Why you should have a flex section on your downpipe

[BigRand]

Okay so a while back I posted a thread explaing why you should have a flex pipe, and I showed a crack in my downpipe.

Well after I peiced the old one back together and put a flex section in (but too far away from the 90 bend). I also re routed my dump tube.

so all that worked for awhile, except for the flex section being placed in the wrong spot, and the dump tube was a bit off in where it was welded.

Even though the pipe was braced to the block with the polyurathane motor mounts it just shakes so much that I developed another crack. After touch welding it at a friends house I let my anger get to me with a guy purposely getting in my way and staying in my way while crosssing the street, and in stead of using my horn I let my tires do the talking and screaming.

LONG STORY SHORT, this is the result of:

1) not having flex pipe on your down pipe in the right place
2) polyurathane motor mounts
3) an improperly welded rerouted dump tube


Well I've got the hook up on a Stainless Steel custom made 3" downpipe thanks to horsepowerconnection.com I'll post pics of the finished product when it's done, but for now.....

P.S. This one goes out to Xmasta and his Street Source Manifold.

 

[Locke]

that sucks man. having thoughts of dropping the turbo setup yet?

hope you get it figured out, nice and sturdy like.

 

[Blitzeclips]

Wow Rand tough luck. You'd think the car would let up on you after cracking the first pipe.

No offense, but the metal for that downpipe looks pretty thin.

Also, where is exactly is your flex section? I have one, but you are scaring the shit out of me still...

 

[BigRand]

Okay here is the low down....the star down pipe is made out of some really thin mild steel. And after heating and cooling so many times it can only last so long (especially with all the stress of the motor mounts and most importantly the slightly off wastegate dump tube).

So no I'm not dropping the turbo system, I've been waiting for this to happen and it sorta came at the right time yet at the wrong time. Its right in between my bday and christmas all though I wanted tires those are just gonna have to wait now. I'm also traveling for this coming week and so the guys making the new downpipe said they could look after my car while I'm gone and have it ready when I get back.


P.S. My flex section was used as a test pipe for now The guy who was helping me fix it was in a rush and I guess the star downpipe has a couple curves he didn't want to mess with and didn't want to re do my wideband bung that was there.

I can't complain too much, I'm getting a really good deal on a full 3" downpipe and wastegate dump reroute all in stainless steel.

 

[Blitzeclips]

I can't complain too much, I'm getting a really good deal on a full 3" downpipe and wastegate dump reroute all in stainless steel.

So how much are you paying for it? I needed to remove my AC charger and fab a new one too. Well, atleast so it could move around that object. I paid $300 for 3" back to the CAT. It was a pretty nice amount, on top of my exhaust which was $220. So my entire exhaust set-up is around $500, but I LOVE IT. Custom bend, flex section, bungs, no cat, 3" back, well worth the money...

Are you going 2.5--->3 or 3-----> tippidy tip ?

SOrry if I didn't specify earlier, but about how far down was your flex section from the exhaust manifold?

 

[420Adriver]

Man that sucks, I am sure it will look 1000 times better though with the new dp.

 

[Talon ESI-T]

Randy, the dump tube is not the culprit here, its the flex section location. I have routed my dump tube liek that and when solid it cracked the same way. Once a flex section was added it was fine. The 3" I made is also fine with a flex section and the dump tube routed the same way.

 

[BigRand]

I know but the flex section is a big part of it because It is (about where the cat would be on a normal 2g.) But I know the dump tube played into it because when tightening the bolts for the wastegate and the turbo they were always off a little bit making it real hard to bolt it back up, and put a lot of stresss on it. But I believe that the flex section was the main kicker here.

 

[Blitzeclips]

Wow, all the way back where the CAT is? That IS a wierd location... I think mine is around 2 feet before that...

 

[BigRand]

yeah it was laziness upon the exhuast shop that fabbed it up for me, and I really didn't have time thanks to school to do something about it, now I have no choice.

 

[Talon ESI-T]

IF the Dump tube had anything to do with it, you would have cracked between the dump and turbo.

 

[BigRand]

Okay so here is an update

Here is my new Full 3" downpipe next to my old one.

You can see where the old flex section was, and you might also notice that I don't have one on the new one.

They were trying to save me some money, and said the another main reason why I was having so many issues was because of how thin the mild steel was used to make the old one.
I've been told that if something does break though they would put a new flex in there and weld up whatever I needed for free.

there is about 14hrs of labor that went into making this downpipe @50/hr that is $700 plus the SS steel material required to make it was about $250-$300, that is about $1000...I won't tell you what I paid for it but it lets just say I'd really really really like to thank the guys at horsepowerconnection.com and as much as I don't like stickers....there will be one placed on the rear hatch window of my car.

Man I wish I new how to tig weld.....

 

[CTP_MADDOG]

if that took 14 hrs to make, there is a problem.. and where is the flex on that new dp?

 

[Locke]

For what that could have cost you, you could have bought a small welder and a couple spools of wire to learn on. I use a little $500 gas-less Lincoln Electric. Has a horribly short duty cycle. About a piece of crap but it gets the job done.

Anyway, looks good though. Keep the stompin' boots polished and laced, in case it does break.

 

[JohnEagle]

i am sure the problem is the flex joint but have you checked your engine and trans mounts for wear ?

 

[4UH8ERS]

Okay so here is an update
They were trying to save me some money, and said the another main reason why I was having so many issues was because of how thin the mild steel was used to make the old one.
I've been told that if something does break though they would put a new flex in there and weld up whatever I needed for free.

Well get a box ready, because without a flex section you might be sending them your manifold next. Just not worth the risk, flex sections are not that expensive, and any exhaust shop can put one wherever you would like.

 

[BoostedinSoFla]

14 hrs to make that and there's still a possibility that the same thing can happen again. I would've had them just put the flex section in there to begin with. I hope you paid less then half of that price btw.

 

[Rob10_99]

he will cut it an insert where the best spot is(most room?) for the flexy,
most flex pipes are somewhere near the oil pan,
if you immagine your engine tilting(or just rev the motor) and it should be best placed on the axis that will suit it best, usually thats under the pan or closer right?

anyone know anything more specific on this?

 

[Blitzeclips]

I told ya that metal was too thin! Looked like re-inforced construction paper..

Anyways, the exhaust looks good, I'm glad you got the hook up on it. Seems like you've had your share of exhaust issues. Nice to see you get a break/deal.

ROB- As for your question, yes around where the oil pan is would be my guesstimate for flexpipe location. Mine is located right around that area, seems to be ideal for any bending of flexing from the motor vibes or bumpy driving.

 

[4UH8ERS]

he will cut it an insert where the best spot is(most room?) for the flexy,
most flex pipes are somewhere near the oil pan,
if you immagine your engine tilting(or just rev the motor) and it should be best placed on the axis that will suit it best, usually thats under the pan or closer right?

anyone know anything more specific on this?

Yes, that would work fine. If you place the flex section anywhere after the 90 bend but before the cat then you should be fine.

 

[BigRand]

i am sure the problem is the flex joint but have you checked your engine and trans mounts for wear ?

Yeah I've got these energy suspension polyurathane mounts to begin with which didn't help the other downpipe at all....my motor never or hardly moves at all. If I take out the mounts
A flex section will be going in at the same time.

I told ya that metal was too thin! Looked like re-inforced construction paper..

, so true......gotta love STAR products.