Not sure if this has already been done before, but i thought it would be really cool to try make a true 3" exhaust. Here is what it looks like.. About 98% done, just need to remove the cat and replace it with the flex section instead. Also, might have to re-do the charge pipe so it doesn't touch the dump tube. Any comments are all welcome.

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In the middle of the project had to go and pass emissions, not feeling like having to weld the CAT on there for the last emissions inspection, i just decided to stick it in there without welding. It worked, car passed emissions!

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Tried my best not to warp the vband so had to start and stop about 20 times

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Wow that's pretty awesome, good job. Now do mine =D

Wish I could weld like that

Pretty damn sweet, man! Ive been wanting to do one similar, but on the dump tube, Id like to do a 38mm Tial or the low profile Turbosmart wastegate and put it near where youve got the O2 sensor.

Great work and I like the o2 bung placement for sure. Very nice

I did my own too, but because I couldn't find one. Looks awesome, good job.

Thanks for the comments guys. Insane Performance, that is looking great man. I would like to try an exhaust manifold someday!

I love driving my car with the new exhaust on it, it really made a big difference in how loud the turbo is when off-boost. Has much more of that "the bus is coming" sound Have not tried wide open throttle yet, waiting till the fuel pump is upgraded and the cat is removed.

Here are a couple more picks with it installed, to show how tight the fitup is. Actually, had to cut down 3 washers to get it installed, and i might end up using an allen bolt where the stud normally goes.

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Do you plan on wrapping the dump pipe and the pipe under the pan?

nice looks good so far.

Looks like You walked the cup around the flange? You need more filler you have bad undercut and some gas pockets. The patern is agood start!but keep the puddle satisfied. Though I did My side exit abd a vband o2 housing i didnt look the grearest... When i first started welding.
I could do better now. now i weld like this.


Also if you aren't, you need to purge, it's tough with pie cuts cause your fitup is everything

I don't have anything to contribute to this thread except, "WOW!"

Very very cool exhaust.

That looks awesome!! I made one as well when I went Holset. Doesnt look near as good but it does the job!

Bryanwheat, no i don't think i'm going to wrap it. Plus, i can't put the wrap on the dump tube at this time because it won't fit.

UrbanSmoker, i had a feeling the welding guys are going to put my welds under the magnifier But, you are totally right, i did get a little undercut there. It actually looks worse in the picture than in real life. As for gas pockets, i really feel like it was something with the dump tube pipe itself. When i did the 3" pipe maybe had one picket on two different projects. But with this small dump tube it gave me like 3 spots of those even after putting a wire wheel to it, really dunno. The snainless welds look great, btw.

Crash89, that's not bad looking at all. I've always been more of the function over looks kind of guy anyways.

R1, it looks really good. It takes a lot of talent and patience to be able to get pie cuts correct. Most people would give up halfway through a project like this. I do like the shape of the dump tube, it looks "factory".
For the back purging, it's the correct way to do it but if you look at 85% of the exhausts on the maket including my 3.5" SS I made, they aren't purged. I never had an issue with it. Some people like to act as if it isn't purged then it's going to fall apart. Im no self proclaimed expert like some others, but based on my experience, If the option is there to back purge, then use it. Good luck and keep up the fabrication.

I would really consider at least wrapping the dump pipe. You are going to be transferring a ton of heat into the intercooler pipe, and the oil line is awful close to it also. I would also consider wrapping the downpipe under the oil pan because you will transfer heat into the oil pan, and likely heat the oil.

Looks great nice and clean as long as it works.

Everyones feedback is very appreciated. I would love to ceramic coat this whole thing, maybe later. For now, just going to keep an eye on temps and such. Would prefer not to have to wrap it.

As for patience, can't say i have too much of it. But, had to make up for it with inventing new words and pharases in a foreign language. So, my neighbours won't understand

I got around to finishing the rest of this project. Here is some more fab pron picks

Welded on a flex pipe, which was a pita because it was designed to be tightened with the pipe installed and not welded. In other words, it was like welding sheet metal.

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The full complete exhaust next to the old one with the evo3 o2 housing. Towards the end was running out of 3" tubing, so had to resort to using left over pie cuts.

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Can see light through the mid-section, hopefully not too much pressure drop

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Looks good and I love the idea but theres a down fall. Since its one piece at the turbo outlet, its going to be a pita to install and uninstall ontop of trying to tighten that back bolt. Other then that its cool and wish I had the patience, tools, and knowledge to do this.

Wow, such cool looking pie cut exhaust pieces! i love the look of them. I made one for my 1g that goes from a 3 to 3.5inch diameter at the turbo exit. It was a tight fit, so I decided to pie cut (also had a bunch of 3.5inch stainless straight tube i got for a very low price).

1990dsmkid said:

Looks good and I love the idea but theres a down fall. Since its one piece at the turbo outlet, its going to be a pita to install and uninstall ontop of trying to tighten that back bolt. Other then that its cool and wish I had the patience, tools, and knowledge to do this.

Click to expand...

I had this issue on my Hx35 with my downpipe. It kept coming loose as well so I ended up cutting it right after the oil pan and putting in a Vband. Along with putting a stud in the exhaust housing in place of the bolt. It was a pain trying to get a bolt started in such a small area. Its still a pain but a little less now!

Yea its a nice cool idea but i think it would be easier to make a standard bolt on o2 housing that has a v band clamp for downpipe. This might not be possible or extremely hard to do im not sure. Im not a fabricator or a welder so not sure if its possible or not but would be sweet and feel there would be a good market if they could be made and produced.

This is awesome, i love that people are posting pictures of their own fab work in here, even if they are for different setups. I'm already starting to get some ideas for future projects just from the other peoples pictures in this thread. Encourage others to post up their work, it would be nice to have all these different setups in one thread. IMO

As for the ease of the install and uninstall, i knew that it probably won't come out to be the easiest thing to install before i even started this project. Than again, most people don't put larger exhausts/turbo's on their cars for the ease of the install.

With that said, as tight of a fit it really is, it's not harder to install than my old exhaust with a weirdly angled evoIII O2 housing. That was a pita in itself. It could even be argued, that this new exhaust is even a bit easier for me to install and remove.

As far as, the back nut with the stud. There are three options for installing it properly. Removing the radiator (not ideal), cutting or finding a short 14mm open end wrench, or installing an allen bolt instead.

I like the idea of an allen head bolt. That never crossed my mind as an option to look into. Now I know what I can do for a little bit tonight.[DOUBLEPOST=1412894386][/DOUBLEPOST]Did a quick search and for one. Its cheap and a high grade and should work without a problem.https://www.boltdepot.com/Product-Details.aspx?product=15751
https://www.boltdepot.com/Product-Details.aspx?product=15751

For the guys that are making these pie cuts, what are you using to cut? Angle grinder? Bandsaw? Miter?

Crimsondragon,
Personally I am using a band-saw to make the pie cuts.

thats a nice piece. ive always liked the cut angles look. takes forever tho. def wrap that pipe