Building Custom Exhaust

[Mitch41]

Hey guys. I have a first generation Evo with a stock small 16g turbo and stock exhaust and ported o2 housing
I'm working out the plans for a 3" exhaust from o2 housing and back.

I have some questions and I want to gather opinions on everything.
First off. The flange from the o2 housing is only 2.5". Does anyone know where to get a piece that goes from 2.5" to 3"?
I have been looking at the fabrication parts from RRE. I noticed that part of the flex pipes from there are made of aluminum. I was hoping to build everything of 304 stainless steel. Is it a good idea to have aluminum parts mixed in? Is there anywhere I can get a full stainless flex section.
Looking for opinions on 1 12" resonator or a 24" resonator or 2 12" resonators.
For a muffler I have been thinking I will run a Dynomax VT. I'm concerned about how loud my exhaust will be and I think this would work well for cruising and in the city.
I also am wondering if anyone has experience with cutting pipe like this with a band saw or cutoff wheel to make corners or slight angle changes. Or should I buy mandrel bends or a donut to make these work?

Thanks all.
Mitch

 

[dexterholland04]

We used a chop saw and a big belt sander to cut/prep the piping for my exhaust. Mandrel bends are best when fabricating an exhaust, they allow for the most flow. You can get the 2.5" to 3" section from the o2 housing from Extreme PSI.

 

[Mitch41]

Hey guys, I got an update here on my tubing. I ordered 20 feet of it through a local piping supplier. Got a great deal on it. 3" 304 Stainless, in milled finish.
I thought I had a source on bending the pipe. But it did not work out. So I'm currently working on finding a new source locally to do this for me.
I have both my turbos apart in order to be ported. New exhausts all around. And my turbine housing, o2 housing, and manifolds have been bead blasted at this point!

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

Also. Here's a view of another Evo. With my basic plan. Depending on if I can get my muffler on a similar angled exit!

You must be logged in to view this image or video.

 

[95eclipseguy]

Are You tig welding this together?

And just a note: Is the drive shaft in that pic kitty-whampus in front of the carrier bearing or is it just my eyes.

 

[Mitch41]

It totally is messed up! That's interesting.
My neighbor has told me he is able to weld my tubing. I showed it to him and he said he had the proper rods for it. He is quite an experience welder. I'm assuming he will just be using regular arc welding however.
Next weekend when I am home I am going to cut two small pieces and get him to practice his welds on those to make sure they are suitable.

Also. I ordered a 3" v-band yesterday.
So the pipe will go 2.5"-3" immediately off flange, bend down, v-band, flex, 24" resonator, then dynomax vt muffler.

 

[Mitch41]

So I have now made what I would consider a large amount of phone calls. There are no places in my province that can do mandrel bending. I seriously thought it would be more common!
I am waiting on quotes for a couple elbows from local sources. Will keep this thread up to date.

 

[supermario300hp]

you can buy a cheap bender from like harbor freight. I dont know if they have them out by you or not and you can just return it after your done. i think theyre like 150bucks.

 

[Sirnixalot]

^ definitely not mandrel bends.

I dunno who Yonaka is but its in Canada
https://www.rtmracing.com/xcart/product.php?productid=17278&cat=472&page=1

You could always pizza slice it?

 

[Mitch41]

My problem with pie cuts is it will take so many. And since I'm not the one doing the welding... I kinda feel bad if I had that many welds for him to do!
I've found lots of online pricing but hoping the local shops will come in cheaper.
Anyone have experience in getting things mandrel bent in Canada or the northern states?

 

[Mr PopUps]

You can get a kit minus the muffler for $225 from VRSExhaust.com, not sure what shipping would be to you, but their kits are great.

 

[Mitch41]

Ordered 6 90 elbows at somewhere around 25 bucks a piece to my door from a local shop. Will know the true price when it's here
Will keep this up to date.
3" V-band is ordered should be in my mail box today or tomorrow.
Haven't ordered flange, 2.5-3 reducer, hangers, flex, resonator, or muffler yet.
Not sure how the piping will lay out 100%. That's why I have not ordered the muffler yet. Not sure if I want centered inlet or side inlet.
Still lots to go!