Adiver
Member Since: 18 Jan 2006
Location: Rutland
Posts: 492
  
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| Anyone Bi-turbo'd the D3 yet? |
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Anyone?
Jon D4 SDV6 HSE
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 4th Mar 2008 12:10 am |
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Bodsy
Site Sponsor
Member Since: 06 Nov 2006
Location: In the Clubhouse
Posts: 21361
  
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Wait for the 3.0l twin turbo at the end of the year......  Bodsys Brake Bible
D4/D3 Remote FBH heat kits
BAS Remaps/ EGR Blank
Transmission Flush
Software updates/enabling
Clock/ SNOTM /3Flash / 4x4Info /BT Update /Service Reset/Error Codes / Gearbox Reset
See It Here
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| 4th Mar 2008 1:05 am |
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1955diesel
Member Since: 08 Mar 2005
Location: Birmingham England
Posts: 31
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Bi-turbo was considered for the D3, but the single turbo gave more suitable power characteristics. Next generation will probably be sequential bi-turbo.
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| 4th Mar 2008 9:31 pm |
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Gareth
Site Moderator
Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26706
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Whats the difference?
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| 4th Mar 2008 9:50 pm |
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Gareth
Site Moderator
Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26706
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Maybe what I should have asked is whats significant about a sequential bi-turbo?
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| 4th Mar 2008 9:54 pm |
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90BHP
Member Since: 18 Oct 2006
Location: Half way along the road on the right
Posts: 3706
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very good  "To finish first, one first has to finish ...."
Last edited by 90BHP on 4th Mar 2008 9:58 pm. Edited 2 times in total
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| 4th Mar 2008 9:56 pm |
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DiscoStu
Member Since: 09 Apr 2006
Location: London
Posts: 11412
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Ah...
They come in at different sections of the rev range - so you get one for lower down/one for further up the rev range, giving you more power from a standing start - should do away with the initial lag....  Disco 5 HSE Lux
https://www.youtube.com/watch?v=peyiqaJrmMU
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| 4th Mar 2008 9:56 pm |
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Gareth
Site Moderator
Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26706
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| 4th Mar 2008 10:11 pm |
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Adiver
Member Since: 18 Jan 2006
Location: Rutland
Posts: 492
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Ok - so twin turbo then...anyone?  D4 SDV6 HSE
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| 4th Mar 2008 11:30 pm |
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Martin
Site Admin and Owner
Member Since: 06 Nov 2004
Location: Hook Norton
Posts: 18457
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Why?
The D3 has a bigger single turbo which LR deemed better suited to the Discovery, compared to the pair of smaller ones used in the Jaguars and Peugeots.
They wouldn't have changed it if it wasn't necessary.
The problem you would have is controlling two turbos, presumably you'd have to run a Jag/PSA V6 Diesel ECU, which won't have any idea about Terrain Response or any of the other LR-specific functionality.
It *could* be done, but there's really very little gain, if any, and a heck of a lot of integration work - it's not just a case of bolting on another turbo! 06 D3 SE / 15 LR D90 XS SW / 88 LR 90 Td5 / 68 BMW 2000 ti
Any issues with the site let me know!
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| 4th Mar 2008 11:57 pm |
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simon
Member Since: 11 Jan 2005
Location: Shropshire
Posts: 18296
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Why not add a NOX button to the dash instead 
That way you can go faster without any ECU integration at all and blow your engine to bits in the process.
After spending time with my MY08, I see little point now in actually doing anything to the engine... 35MPG and plenty oomph on the road once on the way.
It ain't supposed to be a sports car or a Gayanne
By a RRS SC if you need to
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| 5th Mar 2008 12:05 am |
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opodden
Member Since: 29 Jun 2006
Location: Elverum
Posts: 100
 
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Without being an expert on turbos....
A V6 is ideal for a twin turbo (1 turbo for each cylinder bank) because the power pulses are evenly spaced. One example of this is the Maserati Twin turbo.
A sequential bi-turbo uses a small turbo in the lower rev band, because it will spool up quickly and minimize turbo lag. When the revs rise, a bigger turbo will take over and produce the necessary boost that the smaller turbo is incapable of. A well proven example of this layout is the Mazda RX-7 turbo 2 from 1993 and up. It's definately not a V6, but it has a sequential bi-turbo setup. This car is very popular with tuners in the US. The best of them wring more than 500 rear wheel horses from the 1.3 liter rotary engine. Almost all high power cars I've seen has a single turbo conversion.
There are probably many reasons for this. One is that the system is complex with a lot of hoses and wires, which makes it maintenance intensive to keep in good nick. The original turbos are too small to provide boost pressure for big power. So it's probably easier and cheaper for most people to go for one big turbo. The aftermarket turbos being used are of a better quality than most OEM units, with ball bearing axles making them spool up faster than equally sized conventional turbos. The real pros would probably go with twin- or bi-turbo setups if it gave them any advantage, because them run advanced, stand-alone ignition and fuel injection systems, NOS etc. The fact that they don't, tells me that a more complex system doesn't offer any advantage in their applications.
But these are racing cars, either on the drag strip or other forms of track racing. How about our use, offroad and on public roads, in a heavy vehicle? If I were to seriously modify my TDV6, I could try to duplicate the Jaguar set up, but I'm pretty sure I would have a nightmare with engine management, packaging in the engine bay etc. I would go for an aftermarket turbo with ball bearing axle, paired with a free flowing exhaust system. This would be easier to integrate. I don't know if our car's turbo has variable vanes, but I don't think so. Introducing such a turbo would probably not be a good idea because the ECU wouldn't handle it. It might be a good idea to fabricate a new exhaust manifold, to decrease resistance and make the turbo more efficient, as the original manifold is maximized from a manufacturing cost perspective. A high quality turbo on a optimized manifold could offer faster spool up and more boost at low revs. It could at the same time be bigger and provide more boost at high revs. Of course the ECU would have to be reprogrammed in order to take advantage of the increased boost. On additional trick would be to have a NOS system to aid spooling up of the turbo at low revs, maybe using the kick-down signal? This would help in overtaking situations and other instances when you suddently have to floor it.
This of course raises the question why? And how much will the gearbox and the rest of the drivetrain take? If my turbo goes up in smoke in the future, I will probably look into a different turbo. But until then, I will maximise the existing setup by building a better exhaust system.
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| 8th Mar 2008 12:02 pm |
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Slimer
Site Moderator
Member Since: 06 Jan 2005
Location: Last Exit to Nowhere
Posts: 16295
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opodden wrote:I don't know if our car's turbo has variable vanes
yes, TDV6 in the D3 does AFAIR The End
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| 8th Mar 2008 1:14 pm |
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