homemade HA downpipe...

[O SO LO]

Been working on my Christmas present to myself...
Not quite finished but its a start.
This is 2 1/2" though... Enough for what I need for now.

 

[Jerryl]

Mark,
That looks awesome!
What material?

Edit;
Is this a 2-piece unit?

 

[O SO LO]

I originally bought 2 u-bends from Jeg's and cut one up which is in the pipe-one left over-- then later bought a 90 and a couple of 45's from NAPA--easier to cut up. This is a two piece unit although for assembling the joint is tacked at the moment. It is made of aluminized pipe and mig welded together, would like to have ceramic coated like Poston headers. Need to look into that a little more.

I had the lower pipe in a straight line- laid on my weld bench and tack welded together but it hit in to many places, thus the dog leg before the cat flange-- like the original pipe. Upper pipe off turbo consists of three 45 deg. angles creating a slight dogleg for A/C unit clearance. I have a 1" gap above A-arm bushing.
If you look closely at top pic my original pipe rubbed on the bracket on A/C drier- the spot shown where stainless covering is frayed...

 

[Jerryl]

I originally bought 2 u-bends from Jeg's and cut one up which is in the pipe-one left over-- then later bought a 90 and a couple of 45's from NAPA--easier to cut up. This is a two piece unit although for assembling the joint is tacked at the moment. It is made of aluminized pipe and mig welded together, would like to have ceramic coated like Poston headers. Need to look into that a little more.

I had the lower pipe in a straight line- laid on my weld bench and tack welded together but it hit in to many places, thus the dog leg before the cat flange-- like the original pipe. Upper pipe off turbo consists of three 45 deg. angles creating a slight dogleg for A/C unit clearance. I have a 1" gap above A-arm bushing.
If you look closely at top pic my original pipe rubbed on the bracket on A/C drier- the spot shown where stainless covering is frayed...

Can you still get to he plugs?

 

[turbonut85]

Been working on my Christmas present to myself...
Not quite finished but its a start.
This is 2 1/2" though... Enough for what I need for now.

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DROOLING AND JEALOUS ^^^^^

 

[luisturbog]

Been working on my Christmas present to myself...
Not quite finished but its a start.
This is 2 1/2" though... Enough for what I need for now.

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That looks great!

When does it go into full production?

I wonder if you could do the same with 3"

I don't know why g body is taking so long on the one they said was coming soon!

 

[turbonut85]

Mark---I wish you lived closer so I could see it in person!!! You would have to get it jet coated before I look at it though, my drool would make it rust!!:biggrin: LOOKS GREAT!!

 

[BRAD_PADGETT]

Been working on my Christmas present to myself...
Not quite finished but its a start.
This is 2 1/2" though... Enough for what I need for now.

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View attachment 62594

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Mark- Nice job on the downpipe. You should see nice performance increase since the 2 inch turbo elbow is gone. Take- care. Brad

 

[O SO LO]

Yes, I can get to the plugs although it will be a bit tight-- that's why the top part will come off if all else fails! This is similiar to Mease design. I figured this is a definate improvement over the stock downpipe.

 

[Squid4life]

Wow, very nice work!

 

[T-Type85David]

VERY NICE see thats whats kinda like my idea,
a j bend,U bend, or and 45 etc we could make are own DP! "We don't need no... stinkin' badges!" NICE, i plan to do so, tho i will kept my elbow I KNOW i get it for saying so but I DIG THE ELBOW haha

 

[Jerryl]

Don't forget to add the O2 bung for your WB. :tongue:

 

[GNeric]

I kind of did the same thing back in '02 for my 85 GN. I wasn't able to get a flange so I had the stock elbow machined down to 1" thick and used the torch to weld the pipe to the cast iron flange I had left. Used 7014 rod and heated up the flange to make it penetrate. MIG welded the rest together. Mine was 3" all the way to cat flange and was a 2 piece unit that used a flat band clamp and was easy to get to spark plugs. Mine didn't look anywhere near as purdy as yours though. I should have cleaned mine up more and coated.

 

[novaderrik]

i'm gonna be doing mine hopefully in the next few months- i might go 3" just because it leaves more room to grow, and have been thinking that getting some of that oval tubing in there might make for a little bit more room to get at the plugs.

 

[O SO LO]

Don't forget to add the O2 bung for your WB. :tongue:

Good point Jerryl...it's easier to do it now than later

 

[Jerryl]

Good point Jerryl...it's easier to do it now than later

True.
Also, make a jig ......... for the next one! :wink:
It will be a LOT easier ...........

 

[O SO LO]

True.
Also, make a jig ......... for the next one! :wink:
It will be a LOT easier ...........

This one worked for me...:wink:

 

[Rottydogg84GN]

So how much would it cost me to get you to make me one for my 84.:biggrin:

 

[O SO LO]

Downpipe pics are posted in my webshots link under the Hardtop GN album...

 

[O SO LO]

I kind of did the same thing back in '02 for my 85 GN. I wasn't able to get a flange so I had the stock elbow machined down to 1" thick and used the torch to weld the pipe to the cast iron flange I had left. Used 7014 rod and heated up the flange to make it penetrate. MIG welded the rest together. Mine was 3" all the way to cat flange and was a 2 piece unit that used a flat band clamp and was easy to get to spark plugs. Mine didn't look anywhere near as purdy as yours though. I should have cleaned mine up more and coated.

GNeric--I like your pipe...