Is a flex tube 100% necessary on the DP?
 

I searched and was surprised not to see anything on this.

I have a feeling the answer is yes. But i'm absolutely out of cash at this point and cannot afford to buy one right now.

Even if I can just get by without one for a few weeks while i'm job hunting/get a paycheck. I can weld one in later no problem.

I really just dont see how a downpipe could possibly last without one though...

I don't have one on mine so far so good.

Fucking awesome. That is exactly what I wanted to hear.

my friend didn't put one on his. couldn't wait 1 day for our usual exhaust guy to work on it. so he got it done somewhere else and the next day he got on it and cracked his $1000, 3month wait, custom exhaust manifold.

so if you have to drive it like that, don't floor it!

you absolutely HAVE to have a flex pipe somewhere... but you'll be ok for a little while without one. My exhaust broke one or twie a year withoput one, for around 3 years...

yea i would recommend one, my friend didn't have one on his 240 and he broke an exhaust manifold a few times without one

bleh...

For what its worth I plan to get one on mine as well. I definitely don't think its good that I don't have one now. The local metal place wanted to charge me 60 for a tiny ass 4" flex section. I told them to stick it up their ass. Once I find a cheap one I'll weld it in.

I recommend you do the same.

I don't have one. Greddy cast manifold, greddy turbo, the used kit came with a custom 2.5" DP, bolted to 2.5" mid pipe that's welded to a 2.5" cat, then VTA. I had more pipe after the cat going to a magnaflow muffler for about a year, and so far about 1.5 year without the muffler, a dozen or more track days, no cracking.

I think its needed, especially the way the BP shakes, its not the smoothest engine in the world

no to all of these.

I've had zero flex pipe on my home built system for so many miles it's not even funny. I put my turbo on in 2004 or something?

Just dont use a hanger between the turbo and the stock hanger thats under about where your asscheeks are. DEFINITELY DO NOT bolt it to the transmission!

Mazda Comp engine mounts help too.

Please tell me why not.

Kinda curious about that myself. My DP is coupled to the bellhousing via a U-bolt and a bracket, with the flex section just aft. Or at least it was until the U-bolt fell off last week. Made a really horrible sound just before it hit the pavement. Still, no problems after 3 years. Just glad I didn't hole a tire on it.

But yeah, you need a flex section somewhere or else your manifold will break into three pieces and your dick will fall off.

Im running my Absurdflow with no flex. Paul's Machine has no flex. No problems whatsoever.

I rest my case. :D

Ouch.

I am pretty sure none of the 'street' manifolds I have done have a flex section except for Evan's MSM; everyone else was too cheap ;) None of them have cracked.

I now require them on the 'track' downpipes I do.

Make sure you fully weld on the inside of the downpipe flange and do at least strips on the outside of the flange, if not also all the way around.

Careful Anton, I don't know if ^ knows what he's talking about.

Seriously dude I was just thinking that. This turbotim guy doesn't know his ass from a hole in the ground when it comes to fabrication. ;)

Thanks guys, i'm going to fearlessly procede without a flex pipe and will make sure I have one in place before my first track day next season. This saves me some cash for sure that can go toward some bitchin hardware or something.

I have a bad case of not reading the entire thread before posting. so...

My very first downpipe (racing mazda for the greddy kit) didn't last long when attached rigidly to the bell housing. Maybe a few weeks? That stuff needs to move around with heat, especially stainless DP's. If running no exhaust, a not so rigid bracket would be a good idea towards the end of the DP, I'd use one of those reinforced hard rubber exhaust hanger strap things and a U clamp.

Careful not to seize your Motec muffler bearings though