Damn cool man!

I'm curious though about the scoop. Is there not enough positive air pressure at the rear deck lid for a scoop there? It would be 100x cooler without the scoop. What about side scoops of some sort through the fenders ala Countach?

Nice update. I haven't checked in for a while and you have come a long way with the car. It is truly a work of art with great attention to detail. Bravo!

I found your dyno chart interesting as well. That nearly vertical torque curve from 3.5k-4.3K must feel like getting hit with a hammer. :D If you bring the car back to Fontana for the Festival of Speed in April, as a very experienced Boxster driver on the Roval I would be willing to offer my services and act as test pilot for a few sessions... Purely in the interest of gathering data of course. :D

The next step on that front is to install some temp probes before and after the intercooler and log the air charge temps under different conditions and set-ups.

The side ducts are being used for oil coolers for the engine and trans.

Yeah the power delivery is completely different than the M96. In the CalSpeed video, I was experimenting with leaving the car in third gear rather than dropping down to second to see what different RMP/boost levels would do. In second gear, the car would spool instantly with any throttle input and the back end would try to come around. In third, it I would get some turbo lag but it kept the car from lighting the tires up on corner exit.

No PCA events planned right now. We are doing the NASA event at Buttonwillow April 21-22.

i wonder if anyone has ever tied an electronic boost controller into a steering wheel position sensor - less boost when turning, more boost in the straights ...

That is a very busy weekend. PCA at Fontana, POC at WSIR, and NASA at BW. It's a shame these guys couldn't coordinate their event schedules better this year. Personally I think BW and Chuckwalla are better Test-N-Tune tracks when you have unknowns to uncover. I don't really like surprises at 135 mph in turn 2 at Fontana... spook city!

Keep working out those little details with the car. I think you have a winner once everything is sorted.

But what happens if you happen to have the wheel in a neutral position in the middle of a turn/slide (not likely, but could happen)? Full boost when you don't necessarily want it. Or on the flip-side, your boost gets cut when you cut the wheel to move from behind someone to make a pass.

I definitely get where you're going with the idea and see potential with it, but that was where I could see trouble with such a thing.

ok, how about interfacing it with a lateral-g sensor? reduced boost when the car is pushing sideways ...

I don't know. This might result in the same thing as a "lift throttle" mid corner, inducing a spin. The basic rule with a 930 or 951 is: When the car comes on boost, make sure your steering wheel is pointed straight... even if you are mid-corner make sure the wheel is pointed straight.

If it was my car being built, I would favor a wider, fatter powerband and give up some top end HP in favor of drivability. A 997TT is really pretty good here and any turbo motor could be tuned for drivability. Everything is a tradeoff.

I am seriously toying with the idea of building a turbo capable Subaru EG33 (3.3 liter flat six cylinder) and swap it in using the same turbo as what's in there now. More torque, more linear power, and faster spool. The down side is the engine is heavier and longer and parts aren't as readily available.

Nah! Get this one sorted and see where she is. Every car has it's own personality and you just have to adapt your driving style to the car. With my car and a stock 2.5L I have to maintain corner momentum and get on the gas really early on corner exit or I am dead meat. With the Boxsubi, you can drive it more like a Viper... Easy into the corner, get the rear really settled on exit and then hit the hammer. You can afford to wait on the throttle a bit because there is so much juice available.

I gotta be honest. When I saw you were putting a STI motor in there I had visions of wiring harnesses hanging everywhere with splices and electrical tape, and two shift levers sticking out of the dash. :eek: So many projects like this end up as science experiments gone bad. I am totally impressed though. I had a hint you would put it together well because I had seen some of your Boxster Spec exhaust fabrication and I knew you were pretty handy with a TIG. Stay the course. This car will turn out great.

Any update on how this project is going? I'm glad to see someone tackling it properly.


I'm pretty excited about the prospects of your street version but am curious how you envision the electrical integration on a street vehicle. I can see stand alone engine management but am wondering if the CAN bus system for the rest of the car will freak out with the engine missing.

Yep. My 2011 Mazdaspeed 3 has that and I have to say it is pretty annoying and wish I could disable it for track days (technically you can but it also disables the electric steering assist).

Quick update...

Based on the over cooling we experienced during testing, we decided to try out a new intercooler set-up. Without adding any serious complexity, or reconfiguring the front of the car, we were able to add an air to water intercooler system and get rid of the roof scoop. We will be utilizing the center radiator from the engine cooling system as a heat exchanger rather than using it for engine cooling, then just replace the air to air intercooler with a new intercooler, plumb a few water lines and add an electric pump. Basically the same components we will be using in the street cars, but with a slightly larger intercooler core. We will be testing the new set-up this weekend, but already, the benefits are a reduction in weight (up high and out back), reduction in aerodynamic drag, lower center of gravity, and better rearward visibility. We just got back from some dyno tuning and the car made 430whp and 380ft/lbs. The car now weighs 2651lbs with a half tank of fuel and an empty cool shirt cooler. There's another 20lbs that will be coming out over the coming weeks. Leakdown numbers are still right around 10% (cold) which is what they've been since the first test day.

http://i180.photobucket.com/albums/x...9207515875.jpg

Awesome!! Please keep updating this thread!

Well I've decided to change things up a bit. The Subaru conversion has proven to be 100% reliable in race application, so this prototype drivetrain is going to be transplanted into a street car for further testing in a more practical application. The street car will have A/C, non-electric power steering, and all of the creature compforts of a daily driver.

The race car on the other hand... it will still get an engine conversion, but something a little different. I'm actually going to pull back on the horsepower a bit and drop down a class to mix it up with some new cars. I'm going for linear power and hopefully keep the weight the same, if not slightly less. We'll see...

http://i180.photobucket.com/albums/x...psaed9dc92.jpg
http://i180.photobucket.com/albums/x...psc7cc7146.jpg
http://i180.photobucket.com/albums/x...ps5f7eef9f.jpg

Yes, I realize that this has been done before, but this one will be a little different.

Sweet; can't wait to see the build

more, more, more! AUDI V8 - no waiting YIPPEE!!! Looks like a PORSCHE 5-speed? What MY is the V8? Is the tubular structure an engine cradle?

Yes, the tubular structure is the engine cradle. The transaxle is a 5 speed. The engines are only rated at around 300hp so there's no need for the extra 30-35 pounds of the 6 speed transaxle. Obviously the 5 speed bolts right on, but before you get too excited, as of right now, I don't have any plans of making a "kit" for this application. I'm not sure you will find very many people who would actually be interested in such a kit once faced with dollar figures. Horsepower for dollar, the Audi V8 is not the best option in my opinion. I can go into more detail about this if you'd like, but I'd rather start a new thread on this conversion and go into it there. The engine is the ABZ 4.2 which you can find in the 1997-1999 Audi A8. The engines are silly cheap, but the engine blocks are an "Alusil" design so most people view them as disposable and there is very little aftermarket support for them. For my application specifically though (I'm searching for a horsepower to weight ratio of no better than 8:1) it's perfect.

would you start a new thread about the best V8 options for the Boxster? I would really appreciate your input KCPAZ.

Always contemplated an Audi V8 swap in the Boxster. Subscribed!

I'll start a new thread with some more pictures and info in the next few days.

cool. with the Porsche/audi 5-speed are you using the oem transmission mounts - ie, does the engine fit far enough forward? any other fit issues?

Yes, the engine cradle was built around using the OEM style transaxle mounts to position the engine in the engine bay, and it fits... barely. For me, it was important that none of the engine's oil pan would hang down below the level of the floor pan so I probably raised the engine up higher than the others who have done this in the past. As a result, the cam position sensor is extremely close to the top of the engine bay, and one of the breather lines coming off of the driver's side valve cover will need to be relocated so I can use an unmodified engine lid. This package will be using solid engine and transaxle mounts so I'm not worried about the engine torquing under load, but if it weren't for that, something would have to be done to either space the whole drivetrain down to prevent the engine from hitting other things. These are all relatively small issues though. The biggest problem is going to be the intake manifold and throttle body. I'll go into that in more detail later.

perhaps check into a cayman/987 engine lid - apparently same mounting points as a 986 but more room to clear the taller m97 intake manifolds.

To be honest I think everyone on here has petrol in their vanes so of course we would be interested. Personally i see this route as a good was of saving some of the early 2.5 cars where the replacement engine costs mean the car would more likely be scrapped upon serious engine failure.

Show us the way….and watch us beat a path to your door!

Good stuff!

Awesome welds BTW. Never seen anything that precise outside of aviation.

You do really good work, but can I'm asking, "Can I afford it?" I know you said you were not ready to sell the Audi V-8 as a kit vs. the Subie kit (from your race car)….BUT can you HELP those of us who have blown Porsche engines? Seems a shame to scrap a perfect car, aside from the engine.

There HAS to be a less expensive alternative than spending $10-12 grand for a Chevy LS/LT conversion by Renegade or a Raby rebuild - so us "regular guys" can afford it.

Has anyone seen a Honda engine in a Boxster? There are tuners for those engines pushing 800HP for less than $10k. Was looking to spend around $6k myself. Could sell my engine (and a kidney) on ebay for a couple grand and only be out labor and $4k or so.

Would you be able sell the "old" Subie as a kit kcpaz?

The truth about QUALITY engine conversions is that no matter what engine you use (Subaru, LSx, or Audi V8) it's not going to be cheap. Just yesterday I was going through some of the invoices from customers in the past where we did engine conversions for. I just don't see how you could do a conversion for less than $10-$12 in parts, and that's not including the cost of the engine. There is just too many details that need to be factored in that most people don't even think about. Simply mounting the engine and transaxle in the chassis is the easy part. There are so many other systems that need to be integrated and need to be modified to work properly. It's not like the old days of small block Chevy's where all you had to do is bolt the engine in, run a fuel line to a carb, hook up an ignition box and a throttle cable and go on your way. There is a lot more to it than that. Here's just a quick run-down of things that you would need to address in a Subaru conversion...

- Subaru turbo engine
- Engine adapter kit
- Clutch
- Engine cradle
- Motor mounts
- Headers
- Post-turbo exhaust system
- Complete engine management system for Subaru sie of things
- Turbo scavange pump
- Complete intercooler system (air-to-water system means adding a third radiator up front on the non-S cars)
- Speed sensor kit for Subaru ECU (bolts to CV joint)
- Plumbing for fuel system
- Plumbing lines (hard lines) for coolant line adaptation to chassis
- RPM signal modifier for tachometer
- DBW throttle pedal kit (if Subaru engine is drive-by-wire
- Turbo charger (the Subaru turbo won't work in the Boxster chassis very well at all
- Plumbing for the turbo charger
- Custom A/C compressor lines
- Custom power steering lines
- Modified brake booster reference line

These are just the items I can think of off the top of my head.

The point is, it's not as simple as most people think. Having said that, I still think that the conversion is worth it to the right person, in the right circumstance. If you are someone who is in love with the Boxster chassis (and I think that most people on this forum are), and you are interested in owning your car for a decent period of time (longer than a year), then I think in the long run, the conversion makes sense, especially if you find yourself in the position of owning a car that blew it's engine. If you're a Boxster owner who is looking to make more than 300HP at the rear wheels, and also meet the criteria above, then I think you may be a good canidate for an engine conversion. If you purchase a car with a blown engine solely for the purpose of doing an engine conversion, then I think you are the right person for this sort of conversion.

On the flip side, if you aren't willing to spend at least $12K in parts to improve whatever it is that you don't like about your current Boxster, and your car runs and drives perfectly fine, then an engine conversion is not for you. If you're a "tinkerer" who thinks that an engine conversion sounds like a fun weekend project, then an engine conversion is probably not right for you.

Personally, I LOVE the Boxster chassis, and they are a blast to drive. I don't however, have any love whatsoever for the M96 engine. I think the Boxsters could have become greater than they were had they not been cursed with such a problematic engine. An engine, that never really made impressive horsepower on top of all of it's other flaws. Once the early cars started becoming available for around $3000 with blown engines, I knew the time was right to start developing an alternative to simply scrapping the cars out, or spending way too much to replace the blown engine. The cars are too good to simply write them off as a loss because the engine are an issue.

To answer your other question... Yes, I do have Subaru engine conversion kits available for sale. you can email me at precisionchassis@gmail.com for more information

Please someone ban kcpaz for posting all this car porn! I would love to have the Audi v8 in my Boxster. Jk don't ban him.

I love the 914 conversion. Out of curosity, how pennies would one have to save for that. I had a '75 914 that I wish I kept and converted (the guy who bought it from me turned it into an electric car).

The cost to convert a 914 or a Boxster is basically the same. If anything, the 914 has the potential to be more expensive because you have to add a radiator system that never existed, not to mention the inevitable rust issues associated with almost every 914 in existence. We are currently finishing up putting a Subaru 3.3 H6 engine in a 914 using a Boxster 5 speed transaxle. Should be a pretty awesome car when finished.

Quick update on the V8 conversion. Next step is engine management wiring...

http://i180.photobucket.com/albums/x...ps512db88e.jpg
http://i180.photobucket.com/albums/x...ps2153904c.jpg
http://i180.photobucket.com/albums/x...ps63a6ae77.jpg
http://i180.photobucket.com/albums/x...ps3a5b6b32.jpg
http://i180.photobucket.com/albums/x...ps7a381842.jpg
http://i180.photobucket.com/albums/x...psc21d19d6.jpg
http://i180.photobucket.com/albums/x...ps8a9bbfac.jpg
http://i180.photobucket.com/albums/x...psaf2627d0.jpg
http://i180.photobucket.com/albums/x...ps8a73e1b2.jpg

you guys really do some amazing work

Nice, the exhaust may be a touch loud ! :eek:

Yes... VERY loud ;)

Obscene pictures
 

BTW, The welds on the intake plenum are awesome...!
Is that an Audi V8 engine?

.

Yes, its an Audi ABZ engine.

Very Nice!

Awesome! Any news on this project?