D3/D4 Power Upgrades up to 300hp on the tyres

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Originally Posted by josh.huber

If I quote a website it would be one of substance. I agree and wrote there is allot of yeah making claims online. I'm sure it's in a trade manual I have at home in Newcastle. I can't wait for Mitchell bros to reply to this thread maybe they can put a d4 on with and without a bigger flowing exhaust and give us some readings

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If you plan to make any changes, you need to fit the gauges and baseline first.
Before you change anything.

Yeah for sure I might give the tuner another call and ask if they will before they do their next one

And estimated cost?

$3800 exhaust (stainless but the low grade) and remap

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Originally Posted by josh.huber

Landrover Discovery 4 3.0L (R&D Vehicle Needed) : TaipanXP they are in the gold coast, seems we are a target for accessories finally

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Note the date this page on the website was posted - 5th April 2013. Nobody interested in having an aftermarket exhaust for nearly 1 year!
Nobody?!

I was on their site august last year when I bought mine and didn't see it then.

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Originally Posted by Dougal

There is endless BS about exhausts in print and on the net.
If you really want to know, then measure your current exhaust back pressure and see how "restrictive" it actually is.

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Couldn't agree more. I'd like to know what's wrong with the standard exhaust.

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Originally Posted by josh.huber

Dougal Ill keep searching, but I have a website or article somewhere or maybe a book at home, that states that significant exhaust size does lower exhaust temps. As a much less restricted exhaust system aids in the scavenging effect on the engine (valve overlap and boost) allowing cooler air to flow over the top of the piston and through the cylinder. I think exhaust shops make claims to this in ways that make it unbelievable but. Yes it is true, looking around last night many shops won't remap without an exhaust upgrade.

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None of this stuff is simple and fitting a larger exhaust is not always a good thing. I'd be wary of any claims of improved scavenging as basically that is all happening before the turbo and I seriously doubt that the standard exhaust is so restrictive as to affect that. Also a turbo motor generally benefits from a little back pressure to help control the flow of gas through the impeller and prevent boost creep.

I don't know much about the specifics of the disco exhaust system, so I'm generalising. I'm just trying to say, be careful. Claims of increased power from an exhaust system can be dubious as a few extra kWs at the top end may come at the expense of mid range torque. Personally, I think $3800 is a lot of money to spend on reducing your ground clearance.

Cheers,
Jon

I have never performed any scientific tests RE disco3 exhaust system flow/ restriction etc, HOWEVER, Landrover engineers spend many, many hours of analysis and design on this and quite frankly I would be reticent to swap out any exhaust system without a decent amount of analysis and measurement, IE backpressure figures under ALL load conditions like Dougal has mentioned already.

A few years back I thought I knew better than Lexus engineers, and removed the rear resonators on my LS400, and enlarged the pipework. Result? Nicer V8 sound, but NO performance increase and an annoying drone at 100km/h.

Just be careful, as Gordon says.


JC

I have put in a remap from Davis Performance Landies with Active
they claim about 550nm now
must say it goes like stink and from a lot lower rpm
TDV6 2.7

Hey chaps

I'm in melbourne, just got a roo systems re-flash done. Apparently first one in Victoria. Only been a day. I had the de tuned landrover. The 520nm one.

A while back we at this forum came to the conclusion that the low spec model had different injectors, the mob at Roo claim they haven't. The parts search and landrover which was done on my vin number also suggested the same replacement part for injectors. Point I'm trying to make is Roo claim both specs tune up the same. I can't prove this however I can give a short summary of my on the road experience....

Firstly no noticeable change down low..... That doesn't mean there is none just didn't notice any.

Mid range- wow!!!!! It's a different animal, pulls like train!!!

Top end - wow. Also seems amazing. Just revs out so much easier.

The car now seems to rev so much easier and keeps pulling. Previously it felt quite flat up top and would run out of steam.

Without meaning to sound strange. It feels more petrol like. Just revs easier and relentlessly. I was hitting 100km very easy. Obviously booting it. As for torque I assume it's increased as to make a 2.7 t vehicle get up and boggy would require a boost in torque.

Unfortunately i didn't get a dyno result. They didn't offer it as part of the service. Apparently in Queensland you do get one... I'm disappointed that was the case but reasonably happy with the result nonetheless.

One of the added bonuses I felt was a slightly smoother more refined revving.. Kind of seems electric in its delivery.....

Please remember this summary is my opinion, I dont claim to be right, there are no measurement before or after, just plain old seat of your pants feel....

Thanks for reading

Bill