I'm gonna install a performance exhaust system on my 3.0 for my baseline dyno before I install the rebuild with the new heads, cam, intake etc. I'm gonna build a y pipe off of the stock manifolds to a 2.25 to a resonator to the muffler and then 2.5 out. My goal is to get the best performance and test the value of headers which I'll do after I have all the other mods done.

So here's my questions.

I could have a complete system made but I think it may be cheeper if I get a piece that comes off of the manifold to the CAT already made because it will contain the O2 bung and then plumb another piece from the other side to creat the Y pipe. Does anyone know of a company that sells that piece in 2.25"?

Also, I've been wondering which hole to block off on the driver's side manifold. If I block off the one the downpipe comes off of the I'll have both parts of the y hook up to the same spot on each manifold. Would this be at all helpful by creating balance from both sides?

Finally, if I build a completely new y pipe what would a good size for the pipe be?

 

We find on the cars that balance is about the least important thing as simply fixing our crappy y-pipe. Anything is better than stock, don't worry about flow balancing.
Don't wind up with something that's funky. it doesn't work!



For cars, we normally do 2, or 2.25" Y-pipes, post merg of 2.5" all the way back. My y-pipe is 2" EMT Conduit from Lowes into 2.5" post rails. I've still got a whole 12' of 2.5" post railing in the driveway LoL!

Pre-clean-up






I'm not entirely sure about what u mean on the headers. If you're talking about blocking where the crossover pipe goes into the manifold... Yes, do that LoL!



Buy ya, 2.25" pipes pre-merge & 2.5" post merge is exactly what ya wanna do!

 

As far as headers go I'll install those after the heads, intake and I try weasy's cams. Here is my order of events for the motor.

-Clean up exhaust (what we're talking about here) Do a baseline dyno run
-Bebuild w/Heads (OS SS valves, P&P) Do a dyno run
-Install the cams do a dyno run and rate daily driveablity
-Install custom plenum (P&P runners, bored intake tube, and custom air chamber) and bored TB. another Dyno run.
-Performance ignition (likely jacobs)
-Headers (depending on how things are working out)
-Finally either flashing the ECU or SMT tuning (I'm not sure what I'm gonna do here yet but we'll see when we get there, may need larger injectors).

I think 210HP is attainable the thing is knowing what all this will do. Step one though is the exhaust.

 

A simpler alternative for the driver's side exhaust manifold is to replace it with an extra passenger's side manifold. Just block off the emission ports, flip it updide down and it'll bolt right on. It's already designed to flow from the front cylinder straight back, so it might flow just a hair better than the driver's side one. I'm hoping to do this mod also this spring. I figured swap the manifold, cut the flanges/pipe bends off of the crossover pipe, find a Y-pipe in a junkyard from a v6 or v8, and fit/fab together into the o2 sensor pipe. I'm interested to see if this frees up some power. Wouldn't it be great if someone could market this kind of a setup as a "crossover elimination" kit? Hope this helps, and good luck!

 

Don't you mean the other way around? The manifold that flows the most would be the one that feeds the downpipe. Not to mention that the maniflod from that side would point the wrong way. Unless I'm misunderstanding you that is.

 

You're probably right about the manifold with the downpipe flowing better, and there's nothing wrong with using it. For myself, I'm thinking in the long run if I decide to get real headers, how hard is it going to be to remove that manifold with that last stud underneath buried in there, especially with the head/engine still in the truck? It was hard enough with the head removed! So its a convenience factor deciding to use a pass. manifold. The install will look cleaner with 2 passenger manifolds, hopefully be easier to remove (and transfer to my dad's truck) later, and I have access to a junkyard that specializes in toyota trucks. As far as the manifold not fitting, I put both of my manifolds against each other last night, and I turned the pass. manifold around to face forward, and the holes still lined up. You're keeping the manifold outlet pointed at the firewall, just rolling it over 180 degrees and bolting it on the other side. Well, I hope that answers your ?'s. I appreciate all the work you're doing to give us 3.0 guys some help!

 

Hmm sounds interesting. When are you going to get started on this?

 

Ummmm Hijack.
What is the part number for your 3vz-e ignition coil?

suprathepeg sounds pretty realistic power for the mods planned. The extra RPM that you'll be able to breath on the cams & the higher flow on the top 1/3 of your powerband via the head & valve work is going to really help peak horsepower & horsepower in general on the top 1/2 of the powerband.

 

Igniter assy - 89621-30010

Thats whats posted on 4x4wire.com Hope that helps. Why do you need the part number?

 

Don't know, but it'll be after I get my engine back in/together. Right now I have no job or $$ to keep going. I'll be darned if I'll ever put the stock, craptastically restrictive exhaust back on it! That's part of why my engine failed in the first place. I was hoping someone else would've done this by now, 'cause I'm so curious what the results will be.

 

I eleminated the cross-over pipe on my 3.0 last year and
it ran like crap - I posted the pictures and stuff on the board.

I reasoned that the cross-over pipe created back pressure that the engine needed. Not trying to stop you but it did not work for me.

I still have the pieces laying in my garage - made a cap off plate for the driver side manifold and custom bent the pipe and cross-over to join in front of the 02 sensor - I hated the sound and the power went down on my
newly installed engine - I changed it all back to stock form.

 

Well I was gonna say, if it's the same part as the 3vz-fe's use, you probably wouldn't need a better ignition. Like everything else, it's not the same part.


There's an easy way to increase the spark & dwell tho - but you'll want a dwell meter to measure so you don't go 2 far & melt the coil down.

 

How do you do that?

 

PM me. LoL!

 

PM sent.

 

Toysrme I sent you a PM but you haven't responded, whats up?

 

Oh and I was looking at your pics a little closer. Why did you use the factory flexpipe and why the big loop?

 

I coulda swore I wrote a reply & sent it. PM me again.

That first one isn't mine. It's a custom one on a Camry that didn't performance well. I didn't explain enough I guess. What I meant was don't do crazy piping like this guy in an attempt to get equal length. It's just not that important.

Me personally (I never took finished pics of mine). I used the stock flex because mine was in great shape, it fit & I had it.
IDK about a custom truck y-pipe, but on the cars, it takes bending & wiggling to simply get the pipes to the manifold & hook them up. Flex-pipe must be installed, or they simply won't clear in the first place without *extremely* careful pipe routing.

 

PM sent.