3" exhaust

[squidsd1]

is there a large difference in performance between a 3" straight through exhaust and standard exhaust with center muffler removed and straight through resinater on a 300tri disco

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[weeds]

I have standard size straight through no muffler or resonator

I'm not sure you will gain much if anything with a 3"

[squidsd1]

is it noticeably loud with no boxes at all do u notice the change in pick up, fuel economy , highway drone?

cheers

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[*RR*]

the standard system has a few step downs, I think the smallest is just over 2.1"

3" has 50% more area then a 2.5" pipe...

2.1" = 13.8^2"
2.5" = 19.6^2"
3.0" = 28.3^2"

[redrovertdi]

yes, when the 3in pipe was fitted with one large muffler only in the centre, the turbo spools up way faster however you have to tune the injector pump to suit to gain more power[boost needs fuel], after tuning at MR the economy was better to, previously i had a standard pipe with centre muffler removed

[*RR*]

yes, when the 3in pipe was fitted with one large muffler only in the centre, the turbo spools up way faster however you have to tune the injector pump to suit to gain more power[boost needs fuel], after tuning at MR the economy was better to, previously i had a standard pipe with centre muffler removed

My dad runs a 3" and bigger cooler on his 300 without touching the pump and he reckons it made a world difference, mainly in the bottom end and mid range.

[redrovertdi]

My dad runs a 3" and bigger cooler on his 300 without touching the pump and he reckons it made a world difference, mainly in the bottom end and mid range.


The first performance upgrade i did was a full front allisport/allard intercooler, it made no noticeable difference at all until the pump was tuned to suit

[*RR*]

The first performance upgrade i did was a full front allisport/allard intercooler, it made no noticeable difference at all until the pump was tuned to suit

No idea, dude. Just relying what the old man has told me...

[disco971]

get better intercooler hoses too, the factory ones always used to get soft and restrict performance.
3" from the turbo down to a 2.5" should work well.

[*RR*]

get better intercooler hoses too, the factory ones always used to get soft and restrict performance.
3" from the turbo down to a 2.5" should work well.

that could work too...

the exhaust is just under 2.5" from the centre back and the down pipe is about 2.1" off the turbo...

[slug_burner]

the standard system has a few step downs, I think the smallest is just over 2.1"

3" has 50% more area then a 2.5" pipe...

2.1" = 13.8^2"
2.5" = 19.6^2"
3.0" = 28.3^2"

Are you sure?

A = pi.r^2 or pi.(D/2)^2 the pipe dimensions I believe to have been expressed as diameters.

I'd say if we looked we could find an expression of resistance to flow for a given pipe size, no doubt that a bigger pipe will offer less restriction but there is a stage at which you will get diminishing returns.

[squidsd1]

3" and intercooler upgrade and proper tune sounds like the go. does any and have torque figures or know what actual power the 300tdi makes with those kinds of mods ? kw/nm

cheers

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[Blknight.aus]

you dont NEED a 3 inch exhaust on the tdi300, a 2.5 thats mandrel bent is enough, however..

its cheaper to get a standard 3 inch job done in place and thats got the same effect.


theres no point in fitting up any of that stuff unless you sort out the dump from the turbo first, I get to see a lot of 3 inch exhuasts that still hook up to the standard turbo dump pipe.

[squidsd1]

would most off the shelf exhaust pipes come with larger dump pipe?

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[kadine94]

Ive taken out the centre muffler and the resonator.Dad says put resonator back on ,you wont lose any power,is he right?Have only wound smoke screw up 1 1/2 turns so far.Better take off,its an auto.

[*RR*]

Are you sure?

No, ****. I shouldn't come on here when I'm tired.

2.1" = 3.46"^2
2.5" = 4.91"^2
3.0" = 7.06"^2

the fact still remains that the 3" pipe has almost 50% more area.

[squidsd1]

so is the 3" too big or is it just as beneficial to removed center muffler?

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[rick130]

so is the 3" too big or is it just as beneficial to removed center muffler?

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No, not too big.

If the Disco uses the same/similar centre box to a 300Tdi Defender, they are a straight through, perforated tube type muffler anyway so IMO any increase in performance from removal is a placebo.

A large pipe will drop EGT's and help off idle spool up.
my 3" Defender system dropped maximum EGT's by 25* which gives more scope for pump tuning.

In a Defender with a longer exhaust it also enables a much improved rev range through the gears as the stock 60mm/2.375" system while well made is a tad restrictive.

[rick130]

theres no point in fitting up any of that stuff unless you sort out the dump from the turbo first, I get to see a lot of 3 inch exhuasts that still hook up to the standard turbo dump pipe.

A bit hard with a 300Tdi as the dump is cast as part of the turbine housing, but what can be done is throat the dump internals to match a 2.5" pipe and taper the 2.5" pipe to 3" nicely.

That works well.

[tassydisco]

I had a 3 inch stainless with a straight through muffler on my 300tdi. Made a noticable difference down low especially. The droning on the highway sends you bonkers though, I wouldn't do it again simply because of the noise inside at highway speeds. Maybe invest in some good earmuffs? :D

[squidsd1]

tasty disco, did u get much difference in fuel economy ?

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[Spel1]

If the Disco uses the same/similar centre box to a 300Tdi Defender, they are a straight through, perforated tube type muffler anyway so IMO any increase in performance from removal is a placebo.


The 300TDI Disco is not a straight through muffler. It looks like it from the outside - same apparent entry and exit points - but there are a series of baffles in the middle. I took mine off a couple of years ago (checked it then) replaced with a straight though muffler which slipped over the original pipe. Left the resonator in place also. No noticable increase in noise, no drone, but does spool up a bit quicker with slightly lower EGT's.

[squidsd1]

that sounds like the go , replace the centre muffler with straight pipe .

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[rick130]

I had a 3 inch stainless with a straight through muffler on my 300tdi. Made a noticable difference down low especially. The droning on the highway sends you bonkers though, I wouldn't do it again simply because of the noise inside at highway speeds. Maybe invest in some good earmuffs? :D

You definitely need a resonator along with a large muffler with a 3" system otherwise the noise and drone is awful.

I made the mistake of building the system initially with no silencing whatsoever and it was horrific in both noise and resonance.

[tassydisco]

tasty disco, did u get much difference in fuel economy ?

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Not sure if it changed I can't remember, it did 10l per 100km on highway, close to double in town. Turning 35 inch tyres and all sorts of other clobber so not sure if it's a very accurate test.;)