Exhaust set up in an 80

Joined: 02 Jul 2003 Location: Baulkham Hills

What sort of exhaust set up have people got in their 80's? Looking to do something regarding mine in the next week or so. Can you notice the difference with a mandrel bent system?

Joined: 17 Aug 2003 Location: Cairns, (capital of Nth QLD)

Petrol or diesel ?

I have a 2 1/2" mandrel bent exhaust with no mufler. Very Happy

Also a mate has a 4.2L Patrol with 3" mandrel bent exhaust with no muffler but thinks 2 1/2" is all thats needed.

With a turbo you don't need a muffler as much so you get a nice note.

I never drove mine with standard exhaust but am told the factory exhaust pipe is crushed restricting the flow in some places.

Joined: 02 Jul 2003 Location: Baulkham Hills

Yeh, she's a diesel. That's half my reason for getting dome new exhaust work done. You are correct, the factory pipe is squashed in some areas.

Joined: 12 Aug 2003 Location: wollongong

DX you will notice an improvement getting a new muffler more than a new system, over the rear xmember is squashed, so a new rear aswell.
If you are looking for a good value for money imporovement, get a turbo for it, either preloved or new, depending on how good you are with mechanical things.
Andrew
ps yes to your pm

Joined: 02 Jul 2003 Location: Baulkham Hills

Yeh got no dramas with mechanicals, just wanna get what should be a good diesel going just a bit better. Options open if you here of a good rebuilt second hand turbs.

Joined: 21 Oct 2002 Location: Near Mt D.

Take the standard exhaust off at the flex - get a non mandrel 2.5" straight through and make sure they dump it next to the spare tyre - no more bends! (not over/under teh rail again under teh rear 1/4) Get a high flow stub Muffler and away you go. all up I spent $250 and love the note, the punch you get.

I do not advice a mufflerless setup unless you have the turbo - I did it for 2 weeks and well - I was very, very very loud - 120+ decibels... Set car alarms off in S/C's.... went deaaf etc - could only drive at 80 or 120....

maybe open the pump a tweak on a dyno once its done to make sure you have the go factor. armsup

Joined: 02 Jul 2003 Location: Baulkham Hills

So the new system went in yesterday. A non mandrel bent 2.5" with a hi flow muffler, cut from infront of the old resinator. Got a real sweet throaty note to it now and can notice a little difference going through the gears. So my question now is, has anyone got extractors as well, and is there a more noticeable boost with a set, or bugger the extractors and work towards a turbo? The shop put this 3" chrome tip on the end which I'm not so sure about, looks like a bit of a wank, didn't pay for it, they recon the gave it to me for nothing, so might do away with that.

Joined: 02 Jul 2003 Location: Baulkham Hills

Chrome tip is now gone. Couldn't stand looking at it. It looked like Julio the street racer.

Joined: 17 Aug 2003 Location: Cairns, (capital of Nth QLD)

Chrome tips apparently rust the exhaust pipe so stainless steel should be used instead but personaly don't think there needed on a 4by. Wink

I you don't intend on going for the turbo id defenatly go for the extractors, the 1hz has a very basic cast exhaust manifold that looks like a big restriction.

BTW- did you keep the exhaust flex joint near the engine ?

Joined: 02 Jul 2003 Location: Baulkham Hills

Yep, kept the exhaust flex joint.

Joined: 21 Oct 2002 Location: Near Mt D.

My housemate has a set of extractors on his 80 - makes a difference as it picks up the bottom end grunt and makes long hills easy as - it essentially brings the backpressure back to the engine so it has more torque as well as freeing up the the top end. Worth getting - its on my shopping list next as well. Cool

Replace the flexi when you do the extractors. Worth the extra $150.00...

Joined: 17 Aug 2003 Location: Cairns, (capital of Nth QLD)

80diesel4play wrote:

it essentially brings the backpressure back to the engine so it has more torque as well as freeing up the the top end.

I thought extractors reduced backpressure ?

If you have tuned length extractors the exhaused from each cylinder theoretical sucks the gasses from the other cylinders that are in the combustion stroke allowing less backpressure on the engine, this is called "scavenging"

Well thats how i think it works anyway ! Rolling Eyes

Joined: 21 Oct 2002 Location: Near Mt D.

I mis quotyed myself - scavenging is the correct term- after the high flow exhaust moves the back pressure point further down the piping... The extractors assist - one thing with scavenging - they will pull oil up into the exhaust - so a good dyno tune would be advisable...