, 2008 by GTST

[taz2008]

so what you are saying is basically RB's dont need it?

[-_-StRyDeR-_-]

well depends on how hard your exhaust is mounted to your car? do you need a little flex in the exhaust so it doesnt stress the welds and joins??

[Duncan]

single turbo probably isn't important, but twin turbo / gtr setup you should never use a front pipe without flex on one of them. lets the turbos move a little independantly without cracking the warping/manifolds or exhaust

[R31Nismoid]

I would always use a flex pipe, single or twin.

[Busky2k]

If you have a stainless manifold, having a flex pipe helps reduce stress on the manifold when the motor moves around. Especially when thrashing.

[STATUS]

I would always use a flex pipe, single or twin.

agreed a flex pipe fitted into a front pipe is far cheaper than a new manifold.

[sl33py]

What about solid pipes on the RB25DET from AFM to turbo? I think the flex in the rest of the stock piping does the equivalent job of the flex here right?

I had a Civic with a solid pipe instead of the flex pictured above - it meant a small exhaust leak and a terrible whizzing noise until I got some flex put back in there... which is when they noticed a blocked up home-made oil return on the sump... They reckoned it had been turbo'd, or at least attempted, and then reverted back to normal!

[R32gts-t]

super old thread revival here!

anyone know where to buy/order some good quality 3 inch flex pipe?

[and3_3]

any exhaust shop has them

[R31Nismoid]

Can i be the first to say an exhaust shop Greg?

I've really never seen much of a quality difference between flex pipes of my various exhausts and they all came from difference places so there must be some sort of 'way its done' out there

[R32gts-t]

haha, No Ash, you can be second!

i've orderred one from xforce, 3inch $120 + $12 delivery.

thanks guys...

[mad082]

if you are having serious engine movement issues (and aren't running big power) i would be looking at the cause of it (shagged engine mounts) rather than putting a flex pipe in.