Audi A8 D2 1.2 TDI?

[Vekke]

Audi A8 D2 1.2 E-TDI

Hi,

I finally was able to buy my next project car and its 1997 Audi A8 with 2.5 TDI and 6 speed manual gearbox.

Target for this car is to reach 3liter fuel consumption at 100 km/h speed (78 MPG us at 62 MPH)

Project pictures can be found :https://www.facebook.com/media/set/?set=a.726508297363058.1073741829.163711023642791&type=1

I will install a 1.2 TDI engine from lupo to this later this year, first some aerodynamic improvements and test with the base car.

Target specs:
1.2 TDI with 144 hp and 350 Nm
weigth: under 1400 kg
Cd 0.22
3l/100 km at 100 km/h speed
3000 km on one tank
Acceleration: Faster than Audi S8 with 400-500 Nm electric motors to rear axle (summer 2016)

 

[VeeDubTDI]

Vekke, I'm definitely interested in seeing this!

With a 1.2L in the A8, you should be at the best part of the BSFC chart almost all the time. I expect great results.

 

[TomJD]

A 1.2L in an A8? Will it have trouble moving the car?

 

[PressEnter[]]

neat idea. I'm in for updates.

 

[PressEnter[]]

A 1.2L in an A8? Will it have trouble moving the car?

Shouldn't if he hits those target specs.

 

[VeeDubTDI]

It isn't going to win any stoplight races, but it should be able to hold its own on the highway and return some very impressive fuel economy numbers. Talk about a great road trip machine!

 

[TDIMeister]

I guess this will be a series hybrid, but without the extra weight of batteries, so essentially like a locomotive?

Neat idea! Your challenge I think will be in the power electronics and dialing in the calibration. The rest will be relatively straightforward.

I'll be happy to give assistance if requested.

 

[Vekke]

Yes it will be quite fast like the Lupo. Total torgue for next summer 2015 will be 750-850 Nm in accelerations. Already with 1.2 TDI alone it will be faster than with stock 2.5 TDI setup.

You only need that 10-20 hp on highways speeds.

I am not the first one to build this kind of car: http://www.wardtro.de/html/3l_audi.html he has little different setup gearbox wise and stock power 61 hp. His car is in use at the moment.

 

[Vekke]

Project has moved along nicely at the end of year 2014.

Changed Audi A4 B6 front structs and brakes. Weigth BOM is showing total of 1434 kg. So its pretty close already the first weigth target.

Engine is sitting already in the engine room, turbos and its piping start to be ready. custom exhaust piping done. Wiring harness is ready for install which day should be at this week.

Oil pan still needs little work as its leaking little bit. So I still have to take the engine out at least one more time before first start.

I have also made some new calculations based on BSFC map data and at this stage that 3 liter target is looking much easier than the two liter target in the lupo 2L project.

 

[Vekke]

ITs alive!. 1.2 TDI engine started today for the first time in the A8 engine bay. So in my point of view the most difficult task so far seems to be conquered.

If everything goes smoothly at the inspection this baby will hit the streets within few weeks!

 

[VeeDubTDI]

Outstanding! I'm looking forward to seeing videos.

 

[Windex]

Is the instrument cluster working - all gauges?

Any Check Engine light on?

 

[Vekke]

Yes there is still some warning signal blinking but not all accesories were attached like altenator for exhample. RPM works, water temp, oil temps seems to work. Fuel gauge working. Old gas pedal works. Everything else should work as well as everything is connected.

Today got all water hoses attached and it was a huge job to figure out which hose should go where...

Tomorrow try to install AC and power steering pump plus the belt if I have correct length in my garage. Anyway the car should be in driving condition tomorrow.

 

[TDIMeister]

Very cool! Is it connected to an 01E transmission? Does your A8 retain quattro? Have you changed the transmission ratios to get even better fuel consumption? What code is the transmission?

 

[Windex]

Interested in the above as well.

Finally an Audi chassis where the Timing belt can be done without putting the front clip into the service position!

 

[Vekke]

This was and at the moment only is a front wheel drive version (will be a 4wd when its ready).

My gearbox is at the moment CYB which it had from the factory. So 3.85 final and 0.60 6th gear. As you can see from that BSFC chart above I will have in first swap the 3.85 final plus 0.56 6th gear in 01E. So I will swap the DQS gearbox from A4 B6 2.5 TDI 2001 model. But the gearbox that I will try to source and find cheap is, 01X with 3,56 + 0,56 6th gear There is not that box with that gear setup from the factory so I will have to build one from two boxes. That 3,56 final is 8% taller compared to 3,85 which makes all ratios taller plus that 01X is about 11,3 kg lighter is data on the internet is rigth. Which is icing on the cage. Sad thing is that those are found only on VAG 2004- or so models and are more expensive and rare to find cheap. I am not 100% sure at the moment is there a 0,56 6th gear that will fit the 01X gearbox as you have to gather data from here and there.

01X JWS would be best option if you dont want to open the box as it has 3,55 + 0,575 so the 0,56 would only be 2,6% taller.

I will propably use 195/65R15 tires but best tire is found in tests. I have 5 sets of wheels for this car...

 

[TDIMeister]

Are you going to do any modifications to that engine? I mean 61 HP to move 1434 kg plus driver and passengers) is not going to be much. If so, keep in mind that your BSFC map no longer looks like that when you start changing things in the engine, like the turbo, injectors, mapping, etc.

In the interest of maximum fuel economy, retaining FWD will be better anyway.

 

[Vekke]

If you have read the first post yes I will tune and modify the engine. Target is 144 hp and 350 Nm, but I disagree that the BSFC map will change to worst, that is how you ECU tune it of course, if you know what you are doing... In the lupo I already had 120 hp and 285 Nm and not much harmful effect to fuel consumption as I was able to reach that 2 liter 117 MPG us fuel consumption target.

At the moment Engine specs are:
560er injectors
Passat B6 pump duse exhaust manifold
VNT-15 at the moment but that will change later to 1749VA
intercooler A8 original, but will build/install watercooler system
Oil pan and its suction modified.
Rigid flywheel is 240mm with sach race pressure plate and LUK 240mm disc
Maybe a camshaft update later this year

 

[cumminsfromthecold]

Subscribed. Very cool build. From what are the electric motors that you're looking to use at the rear wheels?

 

[Vekke]

This is finally on the road and fuel consumption is already looking great without any major aerodynamic mods.
4.24 L/100 km
55.55 mpg (US)
66.66 mpg (Imp)
1.8 gal (US)/100 mi
606.69 Wh/mi

Tried to drive 100 km/h or 62 MPH speed as much as possible but in the beginning there was 50 km of traffic light driving which hurt the FE.

 

[Windex]

How is the performance on hills with passengers and a full tank?

 

[Vekke]

This is fast enough so no problems. 60-120 km/h acceleration takes 10.5 seconds. At the moment car has 120 hp and 285 Nm of torgue and more will come

Car weights 1470 kg with full tank at the moment and gets even lighter.

This can reach 4 liter fuel consumption at 100 km/h speed at current state that means 59 MPG US at 62 MPH speed, but it will get better(lower) each week.

 

[VeeDubTDI]

Those are impressive results, and I'm sure they will improve as you get things dialed in.

 

[Vekke]

Today already 3.92 liters which is 60 MPG us. Next step is 3.5 liters --> 67 MPG us.

 

[1854sailor]

Pictures, please!

 

[Vekke]

Link to all pictures is in the first post on this topic.

 

[VeeDubTDI]

Must be logged into Facebook to view pictures.

 

[Vekke]

Next month I will break some records with this project.

 

[tikal]

Tell us more about the oil you are using. Any friction modifiers such as tungsten disulfide (WS2) or similar nano technology?

 

[Vekke]

No additives at the moment. I will put the ws2 to engine oils in next change. I have broken 2 gearboxes so will think shall I put it also in this gearbox