Flex or no flex

dwreck30 · Post by **dwreck30** » Thu Feb 16, 2006 2:57 am

I need a new up-pipe and I am looking at getting a used HKS pipe. My question do I really need the flex secton like to stock one or not? Thanks.

BAC5.2 · Post by **BAC5.2** » Thu Feb 16, 2006 4:20 pm

You should have a flex. Yes.

If the pipe is real cheap, weld a flex into it!

dwreck30 · Post by **dwreck30** » Fri Feb 17, 2006 2:09 am

Ok, but why do HKS, Invidia, TXS, and most other bigger companies offer no flex sections? What are the downsides of no flex?

magicmike · Post by **magicmike** » Fri Feb 17, 2006 5:00 am

whats wrong with your current up-pipe? is it cracked? why do you need it replaced?

dwreck30 · Post by **dwreck30** » Fri Feb 17, 2006 5:35 am

Yeah there is a crack at the bottom of he flex section.

BAC5.2 · Post by **BAC5.2** » Fri Feb 17, 2006 5:41 am

Why don't they do it? I dunno. Maybe costs or manufacturing problems or fear of leaking.

I'd like to have a flex, personally.

magicmike · Post by **magicmike** » Sat Feb 18, 2006 5:29 pm

I dont see any need for a flex in that piece other than to help line it up with the turbo. the exhaust manifold is fixed to the block, the up-pipe is fixed to turbo which is fixed to the block by the support bracket and the down-pipe is fixed to the turbo and the trans. The up-pipe doesn't need to flex or move under and sircumstance once installed. it moves as a whole with the engine and trans.

vrg3 · Post by **vrg3** » Sat Feb 18, 2006 5:50 pm

You're neglecting the effect of heat, Mike. The engine and transmission are made of aluminum and get up to around 200 degrees. The exhaust manifolds are made of cast iron and get up to around 1500 degrees. The uppipe is made of stainless steel and also gets up to around 1500 degrees. They're not going to just move as a whole.

I say you should definitely have a flex section.

BAC5.2 · Post by **BAC5.2** » Sat Feb 18, 2006 6:32 pm

Also, I just remembered. The new TurboXS Uppipes have flex sections in them. Beefy awesome ones too!

Innovative Tuning · Post by **Innovative Tuning** » Sat Feb 18, 2006 8:55 pm

BAC5.2 wrote:Also, I just remembered. The new TurboXS Uppipes have flex sections in them. Beefy awesome ones too!

Actually they switched because now customers can't say it doesn't fit right when they install it wrong...and frankly I can't blame them.

The cast iron ones never failed. I keep one here for me incase I ever need it for one of my cars.

I recommened ones without flex as long as they're made well. The flex joints will inevitably fail and leak at some point. Yes even the high dollar ones like the APS. I've seen it WAY too many times.

The Scooby · Post by **The Scooby** » Sun Feb 19, 2006 2:44 am

do all years have a flex up-pipe? i was looking at mine the other day and i dont think i saw a flex in it... or is it right up under the turbo?

Psychoreo · Post by **Psychoreo** » Sun Feb 19, 2006 3:27 am

i don't think so. the 92 turbo motor i got from Blackbart (almost running) doesn't have a flex.

Post by **Legacy777** » Sun Feb 19, 2006 4:09 am

There's a flex. The 93 motor I have has a flex.

BAC5.2 · Post by **BAC5.2** » Sun Feb 19, 2006 7:27 am

Innovative Tuning wrote:Actually they switched because now customers can't say it doesn't fit right when they install it wrong...and frankly I can't blame them.

The cast iron ones never failed. I keep one here for me incase I ever need it for one of my cars.

The cast iron ones had some problems. That's why they stopped making them

The uppipes had some manufacturing problems in Australia. They were sorted out, but for a while one of their guys was welding the flexes into them.

Then the problem got solved, and the flex was welded into the pipe.

vrg3 · Post by **vrg3** » Mon Feb 20, 2006 12:19 am

All OEM uppipes have flex joints, for the reasons I gave above. The heat shields cover them up.

93forestpearl · Post by **93forestpearl** » Mon Feb 20, 2006 6:00 am

I bought a flex pipe to put on the up-pipe I build. I don't like the idea of possibly having the gaskets leak all the time. Unless I fab one, I'm gonna be without a brace on the turbo so I want some give there, with the snail only held up by all the piping.

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Flex or no flex

Flex or no flex