Boxster V8 - Audi 4.2L 40v V8 Swap Information

2003 Boxster base 5 speed manual. Originally purchased with an engine that suffered from an IMS failure. I replaced that engine with a very low mile stock 2.7L that I bought from eBay. I put 7k miles on this setup before starting my Audi V8 swap.
I'm doing this swap because I want something fun, that not many people have. In 2018, I took the car with its stock engine to Hallett Motor Racing Circuit in Tulsa, Oklahoma and loved every minute of it! The stock engine, however, didn't. I had oil injestion issues on hard left hand, high G corners and it just wasn't very fast. The engine just wasn't conducive to track driving. I could have spent a few thousand dollars making it capable of sustained track driving but I wasn't keen on that idea. I wanted an engine that I wasn't afraid of running hard at the track and possibly loosing, since they can be had for very cheap compared to Porsche engines. I bought my Audi engine for $250 compared to the Boxster 2.7L that I bought on eBay which cost me $4000. Plus 355 BHP versus 227 BHP, that's a gain of 128 BHP!

Engine Information

My engine is from a 2002 Audi S8, engine code AYS. This is a 40 valve timing belt engine, factory rated at 355 BHP and 317 LB FT.
I'm using the stock Boxster front engine mount and location. I made a custom bracket that attaches to the engine via the A/C compressor and PS bracket bolts (see photos). I deleted both A/C and PS. The rear engine (transmission) mounts are also stock but have been lowered to allow the intake manifold to clear the engine cover, albeit with a minor modification to clear the PCV valve.
The accessory belt I used for no A/C or PS is a Bando 6PK1510.
If your V8 engine was originally an automatic trans car, there will be a spacer on the crankshaft between it and the flex plate that needs to be removed to install your flywheel.
I'm using a stock Audi A6 4.2L intake tube, along with a few various couplers and silicone hoses to put the MAF close to the drivers side scoop, where the factory Boxster intake sat.

Which Engines to Use

The following are all 40 valve, timing belt, engines from VW/Audi (still trying to verify that the DME information is correct):

Code Platform Power output DME Notes

3.7L Variants
- AQG, AKC D2 Audi A8 260 HP (191 kW) 258 ft lb (350 Nm) ME7.1
- BFL D3 Audi A8 276 HP (206 kW) 266 ft lb (360 Nm) ME7.1.1
4.2L Variants
- ARS, ASG C5 Audi A6 295 HP (220 kW) 295 ft lb (400 Nm) ME7.1
- AXQ VW Touareg 306 HP (228 kW) 302 ft lb (410 Nm) ME7.1.1 Deeper sump, 2 stage oil pump*
- AUX, AWN, AQF D2 Audi A8 306 HP (228 kW) 302 ft lb (410 Nm) ME7.1
- BGH VW Phaeton 329 HP (246 kW) 317 ft lb (430 Nm) ME7.1.1
- BFM D3 Audi A8 335 HP (246 kW) 317 ft lb (430 Nm) ME7.1.1
- AQJ, ANK C5 Audi S6 335 HP (250 kW) 310 ft lb (420 Nm) ME7.1.1
- AQH, AVP, AYS, BCS D2 Audi S8 355 HP (265 kW) 317 ft lb (430 Nm) ME7.1.1
- BCY C5 Audi RS6 450 HP (331kW) 413 ft lb (560 Nm) ME7.1.1

* SSP341, pg 20-21

My Audi DME Information

There are 2 flavors of DME for this engine, ME7.1 and ME7.1.1. My DME is 7.1.1 but it is important to be aware of which version you have. See the "ME7.1/ME7.1.1 ECU Pinouts" link above, as well as the section right above this.
The immobilizer has been turned off and is currently running a custom flash tune by Aaron Walizer. I highly recommend that you use him if you're attempting this swap. Contact him through Facebook at "https://www.facebook.com/aaron.walizer.7". Thanks, Aaron!
The Audi DME harness has been stripped of unnecessary functions and is running with only the following components:
- Front O2 sensors
- Injectors & Coils
- Knock sensors
- VVT
- Crank & cam position sensors
- Intake manifold changeover valve
- Coolant temperature sensor
- Mass airflow sensor (MAF)
- Drive by wire (DBW) throttle pedal & throttle body
The Audi DME is controlling the Boxster DME relay and fuel pump relay.
The stock Boxster DME is retained to operate the dash for the coolant temp and tachometer, and the engine compartment fan. The only inputs to the DME are coolant temp and crank signal.
- To run the Boxster CANBUS tachometer, wire Audi ME7.1.1 pin 90 to Boxster DME pin 45. What you are doing is sharing the Audi crank position signal with the Boxster DME which in turn tells the tachometer in the dash how fast the engine is spinning.

DME Flashing

READ through the first link in the "Threads of interest" section. Nefmoto is the go-to for all things ME7!
The DME consists of the EEPROM and flash memory. In order to write a different tune to the flash, you must first turn off the immobilizer in the EEPROM.
You'll need to make a bench wiring harness to power up the DME (see bottom photo in photo album).
You'll need a OBD2 to USB cable. I bought a generic one from eBay. Search for "FTDI FT232RL VAG COM KKL 409.1 OBD2 KWP2000 ISO9141 USB FOR VW/AUDI".
Step 1 - Reading the EEPROM:
- You'll need to download me7-eeprom-1.40.zip from Nefmoto (free account required). http://nefariousmotorsports.com/forum/index.php?topic=1168.0
- This is the command to read the EEPROM:
  - me7eeprom.exe --OBD -r -p 2 outputfilename.bin
Step 2 - Modifiying the EEPROM bin:
- You'll need eepromtool_04.exe. Windows Defender will flag it as a virus but it isn't. https://github.com/turboat/eepromtool/releases/
- This is the command to take the bin file produced above and turn off the immobilizer:
  - eepromtool_04.exe --in filename.bin --immo off --out newfilename.bin
Step 3 - Writing the EEPROM:
- You'll use me7eeprom.exe again.
- The DME will need to be in boot mode to write the bin file produced in step 2. This requires physically opening the DME and bridging 2 terminals while powering on the DME. Please see the first link in the "Threads of interest" section. Nefmoto has detailed instructions on finding the pins to bridge for boot mode. In my experience, bridging for exactly 2 seconds will allow boot mode. Any more and it freezes the DME. Freezing the DME isn't bad, it just means that you have to power off and retry the boot mode process. Once you get the timing down, you can reproduce boot mode fairly consistantly.
- This is the command to write the bin file to the EEPROM:
  - me7eeprom.exe --bootmode 95040 -wp2 immo-off-file.bin
Now you have a DME with which you can write custom flashes to. You will use the Nefmoto software to write any flashes. The software is downloadable via the first link in the "Threads of interest" section.
Vehicle Speed Sensor:
- You'll need an ECU bin file that's been modified to remove the need for a VSS input. This is important on all 40v ECU's, otherwise you'll be soft rev limited to 6k RPM.
- I modified an ECU bin file that I found on Nefariousmotorsports.com (http://nefariousmotorsports.com/forum/index.php?topic=4368.0 ), as well as a 559E XDF file. I used TunerPro to edit the bin file at address 16778. My bin had hex value of 5474, which converts to 5405 RPM. I replaced that hex value with 7080, which converts to 7200 RPM. You will need to run me7correction (including me7sum in the same folder) on the bin file to correct checksums before writing the file back to the ECU.

Boxster 986 DBW throttle pedal wiring to Audi DME

The following wiring connections work on ME7.1.1 ECU's. They may work on ME7.1 ECU's too but please do your research beforehand by checking out some wiring diagrams for the VAG ecu/engine combination you are using. See the "ME7.1/ME7.1.1 ECU Pinouts" link above in the Threads of Interest section, 6th link down.
Audi DME pin 72 to Boxster pedal pin 3
Audi DME pin 73 to Boxster pedal pin 4
Audi DME pin 33 to Boxster pedal pin 1
Audi DME pin 34 to Boxster pedal pin 6
Audi DME pin 35 to Boxster pedal pin 2
Audi DME pin 36 to Boxster pedal pin 5
***These pinouts are only for the 996/986 'round' style throttle pedal sensor. The 987 throttle pedal has the sensor built-in to the pedal assembly and appears to not output the same signals as the 996/986 sensor, at least in my testing.

Transmission Information

See also the "VW/Audi 012 Transmission Info" page link at the top of this page.
The Audi 1.8t/2.7t/3.0/4.2 all bolt to the 986/987 5 speed transmissions and the 987 6 speed transmission. The 986 6 speed has a different bell housing bolt pattern.
I'm using the stock Boxster 5 speed transmission and axles for now. I have a 987 6 speed on the shelf for a possible winter project.
I modified the stock 5 speed transmission mount brackets by cutting and re-welding them (see photos). This put the transmission approximately 2 inches lower.
The stock shifter cable bracket had to be modified a little since the engine and trans sit 2 inches lower than stock. This is done to because the cables are now at a steeper angle in regards to the stock location on the bracket.
The shifter cables run over the top of the engine. It is a little tight as far as the length of the stock cables. Mine are zip tied to the passenger fuel rail.
I'm using the following parts:
- TTV Racing single mass flywheel p/n 4646 - This is a 60-2 crank trigger setup. (http://ttvracing.com/product/audi-v8-4-2-8-bolt-to-o1eo1a-gearbox-2/?referrer=homepage&iframe=true&width=80%&height=100%&type=flywheels&engine=audi-v8&manufacturer=audi)
- Bosch 0261210190 crank position sensor with 2mm spacer (verified works on 5 speed 012 trans)
- Audi B7 RS4 stock clutch and pressure plate - LUK 02050
- ARP flywheel bolts 254-2901
- ARP pressure plate bolts 101-2201

Cooling System

I'm using the CSF 7044 radiators. I installed the center radiator for extra cooling capacity. I also upgraded the "Base" model coolant pipes to the "S" pipes, which I highly recommend for anyone considering a swap on a 2.7L manual car. The 2000-2004 2.7L Tiptronic cars all had the "S" size coolant pipes.
Stock Audi 82° thermostat was changed out for a 77° thermostat.
I used a Gates 25484 flexible radiator hose from the thermostat inlet to the stock passenger side Boxster hose that was cut in the middle. The two hoses are joined with a 1.5" hose coupler (https://www.amazon.com/gp/product/B07KQFWQXQ).
- As an alternate to the Gates hose, below are the Dayco options:
  - Dayco Flexible Radiator Hose 81351 - 1.5"x30"
  - Dayco Flexible Radiator Hose 81201 - 1.5"x25"
I modified the stock Audi V8 coolant pipe on the back of the heads. I relocated the coolant output pipe from the passenger side of the engine to the drivers side (LHD). I also added a 1/8 NPT fitting to the pipe in order to add a coolant temp sensor for a standalone gauge. I used 1.75" steel pipe to then run along the drivers side (LHD) of the engine to the coolant outlet at the rear of the cylinder head. UPDATE: I've discovered that the BGH engine code from the Phaeton puts the coolant output on the left (Drivers side in the US) of the car. Looks like there will be no modification required.
- I've modified this setup in order to clear the AC compressor. I used an ICT billet hose couplers 1.75" (https://www.amazon.com/gp/product/B084KXXXVR) and 2 Dayco flexible radiator hoses (p/n 81351 - 1.75"x23.5").
The stock Boxster DME is retained to operate the dash for the coolant temp and tachometer, and to operate the cooling fans and engine compartment fan. The only inputs to the DME are coolant temp, crank signal, and engine compartment temp.
Make sure you change the Audi oil cooler pipe! The stock coolant pipe from the engine to the oil cooler is plastic and very prone to breaking; Change it to aluminum. These can be easily found around the internet. I got mine from eBay.
I'm using an Auto Cool 85 PWM controller for the stock radiator fans. I permanently grounded the relay for the stage 2 cooling in the rear trunk, which is the stage where 12v is sent directly to the fans (not going through the resistor). I ran the grounds from the fans directly to the controller which then decides when to turn them on based on a coolant temp sensor attached to the return pipe right out of the radiator on the passenger side (LHD).

Fuel System

The stock Boxster fuel system is retained but since it is returnless (2002 and onwards), I used a returnless fuel rail from an Audi D3 A8 4.2L and flipped its orientation on the intake manifold. This required a little massaging of the fuel rail inlet since the manifold is not exactly symmetrical.
The fuel tank purge line will be plumbed near the air filter but will only have a filter to prevent debris from entering the pipe.

Exhaust System

I'm using the factory S8 manifolds (I believe they are the same as any other 40v manifolds). The factory Audi exhaust are very nice pieces!
The Audi manifold flange is 2.5", however from the factory, Audi uses a 2.25" pipe welded inside this flange. You can cut the weld and use 2.5" pipe for your exhaust.
My exhaust system is completely custom. I'm using 2.5" mild steel tube. Since this will be a track car, I'm using no catalytic converters and no rear oxygen sensors.
I used a Speedway Motors 2.5" custom exhaust pipe kit and 2 Thrush 17715 Turbo Mufflers. The entire system is sprayed with Design engineering 010302 high temp silicone spray and then wrapped with Design Engineering 010130 Titanium wrap using stainless steel ties.
Since the exhaust system is relatively close to the stock 5 speed clutch slave cylinder and lines, the lines are all covered in protective Design Engineering 010652 wire cover heat shield.

Suspension/Subframe

I'm using Godspeed MAXX coilovers that I purchased from eBay.
I had to modify the stock rear suspension crossmember since the engine/trans assembly is a couple inches lower (see photos).
I also had to make a bracket to shift the sway bar down a little to clear the lower transmission.

Files

This section is for STL/STEP/DXF files that I've made or others have provided to further the development of these engines and swaps. It's all a work in progress. If you have ideas for parts to model, let me know. I've also included some very good PDF's. If you'd like to contribute to this section, that'd be rad!

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