Hi Guys, Just a question about exhaust system for my Navara 2.5 TD. I have had a DC chip fitted, this has made a difference to KW, Tourque, & some extent fuel saving, would fitting a 3" system make a further difference? should it be fitted with a Snorkel ?
Hi, Normally putting on a bigger pipe would be a good idea however having had the engine chipped I would contact the Chip people as I would expect the chip would be 'Mapped' to the standard exhaust.
DC should give you advice on that.
Snorkel,there are many schools of thought on that subject but one of the big considerations is the type of road you will be driving on.Dusty roads and a snorkel would help engine life by keeping dust ingestion to the engine less and keeping your air filter from clogging up so much.
I expect you will get more advice and I hope you get some good advice from the DC chip people.
Hi Guys, Just a question about exhaust system for my Navara 2.5 TD. I have had a DC chip fitted, this has made a difference to KW, Tourque, & some extent fuel saving, would fitting a 3" system make a further difference? should it be fitted with a Snorkel ?
your comments would be appreciated
Cheers
Miroku12g
G'day Miroku12g, along with the replies to be found here, have you checked the 4wd forums? (4wd action is one) They often have reviews on the items you have mentioned.
Yuglamron's comment re "mapping"is correct as I understand it and changing size of exhaust would require remapping.
Something that is often overlooked when modifiying our vehicles is the requirement to notify insurers, both for replacement in the event of accidents and or if vehicles warranty is effected by same...perhaps something to consider?
Regarding snorkels - any supposed advantage in breathing with a snorkel will be negated by the over boost protection built into all modern vehicle diesel motors (waste gates etc.) If you want extra boost you can fiddle with this cheaper than installing a snorkel.
The two advantages of installing a snorkel are:
1. Dust. The concentration of atmospheric dust is less at the snorkel inlet height than at the normal intake. The atmosphere at the higher level is never dust free, just less than the lower level. To really make a difference you need to install a Donaldson centrifugal filter at the top of the snorkel. I had one on my first Disco. The only time I collected any significant amount of dust in the filter was during sustained travelling on gravel roads with heaps of oncoming traffic. Even then I collected so little that I decided that I would not fit a snorkel on future vehicles, I considered the air filter would cope for my travelling. The Donaldson filter is a benefit if you are consistently in mining areas. You will note all the mining machinery has them.
2. Water. Diesel motors die very quickly when they take a drink. Snorkels are the way to go if you are travelling through copious amounts of water crossings.
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PeterD Nissan Navara D23 diesel auto, Spaceland pop-top Retired radio and electronics technician. NSW Central Coast.
I would recomend you don't blank off the EGR on a Nissan Diesel, you can do damage and make your vehicle non compliant to EPA regs rendering it un-roadworthy. And don't think the police don't know of these mods because they do a lot of the time and will send you to have it tested at a fairly hefty cost to yourself.
I know I have been there.
The EGR only works on deceleration so it does not effect boost so there is little to no advantage to blocking it off anyway.
Land Rover TD5 owners block off their EGR to reduce boost loss through the EGR valve as it's prone to failure, but again this is a minimal increase and the engine was far ahead of the Euro 1 emissions targets when built so they can get away with it.
On the side of the Exhaust, a free flowing exhaust regardless of the size will decrease the spool time of the turbo only, it wont effectively increase power.
On my Diesel Disco I removed the large restrictive center muffler and fitted a hotdog which massively increased acceleration off the line but did nothing for over all power.
The power output is controlled by balancing fueling and boost to engine speed and load so if you do fit a larger free flowing exhaust I would look at re-calibrating the DC chip as you may find it leans out on acceleration so EGT's (Exhaust Gas Temps) may climb under load.
For increased power it may be well worth you looking at a larger more efficient inter cooler and maybe LPG injection but with the later I would also fit an EGT guage to keep an eye on the temps.
As far as a snorkle goes, they don't increase power, most actually reduce power but they are a bit of an insurance policy when doing any river (or flood) crossings and will on dirt roads (on a Nissan where the intake is next to the front wheel) reduce dust ingress to your air cleaner which can greatly effect power and can reduce the life of both the air cleaner and the engine.
