4020

fastfarmall · Feb 21, 2021

Why did the last 4020 John Deere's, have that small exhaust pipe on the later ones?

SVcummins · Feb 21, 2021

Better visibility

WTW · Feb 21, 2021

It was called exhaust tuning / back pressure. Tractor would produce more power more efficiently with tuned exhaust. I have seen a 4040 on dyno loose 5 hp by removing muffler and running with a straight pipe. Owner thought the chrome pipe was cool till he seen that and put muffler back on.

fastfarmall · Feb 21, 2021

Well did they continue that practice,with the 30,40 and up series?

SVcummins · Feb 22, 2021

I thought the chrome pipe was cool too for a few years but even with ear muffs I could still here that stack when I went to bed at night but it did sound good

SVcummins · Feb 22, 2021

No more round mufflers on the big tractors anyway until you got to the real big tractors then they had round again the 30 and 40 series 4wd with the stacks still in the hood had oval mufflers

WTW · Feb 22, 2021

Only on NON turbo models.

ss55 · Feb 22, 2021

Acoustics and noise reduction, high noise levels for the operator started to be a concern around 1970. Noise levels were starting to be recorded in the Nebraska tractor tests. A few years later quiet cabs were in big demand. Nearly new tractors were being traded in to get a tractor with the new cab.

Robert (ID) · Feb 23, 2021

HUH??? whats that?? I cant hear you, you need to speak up.... WAY too many hours on howling tractors with straight pipes...

SVcummins · Feb 24, 2021

Yes but they sounded good when the front end starts coming off the ground a little bit and she really starts to pull

4020

fastfarmall

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SVcummins

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WTW

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fastfarmall

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SVcummins

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Robert (ID)

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