pipe bending

[AreSTG]

Alright, I'm finally getting annoyed enough at my downpipe vibrating on my ACD. Not only did it start to cause damage(before a hammer altered the flex portion of the DP), but when the engine torques from idle (from a stop) it makes a fart sound vibrating on the ACD. I'd liek to fix this.

The hobby shop on base does not have pipe bending capabilaties, and the TIG has been broken for like 9 months. However they do have a torch and a bigass vise.

Knowing that I have access to the vise, torch, and sometimes seemingly endless supply of specialty tools, does anyone have any knowledge on redneck pipe bending? I'm looking to make a minor bend in the pipe (technically two bends) withought an actual pipe bender. Hopefully somone has done this and can give me some suggestions, it's a pretty minor adjustment that will bring me great joy in life...

Thanks a bunch!

[BOOSTX2]

It will kink and defeat the purpose of a aftermarket D.P... To do it right you should
buy the correct D.P.
The correct way to do it would be to take a Stainless j or u Bend of the same
thickness and diameter and cut the parts out of that..
Then cutout a section of the DP and splice in the 3 part assembly you built from
the J or u bends and thats it..
That would cost way more than a new D.P. that is for a ACD evo..
Or you could take a hammer and put a dent to clear the ACD but you will change
the flow carateristics..

[AreSTG]

It will kink and defeat the purpose of a aftermarket D.P... To do it right you should
buy the correct D.P.
The correct way to do it would be to take a Stainless j or u Bend of the same
thickness and diameter and cut the parts out of that..
Then cutout a section of the DP and splice in the 3 part assembly you built from
the J or u bends and thats it..
That would cost way more than a new D.P. that is for a ACD evo..
Or you could take a hammer and put a dent to clear the ACD but you will change
the flow carateristics..


kink? that's what the torch is for right? I'm not trying to make a stright pipe make a 90 degree turn, just make the dowards part "lean" about 1/2" -3/4" to the driver side of the car, and though not neccisary, once past the ACD make is go a little to the passenger side (to make up for the new change).

I'm wondering how a small change is gunna kink. I'm not even really wanting to make a noticable bend on one spot, more a general "lean" (for lack of a better word) to the driver side.

[IlovemyevoIX]

did you use a VIII DP on a IX?

[BOOSTX2]

The metal has to give somewhere thus kinking...Hey thats kinky :lol:
Your aftermarket DP is mandrel bent..This means same pipe diameter even around
the bends..
That and the larger diameter tubing is why the madrel bent DP flows better..
put in a flat spot or kink and the flow will change..
It might only be slight so maybe your okay.. But it will def. deform the tube even if
you heat it..

[AreSTG]

The metal has to give somewhere thus kinking...Hey thats kinky :lol:
Your aftermarket DP is mandrel bent..This means same pipe diameter even around
the bends..
That and the larger diameter tubing is why the madrel bent DP flows better..
put in a flat spot or kink and the flow will change..
It might only be slight so maybe your okay.. But it will def. deform the tube even if
you heat it..


hmm, you give me a new thought than. Metal contracts when heated correct? Heat the side i want it to Lean towards it contracts there, and maybe a love tap that direction and i'm set... yea/nay?

[AreSTG]

I guesse my best bet might be replacing the flex portion of the pipe with a solid piece.Â* Than being able to aim it just enough over the direction I need, and reall IMO just being a straight pipe rather than the flex pipe, it would fit even aimed EXACTLY the same.Â* Reason being the flex portion has a much larger OD than the rest of the DP.

Thing is, like I said before the TIG has been broke a while on base, BUT they did say it's inaÂ* shop to see if it can be repaired or if they need a new one.Â* Much better than all the time it sat there broke.

here it is, bought in 05
http://ttp-engineering.com/catalog/images/TTPDownpipe.jpg

[BOOSTX2]

With some luck... yay, Stainless warps like crazy when welding in comparison to
steel so with some luck...But its going to be tough to make it give just so..
I have bee doing metalfab 20+ years and have seen many attempts but very few
with good outcome..But hey I am a perfectionist so I'm real picky about my project..

[AreSTG]

any idea where is a good source of generic stainless pipe? not in bulk that is. Gunna tray a torch to shrink one side, and if thats not enough replace the flex portion. Hey, i still always have my stock DP (though it has no bung for zeitronix.....)

If you have any pointers for me since you've done fab please share. I could ask my dad but he's all CNC milling. Never did welding.

[BOOSTX2]

I guesse my best bet might be replacing the flex portion of the pipe with a solid piece.Â* Than being able to aim it just enough over the direction I need, and reall IMO just being a straight pipe rather than the flex pipe, it would fit even aimed EXACTLY the same.Â* Reason being the flex portion has a much larger OD than the rest of the DP.

Thing is, like I said before the TIG has been broke a while on base, BUT they did say it's inaÂ* shop to see if it can be repaired or if they need a new one.Â* Much better than all the time it sat there broke.

here it is, bought in 05
http://ttp-engineering.com/catalog/images/TTPDownpipe.jpg

That sounds better than the other plan..But TIG is required..
Or you could buy a new one.. than sell that one to someone with a non-ACD evo..
That way you dont have to cut & weld at all and you recoup most of the $ spent on a new D.P....
The non ACD guy (like me) is happy and you have a new D.P. that fits nice.. Win/Win 8)

[AreSTG]

no one will wanna buy mine I beat it with a hammer (on a external part that has nothing to do with flow, trust me).

holy crap I'm filling thsi thread up quick with posts. Â*BUT i thought of something else. Â*You mentioned kinking when I bend it. Â*If I rememebr the pipe correctly, I think the flex portion makes contact partially due to raising up too far to clear the bar (one that bolts on with 3 bolts). Â*It clears that with PLENTY of room.

Would i still have the same problem with kinking if I am UNbending the pipe? Â*I'm thinking that sounds alot safer.

[BOOSTX2]

Bend/unbend when the material moves it will give somewhere..
The more it moves the more deformation.. The 1,000 dollar qustion is how much
deformation will occur when you moved it enough..

[DoggDicker]

Two options...beat it with a hammer, or buy a Tanabe 2.75 and sell the one that's on the kaa right now...recouping some of the money spent for the new one...just my opinion though...g/l...

DD

[esco]

I'd buy a new dp, but you can see if drag'n motorsports is still around there in Yuba city/wheatland. Havent been there to the shop(s) in ages.

[AreSTG]

I'd buy a new dp, but you can see if drag'n motorsports is still around there in Yuba city/wheatland. Havent been there to the shop(s) in ages.


never heard of it. I know an exhaust shop, but their service was slow as shittt, and i could have welded the bung better myself.

[MarkSAE]

I'm guessing the downpipe you currently have doesn't utilize the factory donut gasket, hence the need for a flex section in the first place. You don't want to get rid of the flex section cuz it'll take away any allowable movement of the entire exhaust. Your whole exhaust will be cantilevering off your o2 housing.. something's gonna give.

If you got access to a TIG welder, you can probably just buy a SS u-bend. Or you can just buy another DP.. they seem to be pretty cheap nowadays.. check e-bay.

[Matz]

Tim, you're probably going to save time and wasted $ trying to fix it for cheap, if you just buy a new DP... You can probably even find used ones here or on evom. Just my 0.02.

[trinydex]

It will kink and defeat the purpose of a aftermarket D.P... To do it right you should
buy the correct D.P.
The correct way to do it would be to take a Stainless j or u Bend of the same
thickness and diameter and cut the parts out of that..
Then cutout a section of the DP and splice in the 3 part assembly you built from
the J or u bends and thats it..
That would cost way more than a new D.P. that is for a ACD evo..
Or you could take a hammer and put a dent to clear the ACD but you will change
the flow carateristics..

this is what's known as welding pie cuts.

http://img.photobucket.com/albums/v169/Philipdalgity/Evo/Exhaust/IMG_1540.jpg

http://img.photobucket.com/albums/v169/Philipdalgity/Evo/Exhaust/IMG_1533.jpg

[EFIxMR]

as someone who does ss tig welding and fab, i'd just advise you to just get a new dp that fits. anyone who can properly do the job, is going to charge you more for labor and materials to mod your current dp.

of course you can half ass it and get a regular muffler shop to do it for you, but mig welding ss with regular steel wire, isn't going to last and won't be pretty.

[SpeedElement]

this is part of reasons why all exhaust systems and downpipes are not created equal.

Some vendors on EVOM simply like to hype up their exhaust products and provide false informations just to make that quick buck.

If you are not pushing well over 400whp, my suggestion is get a 2.75" downpipe and you will not have any issues with fitment and they perform just the same as any 3" dp.

[dl_EVO]

I'm very happy with the fitment of my Tanabe 2.75" DP. The fitment and clearance is superb!

[AreSTG]

well. They say the welder is fixed and they'll pick it up soon, so I'm going to go back to the stock DP and just put a bung for my o2 sensor. Since I'm running the stock cat for now I am just annoyed and gunna run the stock DP since it goes back to stock size at the cat anyway... than eventually buy a 100cel cat, use my TP that sits in the garage to make it work and put a tanabe on at the same time.

Can somone tell me what meterial the stock DP is?