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3400 rear manifold with a 3100 downpipe? how?

Posted: Fri Jan 27, 2012 11:27 am
by Slinky
Ok so i put my 3400 rear mani on and it obviously dosent line up with the 3100 downpipe.

Has anyone done this?
how did u get it to work?

Re: 3400 rear manifold with a 3100 downpipe? how?

Posted: Fri Jan 27, 2012 12:04 pm
by 3X00-Modified
um, build a new down pipe...

My first revision sucked ass...

The second one was much better.

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This is standard 3400swap guide info too, I do not know why your even asking this question.

Re: 3400 rear manifold with a 3100 downpipe? how?

Posted: Fri Jan 27, 2012 12:19 pm
by Slinky
I think im just going to weld a SS Braided flex coupler at the top near the flange, it will let the flange bend into place and absorb exhaust vibrations too..

Any thoughts on that?

Re: 3400 rear manifold with a 3100 downpipe? how?

Posted: Fri Jan 27, 2012 12:20 pm
by 3X00-Modified
I tried to explain it and show what a 3400 dp flange has to look like but I guess you just don't understand.

Go back and re-read the 3400swap guide and then maybe you'll see the flange is no where near the same as a 3100 one.

Re: 3400 rear manifold with a 3100 downpipe? how?

Posted: Fri Jan 27, 2012 12:25 pm
by Slinky
And what i neglected to mention is that i already welded a piece of pipe on the rear 3400 mani so it would hold the 3100 doughnut and be the same as the 3100 rear mani, the only problem now is the angle..

Re: 3400 rear manifold with a 3100 downpipe? how?

Posted: Fri Jan 27, 2012 12:31 pm
by Slinky
so now any thoughts on that?

Re: 3400 rear manifold with a 3100 downpipe? how?

Posted: Fri Jan 27, 2012 12:58 pm
by 3X00-Modified
3X00-Modified wrote:um, build a new down pipe...

This is standard 3400swap guide info too, I do not know why your even asking this question.

Re: 3400 rear manifold with a 3100 downpipe? how?

Posted: Fri Jan 27, 2012 1:07 pm
by Slinky
ok ill take your advice and install the flex coupler

Re: 3400 rear manifold with a 3100 downpipe? how?

Posted: Fri Jan 27, 2012 1:43 pm
by 3X00-Modified
Yeah because that was my advice...

Re: 3400 rear manifold with a 3100 downpipe? how?

Posted: Fri Jan 27, 2012 2:24 pm
by Alpinestar10
Just get the flange cad drawings jon posted on 60degreev6.com have someone cut it and buy a bend and go to town, Yes install a flex coupler while your at it but why put a new flex couiple on a old system just spend the extra 25 for a mandrel bend and yard flange if you cant get one cut and youll be good.

Re: 3400 rear manifold with a 3100 downpipe? how?

Posted: Fri Jan 27, 2012 4:07 pm
by woody90gtz
The manifold is so close to the rack with an auto that with a pipe on it you might be sunk. I'd grab another manifold and make a pipe to bolt to it like Jon and I did. That 3100 donut is pretty small anyway, and the 3400 manifold is just about right for 2.5" pipe in original form.

I have a spare manifold, but already sold my custom DP to Shane.

Re: 3400 rear manifold with a 3100 downpipe? how?

Posted: Sun Jan 29, 2012 9:09 am
by MY91GT(Z)
I still have it sitting on shelf in my garage

Re: 3400 rear manifold with a 3100 downpipe? how?

Posted: Mon Jan 30, 2012 10:44 am
by woody90gtz
Glad to see you're making good use of it. haha

Re: 3400 rear manifold with a 3100 downpipe? how?

Posted: Wed Feb 08, 2012 8:17 pm
by wicked-irocz
Where do you live slinky? I could just make you one thats right.

Re: 3400 rear manifold with a 3100 downpipe? how?

Posted: Thu Feb 09, 2012 6:53 am
by MY91GT(Z)
he is from somewhere in pa