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Y-pipe - Why Stock Sucks

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Stock down pipes are 1 3/4" ID. The merge is only 2 1/4" ID. The flat section is 2 1/4" wide, but only 1 1/2" tall!!! You can see Toyota puts a fluted plate to help redirect the backwards flowing rear head the correct direction. That defiantely doesn't help at all!


The Y-pipe is the only part of the intake / exhaust that really restricts the power much at all. (Not including the cat convertor<s>)





You can see even in the bends 2" mandrel bent pipe dwarfs the stock 1 3/4". So does 2 1/2" ID exhaust pipe vs the 1 1/2" by 2 1/4" pipe after the merge.

Anyways... Was going to build me a new one for the turbo and decided to post pics of the crap-tastic stock pipe. I'll update it when I get a new one built.

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I slowly started working around 11:20am.

Put everything up and had this by 4pm.



Got a hair cut, got home... Was bored to tears, so I drug the welder back outside.


Did that in about 15 min. I'll have some nice 1-1 time to spend with the grinder tomorrow LoL! I need to pickup another stick of 2 1/2" pipe too.

It'll be done tomorrow, so I'll be happy.

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I agree as it is well know the Y pipe is drastically inefficent.

My query to your design is that it moves the axis points further down the exhaust piping which ends it under the body.

When the engine rocks forward it will cause 2 axis points which the exhaust will not be able to flex to be compliant to the new forms and angles.

As crappy as the OEM pipe is it is designed with purpose.

Some of the fabed ones i have seen take the original route but just have consistant lines to the oem with a open pipe without the restrictions.

The reason i ask i i was goign to attempt making one a few years ago , but it seemed impossible to make a nice one like the maxima guys who have the room for the needed changes.

So where are the turbo's going, under the car?

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There have been pleanty of 3vz and 1mz custom y-pipes made. Bumping isn't normally a problem if you test fit.

Before i put the Y and flex pipe on, I'll bolt the seperate pipes to the engine and tack weld it together

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Ya you nailed it. It's going to merge around the firewall. Just before the cat. And yes, the turbo is now going where the cat sits. No, I don't really expect oil flow problems, but we'll find out when it's up and running. (To answer the question right now) If it does F it. I'll spin the pipes around, re-merge them and do a normal install... After finding a way to route the up/down pipes around the huge A/T housing.

I didn't really get a chance to work today or yesterday, nor will I tomorrow. I'm unexpectedly spending most of my week on a Bobcat doing some work so... I hope I can get the pipe done sometime over the weekend, if not early next week, and get everything else finished by the end of next week.

Anyawys... I've gotten very little done over the last two days. I've been in a huge hurry too, so next to no welds have been ground down.


You can see in these two I'm working on the curve. It's almost there! One more angle cut and that'll be th horizontal plane!

And I've found out I need a new oil return flange... That sucks. eBay to the rescue!!! Hahahaha. hah. Not really much to say... It's time for there to be a lot of ES/Camry v6 turbo's.

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nice you almost make me feel like picking up the ES torch again .

I see why most turbos replace the battery to the trunk and put the turbo in its old spot.

Your turbo after the y-collector and flex pipe extenstions is almost going to be under your armrest by the resonator or are you not using flex pipes?

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Yes I'm going to use the flex-pipe. It'll sit in the former cat convertor location. There is a huge cavern where it sits... You could fit a LARGE turbo there and would probably never scrape it if you avoid coilovers, coilover sleeves, and stupid stuff like plowing speed bumps. 80_1_b.jpg36_1_b.jpg

The location is heat shielded for the correct amount of temperature simply because of the cat sitting there. (It's white fiberglass insulation, like what is in th stock y-pipe, and a piece of sheet metal tacked over it)

I see why most turbos replace the battery to the trunk and put the turbo in its old spot.

If you apply some logical thinking, you can see why this is bad for our type of application (a V engine, single turbo). You have to route the exhaust piping back up into the bay. Adding a lot of pipe, it's in a very hot location (but not as bad as sitting on the manifolds) There is limited space, and a lot of things in the engine bay are not tolerable to the 1000*F + a turbo can hit under sustained boost.

It's such a pain in the butt to merge your pipes together under the car, then route the pipe forward into the engine bay, then the return goes back down...

It's next to impossible to do it on our A/T's. The transmission case is HUGE. You can't fit 2 1/2" or large pipe by it!!! That only leaves extremely complicated piping setups like Tony Lueng did. (He's the man)

There is one reason why people "in the know" still install them there. The oil return. There is no pressure in the oil return. It's all about the gravity. If there is any restriction in the oil return (kink, small hose, blocking, up-hill...) oil backs up into the line. The only place for the incoming oil to go is right out of the seals.

There are a few "laws" about how the oil return can work. Widely accepted is what Corky Bell put in his book.

1) It ONLY flows downhill.

This is valid (He's the turbo god) but not 100% true. There ARE small up-hill flowing turbo installs floating around with no problems.

2) It can flow horizontally

There are plenty of junkyard turbo's that don't blow seals, while having fairly horizontal flows.

3) It can flow uphill, but no higher than the oil inlet

Think sink drain trap. A couple of isntalls like this on purpose with no problem.

Both 2 and 3 are avoided like the plauge, so you can't find any documented examples saying it simply won't work. What's different here, is that it'll have to flow a few feet (Probably 3') to the oil pan horizontally, and at a very small uphill grade!

It may, or may not work. Do I care? Sure, but it's not vital. Why? If it won't return correctly & I can't correct it, F it. I'll just install a scavenge pump. It'll STILL be a cheaper, easier install than piping into the engine bay.

I like being different anyway. 220-240bhp-ish isn't enough on a car this size.

SK go buy a half descent $150 wire feed welder off ebay, with one of the pimp $40 electric helmets. You don't need anything complicated. You don't really need any experiance. The welders suck... But you're not building a tube chassie, your putting exhaust pipe together. Those cheap little things do just fine at that.

You should. You got jumped a looong time ago. :P

1) n2o is cheap, just add a little fuel on top of a wet shot. A $2.50 cold start injector shoved in the rubber pipe after your maf, and triggered on the same 12v signal the n2o solenoid oughta add that lean-out safety barrier most people would be comfortable with.

2) You can machine the TRD turbo to fit the earlier 1mz-fe intake. (And the 3vz-fe intake, tho no one has done it. The intake manifolds will bolt to each other)

3) Turbo's can be done cheaply if you're up to it.

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