Another exhaust question...

[Barrbeast]

So I removed my main silencer at the weekend as it was getting fairly battered at the weekend and had picked up a few leaks.

Replaced it with a straight stainless section and I've got to say the Trol definitely feels a lot livelier without that big jerry can hanging underneath. Exhaust noise isn't really changed either as there's still the small silencer at the very end.

But...

I'm tempted to go further, the end of the stainless section runs pretty near the centreline of the truck and actually past the front edge of the rear tyres (I reckon around level with the front edge of the rims). I've always thought the exhaust at the rear was a bit vulnerable and so I was thinking about just adding a 45 degree stainless bend to the end of the straight section and terminating the exhaust there with the end pointing towards the offside and down a bit.

Off course it might be too noisy (offroad site doesn't like noisy/missing exhausts as they annoy the neighbours) but I can maybe put the wee silencer from the end in earlier on in the system if that's the case. I reckon there could be a good spot after the flexi section (needs replaced anyway).

What do folks think about that point for the termination of the exhaust? :nenau

 

[makeitfit]

Would this be somewhere in front of the rear wheel then ?
I think there's some MOT requirement for the exhaust to clear the body and not exit under it. Gases in the cab and all that probably

 

[Sweety]

The reason the trol feels as if it's woke up a bit is due to the old centre box restricting gas flow:thumbs What I would do is disconnect the tail pipe for a couple of days to see what the noise level is like before ordering more parts:augie You can get free flowing centre silencers which will drop noise levels a bit without restricting the gas flow like normal silencers do

 

[Barrbeast]

Would this be somewhere in front of the rear wheel then ?
I think there's some MOT requirement for the exhaust to clear the body and not exit under it. Gases in the cab and all that probably

Far as I know MOT failure is "an exhaust tailpipe positioned so that fumes are likely to enter the driver’s or passenger area". I had a look under the truck tonight and the exit point would be passed the rear edge of the rear door and pointing directing the fumes away from the door and down (ish) :nenau

The reason the trol feels as if it's woke up a bit is due to the old centre box restricting gas flow:thumbs What I would do is disconnect the tail pipe for a couple of days to see what the noise level is like before ordering more parts:augie You can get free flowing centre silencers which will drop noise levels a bit without restricting the gas flow like normal silencers do

Cheers bud, yeh guessed as much. Actually already got the bits as I thought I might need the 45 bend when I chopped out the centre box :thumbs

I'm planning to fit the new flexi when I'm off on Friday so was thinking I could give it a check without any silencer then.

Checking the Aussie forums the 3.0 engine is apparently quite quiet anyway.

 

[makeitfit]

Ah right, couldn't quite place where you were exiting ? :thumb2

 

[Barrbeast]

Ah right, couldn't quite place where you were exiting ? :thumb2

No bother bud, took this pic once I had the straight section fitted. Angle's not the best but maybe give you an idea of where I'm meaning better (clamp nuts are near the end). Add a 45 degree bend pointing down part the way and I reckon it should be okay :nenau

 

[AlexD333]

I thought mine was gonna be super noisy, actually it's not that bad at all.

I also have a little section of pipe pointing out at the side. I'm tempted to go beyond the drivers door as the flexi is breaking up a bit :augie

It also sailed through its mot no problems.

Don't forget your 4x4s appearance gives it a better chance than a car for passing noise regulations,

You wouldn't expect a quiet tractor to drive past would you :nenau
See my point

 

[firebobby]

I know when I got my 3.0, the exhaust was in half on the flexi joint, after fitting a new exhaust, there was no difference in noise levels and only noticed the brake after crawling around underneath.

 

[macabethiel]

Exhaust Pack Pressure - do you need it for a Diesel Engine ?

Not sure if Diesel engines are different but certainly on a Petrol engine you need some degree back pressure in the exhaust sytem for the engine to work properly as you will loose power with no silencer system at all. The back pressure somehow assist in the induction stroke depending on the amount of valve overlap.

On my old 1967 Cooper S I fitted a works extractor exhaust and that upped the power quite a bit but it was very throaty.

Thus removing all the silencing boxes might make you loose power it certainly does on a petrol engine in my experience quite apart from the noise issue.

 

[makeitfit]

Aye quite different on a turbo diesel. No back pressure on the waste gate is good. Get out quick

 

[AlexD333]

Aye quite different on a turbo diesel. No back pressure on the waste gate is good. Get out quick

yup and a shorter exhaust means less likely to drown underwater on idle :sly

mine survived in the bog :naughty had it have been a full length i dont think it would have coped

 

[Sweety]

Not sure if Diesel engines are different but certainly on a Petrol engine you need some degree back pressure in the exhaust sytem for the engine to work properly as you will loose power with no silencer system at all. The back pressure somehow assist in the induction stroke depending on the amount of valve overlap.

On my old 1967 Cooper S I fitted a works extractor exhaust and that upped the power quite a bit but it was very throaty.

Thus removing all the silencing boxes might make you loose power it certainly does on a petrol engine in my experience quite apart from the noise issue.

One none turbo'ed engines petrol or diesel you need some back pressure which the silencer/s produce to get max power from your engine but on turbo charged engines it's the turbo it's self that produces the needed back preasure:thumbs