AWD DIY 3" exhaust

[ssicb]

so i don't want to shell out $500+ for an exhaust and, looking at the exhaust path of the 2G AWD, it looks pretty straight with only a couple bends needed. my idea is to piece together a 3" exhaust and take it to some a friends race outfit and have them weld it all up and such.

i hope someone with a great deal of 2G AWD experience reads this and replies because i don't want a bunch of people guessing at how difficult this project will be, i've already get that covered.

here we go:
1. [downpipe] starting with a 2.5" O2 housing, i need a 2.5" 90 degree bend to get under the oil pan and then flare to 3" and add in about a foot of flex pipe for good measure.
2. [cat area] i am going to go cat-less but install a resonator [mid-muffler] about where the cat would be. can i just use straight pipe for this part? it looks like there is room for it under the car so that is the plan.
3. [cat-back area] at this point i think i will need a 3" 45 degree bend to get the pipe to angle over to where the exhaust cutout is in the bumper. and i would be installing another muffler here.

parts needed:
1x 2.5" 90 degree bend [radius size?]
1x 3" 45 degree bend
1x 2.5" to 3" flare
1' 3" flex pipe
15' 3" straight pipe
2x high flow 3" in/out mufflers
1x 2.5" flange to O2
4x 3" flange [not sure on how many pieces it will have to be. 1, 2, or 3]
3' bar stock for hangers
1x buddy with a welder, time, and patience

any insight would be great.

 

[bryanwheat]

You have to weld it together on the car if you want it to fit decent, but it seems like you are on the right track. I usually spend around 120-150 with pipe, flex section, flanges and adapter for the flange. You will also need 2 45 degree bends at the rear if you want it tucked up in there and not dragging. Why are you using 2 mufflers?

 

[crash89]

I made my own out of my Megan GST down pipe, the muffler from my old cat back and 3" stainless steel.. I had to cut the "s" bend from the dp and weld a straight pipe, cut my flange off and re-weld where it would make the dp sit where I wanted it then flanged the end again. Then a huge straight piece with my muffler welded on.. Lots of cutting and grinding to get the fit I wanted.. Once I had it all welded up I had to bold the "catback" up and hold the rear part up with a jack and mark places for the hangers.. That wasnt easy to do by myself.. Then I cut off the old hangers and heated,bent and welded into place.. Im pretty satisfied since it was my first time trying something like it. Heres some pics for you.

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[Colt4G63 also]

Here's mine, but it's an AWD Colt, so I had to build my own. If I could just buy mass produced parts, I probably would have to save money and time.

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I don't really see how buying a bunch of pipe and paying someone to make a custom one off system out of it would be cheaper than buying one premade.

 

[ssicb]

@bryanwheat the two mufflers idea is just to make the car sound close to stock and not ricey. I had a stock gst and loved how it sounded so without a cat I need something to make the car growl and not fart. Ya dig? And thx for the info on needing two 45 degree bends.

 

[Boostinsideways]

Thats what resonators are for....

And Colt4g63 Also, I had my downpipe fabbed for > 40$ including materials.... I think my exhaust guy charged me 5$ to do the welds. Of course I have do all my shit when he is on break or off work and pay him under the table. If you know the right people its a hell of a lot cheaper to get it made yourself.

You could make an entire turbo back with a nice muffler, resonator, and flex section for an AWD for > 200$. FWD Might a bit more due to complex bends.

 

[ssicb]

@boostinsideways Resonator ... Muffler ... Same thing. Sub 200 is what i am lookin for! With good flow and great sound!

 

[Boostinsideways]

Sub 200 is doable, probably not with 2 mufflers. Good mufflers are usually around 80-100$. It just depends on the material you use for pipe and how cheaply you can get welding done. Your far enough north I wouldn't recommend anything other than stainless.

 

[Colt4G63 also]

Yeah it can be cheaper, especially if you know the welder and can share the workload, but once you start getting into stainless and multiple mufflers the price can shoot up pretty quickly.

 

[ssicb]

No faith?

 

[Boostinsideways]

Your going to spend at least 100-150$ in pipe and weldels if you go stainless. Add in 20$ for flanges, and 5$ for a wbo2 bung, and 80$ for a decent muffler, and then 25 or so for a flex piece....

 

[bryanwheat]

That's why i don't mess with stainless for exhaust piping. Aluminized steel will last longer than most people own their car and is dirt cheap.

 

[ssicb]

Boostinsideways assumed stainless. I never said stainless. I have a question about this two 45 bends bryanwheat said I would need to make it fit right. Wouldn't one 45 degree bend do fine but the exhaust would just angle up and out a little?

 

[fallenauthority]

That's why i don't mess with stainless for exhaust piping. Aluminized steel will last longer than most people own their car and is dirt cheap.

I would have to disagree, I have seen many aluminized steel exhausts rust apart within 3-4 years

 

[Bricktop]

I don't have any pics But, I have made 2 3in exhausts for my cars. I used some $20 Summit glasspacks and neither sounded like a fartcan. I used one muffler where the stock cat goes and the other in the stock location. It has a mean "growl" and turbine whine is loud.

 

[bryanwheat]

I would have to disagree, I have seen many aluminized steel exhausts rust apart within 3-4 years

You might be talking about normal mild steel. Aliminized won't even have surface rust on it in 3-4 years.

 

[ssicb]

what do you guys think about a SS downpipe and then be straight up aluminum for the catback? just lookin for insight on this.

 

[Funfettie]

Aluminum is good, much lighter, but its going to oxidize faster

 

[ssicb]

i think i am going to go with a magnaflow resonator, cutout post resonator, and a magnaflow muffler. all steel and high temp ceramic painted to keep it from rusting instantly. i know it wont last forever though. i plan to move to a different turbo setup down the road anyway.

 

[DsMWookie]

I m not understanding why you want to build a mild steel or Aluminized steel exhaust when you can order a ebay special that has good reviews, it is stainless, and requires no fab work. Aluminized steel will show less rust than mild steel, but after some time it will begin to rust all the same and it does not weld nearly as good.

If you want to build a quality 3 inch exhaust because you want some added features like V bands and higher quality metals that makes sense. Otherwise you are just creating more work for no reason.

Ebay Special Right Here!

 

[TJCTalon]

Im running an ebay special exhaust right now and its not bad. Its not perfect buts its fine for how much it was.

I contemplate selling it and having a exhaust shop fab one up for me. Probably will this winter.

I suggest doing it custom. in the end it will be how you want it.

 

[simple jake]

If you're looking for some aluminum elbows or any mandrel bent elbows, check out Global Technology and Engineering They have great prices and they ship pretty quickly. I did my custom exhaust with their mandrel bent elbows and I love how it came out.

 

[ssicb]

@dsmwookie that would be an option if i had a 1G GSX but i dont. and 2G GSX is limited on ebay. i checked it out. plus, some people like to do work on their weekend racer. not to mention it will save a metric s**t load of money to do it myself.

@simple jake, thanks for the link man! company looks legit.

@crash89 do you think you used more than 12ft of straight pipe?

 

[ssicb]

can anyone tell me about how much straight pipe i will need?