Just wanted to share my 3in into 4in y-pipe that i made for my 6.0L swap. When i bought my hawks LS swap headers i got them with the 2.5in collectors and made a 2.5in into 3in y pipe. Well i got bored and decided to cut the collector off where it necked down to the 2.5in and tig welded on a 3in collector. Then i ran two 3in pipes into a single 4in with a 4 inch cutout. After the cutout i necked it back down to 3in. to go over the axle.

First the old y-pipe:




I made my own cross member out of some 1/4 plate and angle iron.


Passenger side of the cross member (I cut off the piece that sticks up once i was done).


Driver side of the cross member.

 

The new y-pipe has a lot more ground clearance than my old one, mostly because i didn't tuck the old one up very well when i made it.

Now the new Y-pipe:


There is just a small difference in size



I took my time building the y-pipe and smoothed it off inside for the best flow.


I added a nice little mount right in front of the cutout. It makes it really easy to remove the y-pipe because it holds it up while i take the clamps off.

Y-pipe installed


4 inch cutout located under the rear passenger seat hump.


Ill have to post up a video of how it sounds once i get my fuel injection swap finished.

 

Nice! I need to redo mine but im using 3 1/2 where us using 4'

 

Yeah 3.5 should be plenty big, its was definitely worth redoing mine. The final product was way nicer than the first one i built.

The exhaust part of this thread is what convinced me to go 4 in.
http://www.ls1tech.com/forums/genera...heads-cam.html

IMO mine will even flow better than the one in this thread because the y-pipe doesnt neck down like his does and it has fewer bends.

 

Do you have any pictures of the car on the ground, I about to buy those same headers. I have a 700r4 that i am using as well in my swap and it's built for the 9's so should be good with the 700r4.

 

I dont have any pictures of it on the ground but i will take some this weekend when im home from school. With this y-pipe i have only drug it once, thats because i was driving on a country road and i tried to straddle a loose clump of asphalt.

Overall i am pretty impressed with the headers besides having to dent the floor in to clear the o2 sensors. Just make sure you build your own y-pipe because there are plenty of horror stories on here about the hawks y-pipe.

 

Ya I already have a guy that builds really nice exhaust systems, I was either going to notch the frame or notch the crossmember. Not to worried about notching it though. my frame is already a little tweaked anyways.

 

I didnt have to dent or notch anything with my SW Headers. All Fit perfect. Since SW was 5 miles down the street I dropped off my car and had them make me up a Y pipe so I know it would fit right ! lol Also had them use a resonator after the Y to avoid drone since I dont have cats.

 

i was referring to the y pipe for clearances, not the headers

 

Well thats convenient.

My car has never had any droning unless the cutout is open

What are you running for a muffler? I have a flowmaster 3in catback system.

 

Yeah the only thing i did before i made the first y-pipe was make that double hump trans cross member. If you dont make a cross member you pipes will probably hang really low.

 

Here are some pics of the clearance of both the headers and the y-pipe. My car has 3/4 of a coil cut off the front springs and stock rear springs.



Shows the clearance at the header.


Shows the clearance of the y-pipe. The lowest point is by the can.

 

I'm running a stock edelbrock exhaust that I installed back in 99. It was my first ever mod from bone stock. Its kinda rusty now but I want to see how far it takes me!

 

Haha yeah nothing wrong with that.

 

You should flip those clamps so the bolts are not the lowest point. My Vbands always scrap first at the collector.

 

Yeah i have been meaning to do that. The drivers side clamp cant turn much more up because the shifter linkage is right above that one.

 

Nice work