I have a 2.5" downpipe since my T3 garret has a 4 bolt 2.5" exhaust side. Just made sense to keep it 2.5". But my exhaust I have is a 3" Thermal R&D (actually just bought this) and I am wondering how to mate the 2 together. I haven't sized the Thermal Exhaust up under the car to see how much room/space I have to work with, but I am looking to see what my best option would be for connecting the two.

Should I go with a 2.5" or 3" flex pipe?
Am I stuck with a 2.5" pipe expanded to 3" to mate the two together?
Is there a way to use a vband to mate the two?

It's really tough finding some shots of this exhaust on an EF. I'm more of a visual learner and I'm having a tough time wrapping my head around exactly what the best way to go about this would be.

I know I should mount the exhaust and go from there, but I am hoping to order some more parts so I can get the exhaust installed sooner than later. This car is awful with a open downpipe and I hate it.

Thanks

EDIT: I personally know how to MIG weld and that's what I have at home. I have access to a TIG at work, but I've never used it. If I have to get some help with some welding, I can find someone to give me a hand.

 

i would redo the downpipe and weld a 2.5-3" transition right on the 4 bolt flange. If you want to keep the 2.5" downpipe, the only way to get to 3" is using a transition...maybe weld it to the end of the downpipe, then use a 3" vband to connect the downpipe to the exhaust

 

Basically answered my question right on the head.

I will probably just transition from the end of a 2.5" flex pipe to the 3" thermal exhaust. The downpipe fits well with my current manifold, I'm not sure a 3" downpipe with the adapter on the exhaust housing of the turbo would work. At least not how I feel I can fabricate it. I'm sure people have welded 3" vbands to their turbos and ran just fine. But I don't think that's up my alley.

Definitely appreciate it!

 

i get all my transitions i use from http://www.mandrel-bends.com/catalog...less-2681.html

 

A little on the high side when nappa sells em for $6. I know those are smoother, but for my use I think I can afford to go with a cheaper one for now.

 

Your paying for quality tho. this is stainless, those are probably galvanized steel and are used in a tube expander instead of a rolled cone.

 

I really don't want stainless since I don't have a TIG at home, which is where I'll be doing this. It's aluminized steel, which should last for 3-5 years. By then I hope to upgrade my manifold and need a new downpipe/adapter anyways.

Thanks though

 

Then what will work just fine. Good luck!

 

i used similar piece. It was $30 cuase it was longer allowing the transition to be even more gradual.

 

Down the line I would prefer to upgrade my manifold and get someone who is really good at welding to put a 3" Vband on my turbo so I can run a 3" downpipe to this exhaust. But until then, I'm not worried. I don't have enough power to sweat the little things. Main reason I bought this exhaust was due to my local shop sucking hard and the flange they welded on snapped and well.. long story short, my cat back isn't so hot around that area right now.

 

So I did it. Excuse the ugly welds. Function>Form?

 

I guess if it works it works. Good job man. Should hit it with a wire wheel to clean it up and make sure your welds are alright.

 

It was ugly, just to test it. I took it off, took it to work, grinded it down, hit the welds again. Cleaned them up, wire brushed the whole thing, high temp paint on everything but the stainless mesh.

The main point was to show case what I used to go from Thermal's 3" Turbo Exhaust to my 2" B16A header. This is what I plan on doing for my 2.5" downpipe too.