Doc279

Bump

Come on Monday mechanics

ATP4984

Bump.

dwh91102

your still gettin resistence from the stock exhaust manifold's, get some headers and be done with it

green91runner

i've also thought about doing this.. many positives (free-er flow, no risk of burning #6, more hp, etc) but, doesn't less back pressure = less torque? (i know there is a point where it will improve, but if you go past that point, it drops considerably)

Slowrunner

I looked under my hood and on the passenger side there is room to run pipe from the right side manifold almost straight down. If you could join the pipes under the tranny by the swat-bar I think it could work, but you would have to plug the cross-over pipe hole on the drivers side.

Doc279

I have a cross-over pipe coming but it is not here yet.
We shall see - I am going to do this - stay tuned !!!!

Eric

but this could solve the burnt #6 exhaust valve problem for much less money.

heades are a PITA to get (i've heard all the storys) and a bigger PITA to install.

this is quite a bit easier, if your under the truck you will see that there is actually quite a bit of room to run a pipe down the passenger side

Eric

INMHO you will have more backpressure than the headers people sell, and I've never heard of a loss of torque from the headers.

I only see positives with this idea, but if your really concerned with the loss of torque issue, then just run the same sized pipe once the two exhausts merge, this will create a small bottleneck in the exhaust flow, back up pressure, and thus preserve your torque

Eric

are you a pavement pounder? why would you want to run the exhuast under the tranny? that is a crushed pipe waiting to happen!

I see no problem with running the exhaust behind the transfer case. this whole "to close to the gas tank" thing is silly.... SO many cars have exhaust's that run next to, over or under exhust tanks, it's just a non issue.

heck I would be more worried about wrapping a 200degree copper pipe around a feul line to help create vapor lock, like some other guys on this board than run an exhaust pipe 4 inches away from my fuel tank

rockota

On my 4.3 swap, the crossover was behind the tcases. On my 4Runner w/ the 3.0 and Downey headers, the crossover is under the tranny. I prefer the latter, actually. Gives more room for a cat, keeps the exhaust farther away from the exhaust and fuel filter, etc. I don't see it at risk of being crushed - the driveshaft will hit long before anything gets to the exhaust tubing, at least on mine.

Eric

true forgot about the whole driveshaft part.

so the downey heades go below the tranny? I thought they went behind the transfer case... does NWOR ones go behind the transfer case?

89macrunner

if going through with this design why not just seperate the exhausts and put an H pipe in? of course that would be more expensive

ATP4984

Bump.

Doc279

I recieved the cross-over pipe that I ordered and have been studying
it for a day or two. The triangle mounting on the cross-over pipe for the passenger side exhaust manifold is a true triangle - so once the pipe is cut
and trimmed - it will rotate down by moving the triangle flange on the studs.

The driver side manifold is not a triangle - and will only mount in the original
position. I've taken a die grinder and released the heat shielding from the cross over pipe and cut the pipe where it meets the KNOT in the middle.
( I've taken pictures but left my camera at home today )

Tomorrow - I am going to get the section for the driver side manifold welded
shut. The pipe for the passenger side will have to be lengthened to drop down the hole between the frame and the transmission. Once I am satisfied that the plan does not have problems - I'll sawzall my cross-over pipe in order to remove it. I may be without my runner for a day or two unless I can find a weekend muffler shop.

More as I move through this - stay tuned !

mt_goat

I think the problem with that is the 3.0's one O2 sensor. Cars with duel exhaust have 2 or 4 O2 sensors. My BMW has 4, one before and after each cat. Maybe this problem could be over-come.

Eric

you must have a V8 in the bimmer, what model?

I think I'm going to just cut up the crossover and make pipes from the flange back and not worry about using any of the crossovers pipes.

however I"m going to have a friend/muffler shop do it, so If you are trying to save some pennies, I wish you the best

rivercat

i've got an extra set of maniflods and crossover if anyone needs a subject for some madscience.....

rivercat

i wish you could run true duels... get a jcw cheepy side pipe setup but there is no way around the o2 sensor... it has to read the flow from all six cylinders or the signal it produces can't be read by the ecm....

mt_goat

[QUOTE=Eric]you must have a V8 in the bimmer, what model?

QUOTE]

97 328i, in-line six cylinder (2.8L). Sweet engine, lots of power.

Eric

I forgot about the "dual exhuast" on OBDII M52 motors.

I had a 95 M3 for almost a year, such an incredible car, the E36 platform is phenominal