Any progress on V8 engine swap options?

[titaniumdave]

Here is a pic of the whole thing ready to get stuffed in the car. Note the V bands on the stock headers to direct exhaust away from the motor/CV's and clutch slave. I'll be making an exhaust that will be 3 sections, 2 side connector pipes and a single muffler section. There will be a total of 4 V bands which will make things easier to live with(I'm hoping...) since I should be able to not support the connector tubes so a motor drop will be faster at the track. Motors are so cheap my plan is to have a spare on a cradle we take to the races...

[titaniumdave]

Here are pics of the longer pins I made to work with the 11mm spacer, and the cut I made to clear the starter bolt. Pins have a step machined on them so they help align the spacer and stay aligned/perpendicular with the motor mate surface.

[titaniumdave]

Originally Posted by Realtormike

I am down for a cradle mount.

If you want one, looking like the cost will be about $1200. I am only going to make ones to cover paid orders.

Steel prices are going through the roof now so there may be an extra $300 to cover tariffs but I will know when I order the parts. I have seen a +50% increase in my steel prices since the first of the year...same US made product I have been buying for years.

[titaniumdave]

Here is a mod I made to the Audi alternator plastic, as I lowered the motor in the cradle to get clearance for the heads the plastic schnozzle on the bottom of the alternator came in contact with the cradle. I cut an inch or so off the bottom of it with a cut-off wheel...I don't know what the cover does but having it shorter seems like the correct choice.

[Escy]

For those of you ordering cradles, i'd hang on and see how this build pans out. I've seen plenty of Audi V8 builds that end up being a dogs dinner when it comes to finishing them off. Roofs that won't fold, loads of metal hacked out, etc. Most seem to bolt the engine to the transmission, leave the transmission in its original place and then have to hack away to make it fit.

[titaniumdave]

Originally Posted by Escy

For those of you ordering cradles, i'd hang on and see how this build pans out. I've seen plenty of Audi V8 builds that end up being a dogs dinner when it comes to finishing them off. Roofs that won't fold, loads of metal hacked out, etc. Most seem to bolt the engine to the transmission, leave the transmission in its original place and then have to hack away to make it fit.

As stated before, this is a RACE CAR build. I will 'hack loads of metal out', there will be NO folding top, there will be NO trunk, it's a race car, all that stuff is un-needed weight. Happy to make a dog's dinner if it's a fast dog's dinner!

Don't buy one if you don't want one.

The second cradle we are working on will be one that will work with V6 and V8 Audi motors using the Audi motor mounts rather than the Boxster front mount. More designed for a street application. The problem with the V8 installation is how to make the throttle body fit under the folding top compartment, this cradle drops the motor about 40 mm, there is more room to go down but it creates other clearance issues so I'm not sure how folks want to deal with those. We are looking at ways to point the TB down and out to get some clearance, I am a bit worried if I move the TB too far from the plenum it will create other problems. Input would be appreciated on this aspect.

[Escy]

I'm not slagging off what you've done, just a word of caution to people wanting an engine mount to wait and see how it pans out. Seems a bit premature to sell the cradle before you've finished the build and tested it.

For example, I know the Renegade V8 swaps use the original gearbox mounts and use engine mounts at the side and the whole lot pitches up at the front under load.

[B6T]

There's a reason why Audi puts the snub mounts on the front of their engines...

[titaniumdave]

Originally Posted by B6T

There's a reason why Audi puts the snub mounts on the front of their engines...

That is why my cradle attaches at the snubber mount as well as the side motor mount locations.

[1thenaton1]

Thanks for posting your progress, I am interested in this swap for my track car

[B6T]

Originally Posted by titaniumdave

That is why my cradle attaches at the snubber mount as well as the side motor mount locations.

Yep. My response was directed at Ecsy and his mention of the engine pitching up under load.

[1thenaton1]

bump, any updates Dave?

What engine code Audi V8 did you use, and what are you doing for wiring/ECU? Looking to move forward with this swap this winter

[specboxCO]

I used a 40v A8 AUX engine in mine. Biggest decision between the 40v and 32v engine is whether to go drive by wire or cable throttle. There is a slight mod to the accelerator pedal wiring in the Boxster needed if you run DBW.

I used the stock Audi 7.1.1 ECU from the A8 adapted to the Boxster harness. ECU had to be hacked to remove the immobilizer and then flashed with a Euro S6 manual tune and finally modded to remove the rev limit for the missing vehicle speed sensor signal.

The temp gauge doesn't work and the fuel gauge light is permanently on, but the tacho and speedo both work fine.

Radiator fans don't work if you use the Audi ECU, but I switched from the stock water pump to an external electric Davies Craig pump and temperature controller which can drive the fans.

[specboxCO]

Originally Posted by titaniumdave

That is why my cradle attaches at the snubber mount as well as the side motor mount locations.

Just an FYI, your tensioner is on the wrong side of the belt in this photo. You should change the routing to come from the fan pulley to the crank pulley, then over the tensioner to the alternator. I used a tensioner from a Touareg as its a little shorter to provide some additional clearance.

[78F350]

I feel bad about not having mine done yet. A week ago, I finished up some work on the '04 and pushed my swap car into the garage. I got about 10 wires spliced (crimped) before getting myself all wrapped up in the crimp vs solder debate. Outside the engine compartment, I've decided to go with solder now.

And before I got back to it, I bought an '81 Scirocco from a junk yard, so now my attention is a little divided again.

I have the same engine and ECU as SpecboxCo. All the stuff that he said about the wiring concurs with what I have found. I think we can find work arounds for most of it, like a temp switch wired to the Boxster's fan relay line ( it looks like the 7.1.1 runs a similar line to the HVAC module). same thing for the low fuel light; If the Audi ECU doesn't have it, find a spot to tap the signal you want and wire it in.

Of course, what model year you are swapping into will make a difference. I haven't looked at the 5.2 DMEs, but I think the 32 valve is the way to go with those. XR_Guys posted a nice spreadsheet in this thread if you are looking for the DME 7.2 pin assignments: https://www.renntech.org/forums/topic/51783-boxster-dme-72-to-78-transplant/ There's already a good DME 7.8 .PDF floating around the net.

[Escy]

Originally Posted by 78F350

I think we can find work arounds for most of it, like a temp switch wired to the Boxster's fan relay line ( it looks like the 7.1.1 runs a similar line to the HVAC module). same thing for the low fuel light; If the Audi ECU doesn't have it, find a spot to tap the signal you want and wire it in.

The fans on a Boxster are triggered by the ECU grounding the trigger wires. You'll likely need a fan controller to do that. Simple and cheap enough.

On the later canbus Boxsters, I believe the last 1/4 of the tank is calculated by the ECU so the level just drops to zero. The low fuel light, engine temp warning light, engine temp gauge and check engine light are all on the canbus.

[78F350]

Originally Posted by Escy

The fans on a Boxster are triggered by the ECU grounding the trigger wires. You'll likely need a fan controller to do that. Simple and cheap enough.

On the later canbus Boxsters, I believe the last 1/4 of the tank is calculated by the ECU so the level just drops to zero. The low fuel light, engine temp warning light, engine temp gauge and check engine light are all on the canbus.

You have a running, swapped car and I have a partially connected mess of wires. I trust you. Initially I plan to have a pair of simple switches on the dash for fan-low and fan-high (okay... probably one three position switch).

The fans on the Audi A8 are triggered by the HVAC Control grounding the trigger wires (through D7, Brn/Yel). [and there is also a thermal switch on the lower right side of the radiator and the AC pressure switch for fan speed, but lets keep it simple for now.] The HVAC Control has two connections to the ECU pins 40 and 41 on the 7.1.1 and pins C11 and C14 on the 7.1 (Green/Red and Red/Black wires on both). I don't have all my reference material handy, but I expect that they are AC demand to the ECU and a cooling fan demand to the HVAC.

I haven't looked at the details of the fuel warning yet, but I expect that it will be easy to make the light not be lit.

[B6T]

My understanding of the fan switch from the S4/A6 which is mounted in the lower part of the rad hose is that once it reaches a certain temperature, it closes a circuit, for two different circuits and at two different temperatures. Has anyone considered using that simply to trigger the fan relays, which the Boxster ECU normally does?

Otherwise, this guy makes some nice fan controllers that look like they will work nicely with the Boxster:
WWW.AUTOCOOLGUY.COM | CONTROLLERS

Originally Posted by specboxCO

I used the stock Audi 7.1.1 ECU from the A8 adapted to the Boxster harness. ECU had to be hacked to remove the immobilizer and then flashed with a Euro S6 manual tune and finally modded to remove the rev limit for the missing vehicle speed sensor signal.

Mind sharing the file?

Originally Posted by Escy

On the later canbus Boxsters, I believe the last 1/4 of the tank is calculated by the ECU so the level just drops to zero. The low fuel light, engine temp warning light, engine temp gauge and check engine light are all on the canbus.

I'm going to be doing some canbus sniffing in about a week or so. Might be able to get this stuff working properly with a arduino board. A local friend had to do this with his RX8/LS swap.

I'm also debating going with an EMU Black stand-alone instead of the factory Motronic. That's a pretty sweet ECU.

[Escy]

I'll be interested in seeing what you come up with if you go the arduino route. I've found some canbus info.

Megasquirt Support Forum (MSEXTRA) • CANbus to Instruments etc. working (View topic)

[78F350]

I was looking at some unrelated stuff online and came across this car:


I remember Rob Scott posted here a few years ago about doing a 2.7L biturbo swap for a Rallycross car.
Rallycross Porsche Boxster

He didn't really track his progress here on the forum, but it looks like it came out well.

https://www.facebook.com/AngrySpiderRacing
https://www.engineswapdepot.com/?p=11070

Highly modified and very innovative.