HDJ 100 4.2 TD upgrade ? (1 Viewer)

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Mar 26, 2012
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Perhaps there is a different spec in australia bit in europe, the catalyst is in the downpipe. One of the popular mod is to replace with a downpipe that doest (so called african spec in france)

View attachment 2586105
Apologies, I read d***pipe and assumed dump pipe... related but different. People don’t normally talk about just the down pipe, whereas the dump pipe is often mentioned separately.

As workhorse says - replacing parts of the exhaust is illogical. Just do the whole lot. It’s replacing one Tyre at a time
 
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I’ll play devils advocate here - I don’t think there’s much to be gained changing the dump pipe. It’s actually 2.75”, and most tuners here (Australia - the land of the landcruiser) say the dump pipe is not restrictive and doesn’t make a measurable difference swapping out to a bigger one.
It would be really good to do some back to back testing, but its a lot of stuffing around to get actual evidence. It probably doesn't make a lot of different with the stock turbo, but if you're putting a better turbo on I would recommend upgrading it.
 
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. It probably doesn't make a lot of different with the stock turbo, but if you're putting a better turbo on I would recommend upgrading it.
Yes, I agree - but people often make a big deal over it. I’ve spoken to tuners who have actually done back to back tests when tuning a uni chip and couldn’t measure a difference. It was the stock turbo though...
 
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I wonder if the FTE dump pipe is better flowing than the T/FT?
And I guess that means you could run a 2.75” exhaust with no performance hit, expect it’s probably more expensive/harder to find 2.75” Mandral bends compared to 3”...
 
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I wonder if the FTE dump pipe is better flowing than the T/FT?
And I guess that means you could run a 2.75” exhaust with no performance hit, expect it’s probably more expensive/harder to find 2.75” Mandral bends compared to 3”...
I don’t know about the dump on the earlier ones, I assume they’re different. A 2.75” exhaust would flow noticeably less than 3” I reckon - flow restriction is a function of diameter and length. The longer pipe Amy fluid travels in the more edge friction it encounters, likewise Diameter. The reason the 2.75” dump doesn’t restrict noticeably is mostly because it’s so short. Also, because the exhaust gas pressure is high to start with and it expands as it moves through - I think it’s more important to have a larger exhaust later on as it’s expanding
 
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From all my different exhaust and dump set-ups I've tried nothing made more of a change than just the dump section on its own. I've also worked with a few local diesel tuners and they also confirm that the dump and section soon after plays the most important part and the rest of the system further down is barely measurable with only the exhaust note being the main difference.
 
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AussieHJCruza

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From all my different exhaust and dump set-ups I've tried nothing made more of a change than just the dump section on its own. I've also worked with a few local diesel tuners and they also confirm that the dump and section soon after plays the most important part and the rest of the system further done is barely measurable with only the exhaust note being the main difference.
I agree, get an exhaust that includes the dump pipe (bolts to back of turbo) or don't bother at all. I ran my HDJ80 straight piped with stock dump, factory diameter pipe and there was a marginal improvement in performance. Put on a 3" dump and 3" exhaust, night and day to drivability
 
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Ok thank you. I think that is it: new dump pipe and unichip. That will give me the target torque improvement. Will report when I am done
 

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