Any progress on V8 engine swap options? - Page 8 - 986 Forum - The Community for Porsche Boxster & Cayman Owners

stuklr · 06-05-2018, 10:32 AM

My 2001 Box S with an Audi 4.2 40V AUX V8 is also on the road. Running on the Audi ecu and my own custom coding. Just charged the AC today.

specboxCO · 06-08-2018, 02:05 PM

Quote:

Originally Posted by B6T

Did changing that value in the ECU program solve the VSS issue? Did you eliminate the cluster from the trunk?

Yes. Managed to up the rev limit in the ECU for the No VSS issue. Runs perfectly now.

specboxCO · 06-08-2018, 02:07 PM

Quote:

Originally Posted by stuklr

My 2001 Box S with an Audi 4.2 40V AUX V8 is also on the road. Running on the Audi ecu and my own custom coding. Just charged the AC today.

Did you manage to keep the top operational? my engine takes up all the space the top occupied. how did you route the air intake? Pics?

stuklr · 06-08-2018, 03:03 PM

Top is totally unmodified. Air intake passes into rear trunk through original wire harness hole. New engine harness enters rear trunk via old coolant bottle piping hole.

How high did you mount your engine? I clocked my throttle body with a spacer I made and the top bow lays down just like stock. Engine cover is raised two inches in the front, then tapers to the OEM location in the rear.

I don’t have pictures hosted anywhere. These old forum formats are terrible.

stuklr · 06-08-2018, 03:12 PM

Btw, if you need any software help, i have done alot with the 40V V8 and tuning in the audi chassis. Still making it 100% in my boxster. I’m using an AUX engine code A8 engine.

specboxCO · 06-09-2018, 06:16 PM

Quote:

Originally Posted by stuklr

Btw, if you need any software help, i have done alot with the 40V V8 and tuning in the audi chassis. Still making it 100% in my boxster. I’m using an AUX engine code A8 engine.

That is the exact engine I'm using. Ive done a bit of messing with the ecu software. Mainly just raising rev limits. What have you done to the tune?

Are you using the euro S6 manual as a base and modding from there? Did you also use the S6 intake.

stuklr · 06-09-2018, 08:35 PM

Yes started with the euro S6 file. Modified to control the oem A8 intake flaps and deleted all the unnecessary emissions and additional parts. I am going to stick it on my dyno this week and see if the oem intake flap changeover points are still good since the intake and exhaust is much different. The i alsohave further work to do on timing and throttle mapping. It’s too touchy at low rpm. I’m running a fidanza light weight flywheel and a lower torque request at sub 2k will make starting off gently easier.

stuklr · 06-15-2018, 06:59 AM

http://12v.org/urs/4.2 V8 vs 3.2 F6 tuned.jpg

Stuck my 2001 Boxster S with an Audi D2 A8 4.2 AUX engine on my dynojet today. New V8 puts the previous flat 6 to shame!! Nearly 90 more lb/ft of torque at 3500 rpm. Still revs out to 7200 like the 6 did, but with more urgency. Still has the same charm of the rev happy boxster.

The 4.2 is not internally modified and is breathing through an OEM boxster S muffler.

The old 3.2 S flat 6 had my tune, headers, no cats, open mufflers and an afe cold air intake.

Both on 93 with similar ambient temps.

78F350 · 06-15-2018, 07:37 AM

Quote:

Originally Posted by stuklr

http://12v.org/urs/4.2 V8 vs 3.2 F6 tuned.jpg

...

Just curious, is 12v.org your site? I've had a '98 Quattro Avant for about a year and really appreciated the info available there.

Seeing the new action in this thread is getting me motivated to get back to work on my AUX swap. It has been sitting waiting for me to mate the harnesses together for months while I focused on my '04 SE flood car project. Now I want to hear that V8 roar with life.

stuklr · 06-15-2018, 10:22 AM

Nope, a friend of mine owns it. I just use the pic repository there.

Get that car done! I can help with the ecu setup if you need. I have the tune perfect for the boxster chassis.

itsnotanova · 06-18-2018, 12:50 AM

Quote:

Originally Posted by specboxCO

This thread has gone a bit quiet lately, so I thought I would post something motivational.

I have completed my V8 swap and got it to the track for its first test.

https://youtu.be/7ecn5ByaAtM

Might not look like much, but its been 2 years in the building. Runs a 40v 2002 Audi 4.2 using an Audi ecu, Cayman 5 speed transmission (may swap to a 6 speed now I have the VSS problem sorted) volvo electric power steering, BMW ABS system.

Will be racing it in 2 weeks at High Plains Raceway in Denver in the World Racing League endurance series.

Gavin, How did it perform on the track? I saw video of the start and it looked like you were in GP0.

specboxCO · 06-18-2018, 02:24 PM

Performed great for around 5 hours, then a weird fueling issue took us out of the race. Car would idle fine, but would get around 2 laps, cough and die, unable to restart for 10 minutes, then fine again. Thinking some kind of vapor lock issue in the system

Will be going over datalogs this week to try and understand what happened.

itsnotanova · 06-18-2018, 08:45 PM

I have a friend that races in autocross and had that problem twice. One was the fuel pump getting too hot and he noticed it happening more as the fuel level went down. It was a return fuel system. Cold fuel going out and hotter fuel coming back. The second time he had a similar issue was when he had the DME mounted right above the exhaust on the trunk floor. The exhaust heat was overheating the DME.

B6T · 06-26-2018, 09:49 AM

Quote:

Originally Posted by stuklr

Yes started with the euro S6 file. Modified to control the oem A8 intake flaps and deleted all the unnecessary emissions and additional parts. I am going to stick it on my dyno this week and see if the oem intake flap changeover points are still good since the intake and exhaust is much different. The i alsohave further work to do on timing and throttle mapping. It’s too touchy at low rpm. I’m running a fidanza light weight flywheel and a lower torque request at sub 2k will make starting off gently easier.

To what degree does the CAN on your engine and the CAN in your Boxster communicate? As mentioned the coolant sensor is a known CAN thingy, as is the speed sensor although we've seem to come up with a work-around. In my readings I understand that it may be possible to re-address some of the messages using the same tools used for Motronic tuning. So I'm wondering if you were able to do that.

The CAN stuff is something I'm not sure I want to deal with. I'm most likely going to sell my '03 S and buy a '97 Base for the swap to avoid all the emissions problems that I think could surface as a result of CAN mismatches. One thing in particular that I'm worried about is if the emissions readiness monitors are speed/distance dependent and then therefore, something that will prevent my car from passing the OBD smog test. Pre-99 cars in my area are permitted a tail-pipe test, which means I'll just throw a standalone EMS on it and be done with the whole thing.

Thoughts?

78F350 · 07-20-2018, 07:34 AM

Quote:

Originally Posted by titaniumdave

Big thumbs up on the sound of the V8! We are working on a universal cradle that will work with either V8 or V6 motor. Very close to having our V8 transmission, motor, clutch ready for the install. I have been doing due-diligence on the motor and the integrals are in much better shape than I was expecting so I'm calling that a win.

Dave, do you have a final product yet? I'm looking at the end of August for a good block of time to get my project going again. I'm pretty sure I'd rather use your cradle than the current chunk of iron I bought.

titaniumdave · 07-20-2018, 07:51 AM

Quote:

Originally Posted by 78F350

Dave, do you have a final product yet? I'm looking at the end of August for a good block of time to get my project going again. I'm pretty sure I'd rather use your cradle than the current chunk of iron I bought.

At this time I have the V8 only cradle proofed well enough I can make a copy for you. I have not had time to work on the universal V6/V8 cradle...too many projects and spinning my Elise into the wall last spring did not free up any time. I went with thinning the flywheel, dropping a couple of LB. off it and using a longer spacer to get my clutch spacing correct. I will have that bolted up this weekend which means the motor/transmission/mounts set is done for the race car! I am going to cut the stock exhaust headers' flanges off and weld V band flanges on them so that part will be done when the motor gets put in the car, hopefully the motor won't need to come back out till we blow it us! Plan is to run the exhaust outward and high to keep the run away from the clutch slave cylinder.

uniWerks Design · 07-26-2018, 04:03 PM

If anyone needs design/drafting help/support, message me. I'm a Certified SolidWorks Professional. Love to get this stuff designed right and documented for the community. :-)

Realtormike · 07-27-2018, 04:09 AM

I am down for a cradle mount.

78F350 · 07-27-2018, 07:19 AM

Quote:

Originally Posted by titaniumdave

At this time I have the V8 only cradle proofed well enough I can make a copy for you. ...

Did you get the PM I sent last week? I'm in and I'd like to proceed when your time is available.

titaniumdave · 07-27-2018, 11:44 AM

Hey guys, I just responded to PM. I will get some pics up soon of the progress, just V banded the stock headers to start the exhaust run for the new install. I'm going to route away from the motor/transmission to help with heat soak issues folks are talking about. With a race car I can cut away everything in the way and make plenty of room since the trunk is getting gutted.