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Engine Specific Info and Questions => IDI Engine => Topic started by: dankcorey22 on October 23, 2010, 08:29:42 pm

Title: homemade 2.5" DP
Post by: dankcorey22 on October 23, 2010, 08:29:42 pm
How hard is it to make a 2.5" DP? I know people has done it, but im wondering what angles and bends they used.
Or what did they go by? The stock downpipe?

its on a 1.6td

Could someone tell me references to making one. i don't want to pay 300 for one.
Title: Re: homemade 2.5" DP
Post by: gribur on October 23, 2010, 08:35:30 pm
I have a 1.9td and am definitely interested in any info out there.  No way I can cough up that much cash either.  Someone please give out some info, you could save us all a ton of cash. cheers guys!
Title: Re: homemade 2.5" DP
Post by: Vincent Waldon on October 23, 2010, 08:54:48 pm
A mandrel-bent j-bend and away you go:

http://www.vwdiesel.net/forum/index.php?topic=14003.0
Title: Re: homemade 2.5" DP
Post by: KinseyJ on October 24, 2010, 01:38:33 am
I think i spent about 75 buck for some mandrel bents online, my downpipe was a little bit more complicated cause i had a g60 intake manifold and i flipped my turbo and exhaust maifold upside down, so it came out on the other side and had to clear my rear motor mount. if you can get your hands on a wire feed welder and a metel chop saw you will be set. took me one evening to get mine all built. i would post pics but i'm not sure how. good luck
Title: Re: homemade 2.5" DP
Post by: Smokey Eddy on October 24, 2010, 02:34:09 am
i used a 180 and a 90
cut up the 180 to make it work. dont remember exactly what angles but you can figure it out pretty easily. then the 90 is to direct it backwards.
Title: Re: homemade 2.5" DP
Post by: dankcorey22 on October 24, 2010, 01:41:11 pm
i think the hardest part will be keeping clear of the shifting links or the transmission mount right?
Title: Re: homemade 2.5" DP
Post by: 81 vw pu on October 24, 2010, 06:23:25 pm
Here's a link for a mk1.

http://www.vwdiesel.net/forum/index.php?topic=19113.msg143382#msg143382
Title: Re: homemade 2.5" DP
Post by: dankcorey22 on October 24, 2010, 06:48:44 pm
Here's a link for a mk1.

http://www.vwdiesel.net/forum/index.php?topic=19113.msg143382#msg143382


Thats exactly what i needed! thanks man!

I made my flange but i think i got some metal that was too thin:( after seeing what they used on theirs. I spent alot of time on it too. Wonder if i can buy just the flange already made to fit 2.5" pipe
Title: Re: homemade 2.5" DP
Post by: theman53 on October 24, 2010, 07:23:46 pm
http://weirtech.ca/catalog/product_info.php?cPath=13_28&products_id=178
Title: Re: homemade 2.5" DP
Post by: Smokey Eddy on October 24, 2010, 10:09:30 pm
The hardest part for me was making it with enough clearance for when the engine torques the pipe doesn't hit the underside of the car.
its a tight squeeze with a power steering rack.
Title: Re: homemade 2.5" DP
Post by: dankcorey22 on October 25, 2010, 09:33:35 am
Lucas that the wrong one. im talking about the flange on the turbine housing.

And my car doesnt have power steering so im good with that!
Title: Re: homemade 2.5" DP
Post by: theman53 on October 25, 2010, 03:40:35 pm
Turbo Outlet???
Scroll down in the link or click on VW on the side. They have what you need I am sure.
Title: Re: homemade 2.5" DP
Post by: dankcorey22 on October 25, 2010, 07:00:05 pm
oh yeah the K03 outlet. I just didnt scroll down far enough. thats pretty cheap! and cheap!
Title: Re: homemade 2.5" DP
Post by: R.O.R-2.0 on October 26, 2010, 09:35:34 am
easiest way to build a downpipe on a mk1 car is to install a VNT on it, then there is only 2 90* bends needed, one directing the exhaust down, and one directing it back..

(lol  8))
Title: Re: homemade 2.5" DP
Post by: regcheeseman on October 26, 2010, 03:35:25 pm
Quote
easiest way to build a downpipe on a mk1 car is to install a VNT on it, then there is only 2 90* bends needed,

Where did you get the flange for the VNT?
Title: Re: homemade 2.5" DP
Post by: R.O.R-2.0 on October 26, 2010, 04:59:22 pm
Quote
easiest way to build a downpipe on a mk1 car is to install a VNT on it, then there is only 2 90* bends needed,

Where did you get the flange for the VNT?

made it, crudely torch cut (with an extremely dirty, worn out torch tip) some steel, and then i layed it on my surface grinder to true it up a tad bit. then i use cut up a Mitsubishi G54B exhaust manifold gasket for the turbo gasket, just cut the mitsu gasket into 4 pieces, then you got 4 exhaust gaskets! nothing special, but my downpipe has worked fine for as ling as ive had it on the car. it cracked one time, but then i reinforced it way good.. thought about building a mount to the block for it.
Title: Re: homemade 2.5" DP
Post by: dankcorey22 on October 26, 2010, 07:51:27 pm
easiest way to build a downpipe on a mk1 car is to install a VNT on it, then there is only 2 90* bends needed, one directing the exhaust down, and one directing it back..

(lol  8))

Right im gonna trade my K03 turbo and manifold for anyone with a vnt-15! any offers?!  :D PLEASE  :D
Title: Re: homemade 2.5" DP
Post by: rallydiesel on October 26, 2010, 07:52:48 pm
vnt-15's can be had for pretty cheap over on tdiclub.
Title: Re: homemade 2.5" DP
Post by: R.O.R-2.0 on October 27, 2010, 04:45:12 am
my vnt was a VERY good price, FREE!
Title: Re: homemade 2.5" DP
Post by: dankcorey22 on October 27, 2010, 09:26:18 am
I had a good one off of my tdi but i sold it for 300 to help with the vnt 17/22
Title: Re: homemade 2.5" DP
Post by: derekp on October 28, 2010, 08:23:03 am
I built a down pipe for my sons 16V ABA turbo conversion project (ok hold on - its relavant)
I bought mandrel bends for that from
http://www.mandrel-bends.com

They have a lot on their website and also were very helpful on the phone
They have silicon connectors and elbows too.
And I find their prices to be reasonable

The problems I encountered there were fitting things so they wouldnt interfere with the shift linkage
Title: Re: homemade 2.5" DP
Post by: R.O.R-2.0 on October 28, 2010, 10:00:52 am
I had a good one off of my tdi but i sold it for 300 to help with the vnt 17/22

too bad you didnt keep it for the jetta, would have been the turbo to have, or just take the 17/22 off your TDi! lol...
Title: Re: homemade 2.5" DP
Post by: rumbling_caddy on October 28, 2010, 10:47:08 am

  Here's my cheapy 2.5" exhaust.  I took an original Mk1 exhaust piece belown the toilet bowl flange local NAPA muffler guy to use as a template.

He cut off the flange and mad this piece for me:

This is before the flange was fully welded.
(http://farm5.static.flickr.com/4109/4985348340_14c3029034_z.jpg)

Then I just pieced together the rest of the exhaust with off-the-shelf slip on 2.5" pipes and ran two mufflers in series.  One cheap muffler and a Borla is got off CL.  Spent a total of about $170.

(http://farm5.static.flickr.com/4128/5008617924_8abc83becd_z.jpg)

[/IMG]http://farm5.static.flickr.com/4085/5008011955_9ba99b99cd_z.jpg[/IMG]

Is it a bad idea to keep the stock 1.6TD cast iron downpipe with the toilet bowl flange? It didn't seem to be restrictive to me and of course it's sturdy.


Title: Re: homemade 2.5" DP
Post by: dankcorey22 on October 28, 2010, 03:39:20 pm
Haha! i sold that turbo before i got my TD. Or else i would have keep it! i dont know how/where i would run the vacuum hose for the VNT actuator

plus im not trying to make my TD a racer  :P I already have a car for that "TDI"  ;) lol

I had a good one off of my tdi but i sold it for 300 to help with the vnt 17/22

too bad you didnt keep it for the jetta, would have been the turbo to have, or just take the 17/22 off your TDi! lol...
Title: Re: homemade 2.5" DP
Post by: AudiVWguy on October 28, 2010, 08:06:07 pm
Don't limit your thinking to 2.5 inch, when it comes to getting rid of diesel exhaust, bigger is better. I was able to fit a 3 inch off the turbo. Faster spool-up and lower EGT's .
Cheers,
-JB
Title: Re: homemade 2.5" DP
Post by: R.O.R-2.0 on October 29, 2010, 09:26:35 am
Haha! i sold that turbo before i got my TD. Or else i would have keep it! i dont know how/where i would run the vacuum hose for the VNT actuator

plus im not trying to make my TD a racer  :P I already have a car for that "TDI"  ;) lol

I had a good one off of my tdi but i sold it for 300 to help with the vnt 17/22

too bad you didnt keep it for the jetta, would have been the turbo to have, or just take the 17/22 off your TDi! lol...

i never hooked up the vain control.. most people used linkages hooked to the injection pump throttle lever.. even with no vain control, it still spooled like a MOFO..
Title: Re: homemade 2.5" DP
Post by: dennis on October 29, 2010, 03:01:54 pm
YOu can find a lot of decent mandrell bends at most exhaust shops. A lot of cutting and welding, and putting it on and taking it off. I think Im just gonna buy one next time.