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Exhaust manifold bypass.....something a little different maybe

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Old 02-12-2009, 07:32 AM
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Exhaust manifold bypass.....something a little different maybe

While I have the heads off the 3.0, I decided to take a look at the crossover and manifold situation which pretty much everyone agrees is not well designed from the factory. Instead of doing the y-pipe mod, I cut the flange off the crossover at the driver side manifold and extended it to the main exhaust about a foot below the manifold flange. I've included pictures....one with the mock-up I took to the muffler shop, one showing it in place on the engine and another with it in the vice . I've only gotten as far as to test fit everything, but it looks good. Thought I would share.

I have larger pictures, I reduced these as per the "post-your-picture" instruction page.

What do you guys think?
Attached Thumbnails Exhaust manifold bypass.....something a little different maybe-cimg1387.jpg   Exhaust manifold bypass.....something a little different maybe-cimg1397.jpg   Exhaust manifold bypass.....something a little different maybe-cimg1395.jpg  
Old 02-12-2009, 07:45 AM
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It certainly can't be any worse than the original design. It's fairly similar to what they've done for the 3.4 in later models, like mine for my swap:
Old 02-12-2009, 11:08 AM
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Don't understand why they didn't do that to start with.....
Old 02-12-2009, 11:27 AM
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For anyone doing this consider reinforcing the "Y" real good. A lot of us with custom crossovers for 3.4 swaps have had problems with cracking at the "Y".

More info: https://www.yotatech.com/forums/f160...42/index9.html

Here's mine before repairing the crack:



After repairing the crack:


Last edited by mt_goat; 02-12-2009 at 11:51 AM.
Old 02-12-2009, 11:37 AM
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Didn't Toyota use the EXACT SAME CROSSOVER PIPE on both the 3.0 AND the 3.4? No problems with the 3.4, are there?????

or am I an idiot?
Old 02-12-2009, 11:39 AM
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Originally Posted by krb90
While I have the heads off the 3.0, I decided to take a look at the crossover and manifold situation which pretty much everyone agrees is not well designed from the factory. Instead of doing the y-pipe mod, I cut the flange off the crossover at the driver side manifold and extended it to the main exhaust about a foot below the manifold flange. I've included pictures....one with the mock-up I took to the muffler shop, one showing it in place on the engine and another with it in the vice . I've only gotten as far as to test fit everything, but it looks good. Thought I would share.

I have larger pictures, I reduced these as per the "post-your-picture" instruction page.

What do you guys think?
I see a cracked crossover in your near future. Why didn't you clean up that rusty pipe before welding that "Y" into it? That's just welding basics. Maybe the pic is too small for me to see and you did.

Last edited by mt_goat; 02-12-2009 at 11:44 AM.
Old 02-12-2009, 11:40 AM
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Originally Posted by TNRabbit
Didn't Toyota use the EXACT SAME CROSSOVER PIPE on both the 3.0 AND the 3.4?
No...
Old 02-12-2009, 01:59 PM
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Originally Posted by mt_goat
I see a cracked crossover in your near future. Why didn't you clean up that rusty pipe before welding that "Y" into it? That's just welding basics. Maybe the pic is too small for me to see and you did.
Just where the weld is, cut and ground down, the rest can stay rusty...but your reinforcing suggestion is something to think about. I'm gonna have my friend take a look at that and see what we can do. Maybe a stiffener in the "V", kinda like what you would do to a steel beam. Thanks for the heads up on that.

I'd say if yours ever cracks, you got alot of other broke stuff too.....my compliments. Nothing wrong with a little overkill.
Old 02-12-2009, 04:53 PM
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Originally Posted by krb90

I'd say if yours ever cracks, you got alot of other broke stuff too.....my compliments. Nothing wrong with a little overkill.
Yeah I didn't want to ever take that off again.
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