DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Is a flex tube 100% necessary on the DP?

Thread Tools
 
Search this Thread
 
Old 11-10-2009, 07:00 PM
  #1  
Elite Member
Thread Starter
iTrader: (8)
 
wayne_curr's Avatar
 
Join Date: Aug 2007
Location: Bellingham, Wa
Posts: 2,712
Total Cats: 4
Default 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...
wayne_curr is offline  
Old 11-10-2009, 07:02 PM
  #2  
VladiTuned
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 35,821
Total Cats: 3,481
Default

I don't have one on mine so far so good.
18psi is offline  
Old 11-10-2009, 07:05 PM
  #3  
Elite Member
Thread Starter
iTrader: (8)
 
wayne_curr's Avatar
 
Join Date: Aug 2007
Location: Bellingham, Wa
Posts: 2,712
Total Cats: 4
Default

Originally Posted by 18psi
I don't have one on mine so far so good.
******* awesome. That is exactly what I wanted to hear.
wayne_curr is offline  
Old 11-10-2009, 07:24 PM
  #4  
Senior Member
iTrader: (1)
 
spoolin2bars's Avatar
 
Join Date: May 2008
Location: south texas
Posts: 1,415
Total Cats: 10
Default

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!
spoolin2bars is offline  
Old 11-10-2009, 07:31 PM
  #5  
Senior Member
 
airbrush1's Avatar
 
Join Date: Nov 2005
Location: Baltimore Maryland
Posts: 1,038
Total Cats: 9
Default

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...
airbrush1 is offline  
Old 11-10-2009, 07:43 PM
  #6  
Newb
 
WildMride's Avatar
 
Join Date: Jan 2008
Location: Rockville, MD
Posts: 21
Total Cats: 0
Default

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
WildMride is offline  
Old 11-10-2009, 07:44 PM
  #7  
Elite Member
Thread Starter
iTrader: (8)
 
wayne_curr's Avatar
 
Join Date: Aug 2007
Location: Bellingham, Wa
Posts: 2,712
Total Cats: 4
Default

bleh...
wayne_curr is offline  
Old 11-10-2009, 07:46 PM
  #8  
VladiTuned
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 35,821
Total Cats: 3,481
Default

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 *** 4" flex section. I told them to stick it up their ***. Once I find a cheap one I'll weld it in.

I recommend you do the same.
18psi is offline  
Old 11-10-2009, 07:48 PM
  #9  
Cpt. Slow
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 14,175
Total Cats: 1,129
Default

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.
curly is offline  
Old 11-10-2009, 07:50 PM
  #10  
Elite Member
iTrader: (1)
 
Full_Tilt_Boogie's Avatar
 
Join Date: May 2009
Location: Jacksonville, FL
Posts: 5,155
Total Cats: 406
Default

I think its needed, especially the way the BP shakes, its not the smoothest engine in the world
Full_Tilt_Boogie is offline  
Old 11-10-2009, 08:27 PM
  #11  
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,338
Total Cats: 573
Default

Originally Posted by spoolin2bars
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!
Originally Posted by airbrush1
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...
Originally Posted by WildMride
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
Originally Posted by Full_Tilt_Boogie
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.
y8s is offline  
Old 11-10-2009, 08:35 PM
  #12  
VladiTuned
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 35,821
Total Cats: 3,481
Default

Originally Posted by y8s
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.
18psi is offline  
Old 11-10-2009, 08:40 PM
  #13  
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,019
Total Cats: 6,587
Default

Originally Posted by 18psi
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.
Joe Perez is offline  
Old 11-10-2009, 08:52 PM
  #14  
Senior Member
iTrader: (1)
 
ArtieParty's Avatar
 
Join Date: Sep 2007
Location: Trenton, NJ
Posts: 1,118
Total Cats: 0
Default

Im running my Absurdflow with no flex. Paul's Machine has no flex. No problems whatsoever.
ArtieParty is offline  
Old 11-10-2009, 09:00 PM
  #15  
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,019
Total Cats: 6,587
Default

Originally Posted by Joe Perez
But yeah, you need a flex section somewhere or else your dick will fall off.
Originally Posted by ArtieParty
Im running my Absurdflow with no flex.
I rest my case.
Joe Perez is offline  
Old 11-10-2009, 09:10 PM
  #16  
Elite Member
iTrader: (9)
 
TurboTim's Avatar
 
Join Date: Jun 2006
Location: Chesterfield, NJ
Posts: 6,892
Total Cats: 399
Default

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.
TurboTim is offline  
Old 11-10-2009, 09:11 PM
  #17  
Cpt. Slow
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 14,175
Total Cats: 1,129
Default

Careful Anton, I don't know if ^ knows what he's talking about.
curly is offline  
Old 11-10-2009, 09:13 PM
  #18  
Elite Member
Thread Starter
iTrader: (8)
 
wayne_curr's Avatar
 
Join Date: Aug 2007
Location: Bellingham, Wa
Posts: 2,712
Total Cats: 4
Default

Originally Posted by curly
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 *** 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.
wayne_curr is offline  
Old 11-10-2009, 09:14 PM
  #19  
Elite Member
iTrader: (9)
 
TurboTim's Avatar
 
Join Date: Jun 2006
Location: Chesterfield, NJ
Posts: 6,892
Total Cats: 399
Default

Originally Posted by Joe Perez
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.
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.
TurboTim is offline  
Old 11-10-2009, 09:16 PM
  #20  
VladiTuned
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 35,821
Total Cats: 3,481
Default

Careful not to seize your Motec muffler bearings though
18psi is offline  


Quick Reply: Is a flex tube 100% necessary on the DP?



All times are GMT -4. The time now is 04:57 AM.