i need some general exhaust measurements...

[DaveMush]

I'm not in front of my car atm... I havnt been able to get over there for a couple months now (its at my in-law's)

I'm trying to buy some stainless exhaust bends to fabricate an exhaust on a 1mz w/ manual manifolds w/o precats.

I know i'll be needing:
(2) 2.25" 90deg bends off the muffler to the tips. ~3" radius
(1) 2.5" 180deg u-bend from the muffler to the cat/resonator 4" radius

I think I'll need:
(2) 2" 180 deg u-bends to get around the crossmember ~3" radius
(1) 2"45deg or 90deg bend to the front manifold ~3" radius

Can anyone get rough radius measurements of the bends in their exhaust?
and or pics?


Also, where is the best place to get a good price on stainless pipe?? eBay is good pricing, but the shipping per piece is almost as much as the piping...

Best i've found is actually summitracing.com

[4v6]

Hmmm cant really help you with measurements as i did mine on the 3vz.

However, the photos i took of the manifold i fabricated for the celica might help you a little?
Theyre not identical to what youd need but it may help some.

[JimKing]

Delete

[JimKing]

The 1mz manifold outlets are very close to 1 7/8" OD. This is the diameter I used for my Y-pipe:

Y-pipe for 1MZ

The merge is scavenged from a 3mz Highlander Y-pipe. I got my stuff from Burns Stainless overstock/closeout section. Best quality, but still probably more expensive than ebay. My sub-par welding skills did not do it justice.

[DaveMush]

i'm not worried about the manifolds... I just need to build the rest of the exhaust.

Brad Bedell mentioned that he uses everything at a 1:1 ratio... if the pipe is 2" OD, its a 2" radius, ect.

[JimKing]

Well, you need to build a Y-pipe, right? The merge on the stock ones sucks. In the photo of my Y-pipe, the section (with O2 bung) that mates to the front manifold is cut from a stock Y-pipe. See how the 1 7/8" stainless tubing is almost a perfect match, diameter wise?

BTW, I don't recall seeing any 2" (or 1 7/8") bends available with as sharp as a 2" CLR (Center Line Radius). The U-bend on my Y-pipe is 2.5" CLR, and even that is now discontinued by Burns.

Burns U-bends 304SS

[DaveMush]

jim, do you have the photo's hosted someplace?

I'm considering having the runner from each manifold merge behind the crossmember. Depending on ground clearance and the ability to go over vs. under the crossmember.
I had to extend the length of the front manifold due to the flange interfering with the torque mount, the shift cables, and the clutch slave cyl. The rear manifold just comes down a bit lower almost flush with the height of the crossmember, making it almost as easy to go under as it would be to go over.
I was planning on using 2" OD from the manifolds and 2.5" OD after the merge. 2" OD seems to fit perfectly in the stock manifold flanges, if not a bit tight.

[DaveMush]

sorry i'm a retard...
i see the pics. I'm reading and posting at work.

what are the lengths/diameters on your flex sections?
do you have a pic of the rest of your exhaust?

[JimKing]

what are the lengths/diameters on your flex sections?
do you have a pic of the rest of your exhaust?

Third post down:
MR2 Owners Club Message Board™

The flex section back is a standard Fujisubo Legalis-R exhaust for the MR2 turbo. The 3" flex section is part of the Fujitsubo exhaust. It is actually only 2.5" ID, so the inner flange on the flex joint mated up pretty well with the 3mz Y-merge, which is about 2.6" OD. I had to cut and "reclock" the section of pipe between the flex and and the joint that is by the crossmember. I cut a cat into the midpipe after the pics were taken.

The smaller flex section is 2" x 4" (overall) length from some online place.

[DaveMush]

Jim, any idea what that u-bend in your y-pipe measures in diameter?
Again, I'm not near my car to know how much room i have there to make the corner.

I'm debating if its easier to bring the two pipes together under the engine like stock 1mz's, or behind the cross member.

[JimKing]

Originally Posted by DaveMush

Jim, any idea what that u-bend in your y-pipe measures in diameter?
Again, I'm not near my car to know how much room i have there to make the corner.

I'm debating if its easier to bring the two pipes together under the engine like stock 1mz's, or behind the cross member.

The U-bend I used is 1 7/8" OD, 2.5" CLR. I got it from Burn's closeout bin, and that size is discontinued now. Clearance between oil pan and tranny was tight with this. With a 3" CLR U-bend it would be tougher to fit together w/o cheating some of the joints.

[DaveMush]

I guess that means I'll be bringing them together behind the cross member then.

[DaveMush]

HA!!! I've found a place with 2"OD 2" CLR 180deg bends... should be able to keep it somewhat stock looking w/ a better merge and slightly larger diameter.

And they have 2" x 4"Long flex sections in both interlock, and braided centers.

Stainless Steel Elbows - 180 Degree U-Bend Mandrel Bent Tubing

[JimKing]

Nice find. Bookmarked.

[DaveMush]

I ordered $250 from columbia river mandrel bends, and $150 from verocious motorsports. should be more than enough to build the complete exhaust minus the manifolds and crossflow-muffler.
I'll let you know how quickly they each process/ship the order(s)

And I'll post the pipes when I'm finished with them.

[DaveMush]

Built this over the past few days. havnt had a chance to listen to it yet cuz the battery was dead when i went to start it last night...
Made out of 304 SS with stock flanges cut from an extra set of pre-cat manifolds that came with the engine...

Clearance is tight (1/2") to the underside of the engine, and 3/4" in all directions over the cross member.
Used 2" pipe from the stock flanges, to 2.5" after the collector, to 3" in/out from a tundra 5.7L resonator, to 2.5" into the camero crossflow magnaflow muffler, to dual 2.25" outlets... No tips yet, they are for later.

click to enlarge:

[JimKing]

Nice work. If you're using the stock manifolds, using some OEM flanges for your custom Y-pipe is the way to go. The tight radius U-bend is necessary if you want to build this style Y-pipe.

[DaveMush]

sound clips posted on youtube

You Tube

You Tube

[Oteck]

im going to get one of these to merge my exhaust, perfect for those tight spots
STAINLESS STEEL 2 in. DONUT - C76-564-SS at The Chassis Shop