Doc279

Anybody ever remove the exhaust cross-over and adapt a pipe to the passenger side and block off the port on the driver side cross-over port ?

Is this impossible or can it be done ? Any write-up's ?

hamstrungtaco

ur saying separate both exhaust pipes

Doc279

NO - I am thinking that the cross-over pipe from the passenger side exhaust
manifold crosses over and joins the driver side exhaust manifold - then the exhaust header pipe connects to another port on the driver side manifold.

What I am thinking is that the cross-over pipe could be removed and the port on the driver side manifold - where the cross-over pipe connects could be blocked off with a plate. The passenger side exhaust manifold could have a pipe adapted to it and the exhaust routed down the passenger side and then crosses over to join the header - just forward of the Cat.

It does not make sense for the passenger side manifold to dump 3 cylinders worth of exhaust into the driver side manifold and then all 6 cylinders exhaust have to go out a single pipe. I am just wondering if anyone has ever tried to do away with the cross-over on the engine this way. Am I thinking to hard ?

hockeytown9

Bump?

Eric

you mean like this?

DMG

I did it on my 88 V6. We called it Frankenpipe because I did it without a bender, just 2 leftover Y pipes off GM cars that I cut and turned until they fit. It is ugly but works. (ask Cebby, I think I showed it to him)

You could have a muffler shop do it but I wanted to try it myself

With this, AFM turned richer, egr disconnected, and timing advanced I spin 33s with 4.30 gears just fine, rarely have to downshift.

DMG

Doc279

EXACTLY !!!!!!! You da man !
Now figure out what we need to do this - I believe that if I could find
a spare cross-over pipe that I could make this work. I don't want to cut mine - just in case. I looked at the cross-over pipe when I got home,
it looks like if the heat shield was trimmed away that the pipe could be cut
and another pipe adapted to the cut. What I don't know is if the cross - over pipe joint will allow the joint to swivel down and seal on the passenger
side manifold. I would use the other piece of the cross-over pipe to make a seal for the driver side port by capping it off.

Based on all that I have read - this would allow the engine to breathe better and run better with more torque - just like a set of headers !

Somebody in an earlier thread mentioned "poor boy headers"
If I can do this without spending the $700 - $900 that everybody talks about when installing the header system - I don't care what it looks like as long as it don't leak and serves the purpose. The exhaust could be expanded to the 2.25" pipe all the way from the Cat to the exit point - free flowing even !

Anybody got a cross-over pipe off ? will it swivel ? I replaced my engine last July and I remember the new gaskets but I don't re-call if the triangle flange ( 3 bolts on the cross-over joint ) would move or not.

I see this as a cheap alternative to a question that I have heard since my first day here. Red neck inginuity at it's best.

kevin444

I feel there wont be enough turbelence if you were to make the gases expel across a long pipe like that. I feel make it optimal and decent by the under the tranny technique.

Eric

pleaes explain said tranny technique???


Doc279 - no the crossover pipe does not swivel... you need to cut the pipe at the flange and weld onto that

or are these flanges redilly availible?

kevin444

A shorter pipe is all im asking.

sportJr

I dont know much about motors, but I do heating and air calculations. One ot the things I do is lay out systems for buildings and try to get the max amount of air everywhere we can. The first drawing makes it look like port 5 would get back pressure from ports 2, 4 and 6. But on the proposed drawing it would flow freely from all ports. I see what kevin is saying on the long pipe, (or at least I think I see what he is trying to say) and it shouldnt matter since the air is being pushed from the source. If it was pulled, like on a snorkle lets say, the distance does matter because the engin has to work harder to pull the air from the friction in the length of pipe. That is why we start large and work smaller for velocity. What I am saying is that it, in air flow theory, would improve things a fricken bunch. If a guy sized the two pipes togather at the cat and went larger it would help more, kind of like the stupid little coffee can mufflers on the chevettes ya see around. goofy and annoying, but effective.
I do not know what this will do to the motor or the computer systems but ya may be on to something.

DMG, how caome ya didnt bring this up when everyone was whining about there 3.0 not having enough power??? This sounds like a feesable wat to fix some of that.

Lets here from some of the Mechanical experts on the board. I just do heating and air.

HondaTec521

also if you have an auto,there is lotsa stuff on the right side of the trans that has to be moved.

Doc279

I am now in the search for a cross-over pipe from a 3.0 that I can cut up
and experiment with. If the joint does not swivel - can it be mounted
where the cut would exit down or to the frame side. I am sure this would work with some effort.

My biggest problem would be getting the left driver side manifold port
sealed after cutting the cross-over pipe - If the existing flange could be cut
where it enters the manifold and the pipe sealed there - ( capped off )
then that sound solve that. The fire wall is close at that point on my runner - the trucks may have more room.

As far as the right hand manifold goes - the same principle could be used - using the same short section of the cross-over pipe - just need to figure out a way to point the pipe down or angled towards the frame to make the pipe joint. Could the flange on the existing elbow - have the welds ground off to allow the joint to swivel ? The length of the pipe crossing over at the transmission or aft of the transfer case would not make any difference as long as it joined the left pipe forward of the Cat - Dual exhaust was not my plans ! The engine will require back pressure to run properly - as long as this happens before the Cat - I don't forsee any problems.

I am going to do this soon - just need to have an extra cross - over pipe before attempting this. I do not want to cut mine apart and then have the runner down a few days because of an unforseen problem.

Somebody find me a pipe and I'll do the write up and results for the rest of you !!!!

Eric

have you ever removed the crossover pipe?

your best bet is to take it to an exhuast shop, tell them what to do, and let them remove the crossover pipe.


oh and have them agree on a price before they do the work.


It took me 6 hours to remove and replace the crossover pipe wen I changed the gaskets.


and i guess you didn't read my previous post, the crossover pipe is not on a swivel, they are welded to the flange, woud you like a picture, I have one sitting on the ground right now

Glenn

If you want to make the exhaust like the pic Eric posted, will that new crossover be anywhere near the fuel tank? Owning a truck, I am not sure where the fuel tanks are under the 4Runners. Something to think about .... It sounds like a great idea, though.

Eric

pretty sure it would be by the fuel tank, it goes the same route as the downey and NWOR pipes.

also my fuel tank in my BMW was under the seat... the exhust went right unerneath it.

I doubt there is any trouble with running a exhaust pipe next to a fuel tank, now if you have a clogged cat and your pipe is running at 1,500 degrees, then you should be worried

runnerboy97

ive got a new crossover pipe left over from when i rebuilt my 3.0L. ill sell it to you. PM if you want it.

ATP4984

Tag to see how this turns out.

ALSO, Eric, post that pic, some of us are huge noobs.

Doc279

The fuel tank on my 2nd generation runner is on the passenger side aft of the rear seat - the exhaust runs down the driver's side - no problems there.

I could take this to the muffler shop - but then I would be at their mercy after they cut my cross-over pipe. I would rather figure this out myself
that way I could document for the rest of you. I could get the pipe and weld it myself. a local muffler shop will make any pieces and bends that I want - spoke to the guy about it yesterday.

I had the cross-over pipe off last July when I had to change the engine while on vacation - 400 miles from home. I remember installing new gaskets for the cross-over but at the time I was not thinking about this - sorta had my hands full already

If I can get the cross-over pretty reasonable then this idea will take off as soon as I get it. I'll PM you in the morning regarding the pipe.

Does everybody see merit in this idea ? I think it is worth the effort !

ATP4984

See the merit? Absolutely, I'm waiting for the results already. I often wonder what the engineers who designed this engine were or weren't thinking. However, I'll give any Toyota engineer the credit they rightfully deserve. My 11 year old rig with over 183k on it runs great.