Outer Limits 4x4 Board

its time to upgrade my rusty old standard exhaust on the 80series.

I am looking at upgrading the turbo and adding an intercooler in the near future, with this in mind, the first thing I need to do is replace the exhaust coz its rusting to bits.

I am thinking of running a 4" dump pipe for 1metre from turbo, to help turbo spool up quicker.
then 3" mandrel bent system without mufflers to the rear.
I think I will probably run the exhaust inside the chassis rail from engine back, there looks like there is enough room, though exhaust would be fairly close to transfer.

Anyone done their exhaust like this?

Would you keep the cast "elbow" after the turbo flange or go with dump pipe straight onto turbo flange?

Would you fit a braided flex joint? Where?

Anyone see any probs with this setup?

Also can anyone recommend a good zorst shop in Sydney, preferably southern areas. Quality work more important than going for tight arze prices. will travel to get a good job done

You wont get 4" pipe past your firewall or transfer case without serious body lift. Also got wiring on that side and if you are not a part time t/case then forget it.

If you want the go and are prepared to pay - get a custom exhaust manifold setup and 3" all the way through. You gain spool up and wont burn your feet with 500 degrees under you!

I'm aiming to have a 3" setup all the way on the inside and I have 2" body lift to give clearance.

Good luck and don't forget your pyro!

You can go with 3" pipe out the frame and end it straight just ahead of the rear wheel ..

You can go with 3" pipe out the frame and end it straight just ahead of the rear wheel .. avoiding bends

I run the 4 inch dump into 3 inch mandrel....seems to work well...had it fabbed up in Wollongong. I would however suggest to you that they are available from beaudesert exhausts in qld...3.5 inch off the turbo and 3 inch to the rear, packaged up and sent to your address for roughly 800

dow50r wrote:I run the 4 inch dump into 3 inch mandrel....seems to work well...had it fabbed up in Wollongong. I would however suggest to you that they are available from beaudesert exhausts in qld...3.5 inch off the turbo and 3 inch to the rear, packaged up and sent to your address for roughly 800

Hi Dow50r,
thought Id read you had gone with 4" dump. Does yours follow stock exhaust route?
Did you use a braided flex joint?

Thanks for the tip on beaudesert. I know they get a good rap from lots of people, probably worth a call.

mate out of the 2 80 i have owned both having 3" from turbo to the front of the rear diff.

my first one had NO flex joint and used to vibrate against the chassis and snap exhaust mounts.

the currant one has a flex joint right near the front body mount and ive never had a problem with anything since owning it for 5 months now. i would say chuck one in for sure. mine only cost me $38.00 for a 3" 250mm long.

cheers mark

Ive just been under the cruiser with a piece of 4'' timber and tape measure to check out how much room there is for exhaust on the inside of the chassis rail.

to go from turbo straight through to the rear is actually a very direct route and I cant see any problem with getting 4" pipe past fire wall.

I was thinking of running 4" to just ahead of transfer and reducing down to 3" from there to the rear. this would give about 750-800mm dump pipe

there are two places where there is not a lot of room for this idea.
# in between chassis and bell housing flange is about 130mm so this would give approx 10-15mm clearance each side of 4" dump pipe (not sure on O/D of 4" exhaust pipe)

# in between transfer and chassis is about 90mm so there would be less than 10mm clearance with 3" pipe. the 3" pipe would have to dog leg slightly to follow chassis past transfer to improve clearance. I have looked at this a couple of times and it looks like a possible solution would be to redrill the gearbox crossmember so that rear of transfer sits 15mm further to the left. this would give about 15mm clearance to exhaust.

I am keen to run the exhaust this way coz it eliminates a heap of bends. without mufflers the only bends that would be tight at all are the last two to get past the diff.

I was thinking that passing so close to transfer case may be a problem with heat, but I know lots of petrol V8s run extractors and exhausts very close to gearboxes and petrols run a lot higher exhaust temps too.
I have already fitted two layers of thermal insulation under all the carpet in my cruiser so dont see heat under feet as much of a problem, can always add heat sheilds if it is.


can anyone see any problems with this idea?

Dave

mud4b wrote:mate out of the 2 80 i have owned both having 3" from turbo to the front of the rear diff.

my first one had NO flex joint and used to vibrate against the chassis and snap exhaust mounts.

the currant one has a flex joint right near the front body mount and ive never had a problem with anything since owning it for 5 months now. i would say chuck one in for sure. mine only cost me $38.00 for a 3" 250mm long.

cheers mark

Hey mark,

cheers for the tip. didnt think flex joint would be so cheap

your exhausts follow the stock route and then dump in front of diff?

i made my exhaust 3.5 dump pipe - 3 inch incorperated the exhaust in to the slider it ends before the back wheel

80's_delirious wrote:
Hey mark,

cheers for the tip. didnt think flex joint would be so cheap

your exhausts follow the stock route and then dump in front of diff?

mate honestly neither did i, yes the exhaust runs in the stock position and dumps before the rear diff.


also i can see 1 problem that could occur in your above post, moving the tcase to the left 15mm might cause you to have travetrain vibrations.

cheers mark