Right now this car is a running 1972 914 with a 901 trans converted side shift, and a 350 SBC V8.


Salvage title car, registered etc. Calif.
BMW 320 calipers up front. Renegade conversion.

So there are many engines that work good in a 914.

The stock 914 4 cyl is about 180 pounds. (I am not sure if that is bare long block or dressed motor complete.)

The iron V8 with iron heads is about 525 pounds complete.

I have a motor that is a 4 cyl. that is 225 pounds long block and about 330 pounds dressed with a turbo.

It can put out 300-500 hp with equally high torque.
I have a 6 spd transaxle that adds a bit of weight but is far better.

So why is this 1.8 liter engine so much stronger than the original Porsche 914 1.8 liter engine?

The picture on the top is the naturally aspirated 914 head, the picture below that is the new engine's with a turbo force fed head. Yamaha was in on the creation of this head.

"An engine's power is limited by how much air can flow in and out of it."
Roughly quoted from some smart guy.

This engine has more valves than the Chevy V8.

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The engine I am talking about is one that almost everyone I have talked to knows nothing or little about :-)

It is an Audi 1.8 liter turbo 5 valve per cyl engine.

I have a 1999 Audi 1.8t 20v engine.
a Boxster S 6 speed trans.
an Audi 01X 6 speed trans.


The car wont be all Porsche but Porsche and Audi are closely related. The engine bolts to the trans. The engine is good if you do research to find out about it.

Here is the car.

I went and bought it. I got it for less than 6K. It has a posi or limited slip.

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I have an Odyssey PC680 Battery now.




.

Looks like fun!

I did the exact same thing. You can see it all in my build thread below.

Looking forward to seeing progress. Myself and Mike Bellis both have this swap running.


Where in California are you?

Near Bakersfield.
I have seen the fun you and Mike have been having here.



Pictures:

ok here is the 1.8t 20V engine.

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The audi trans has that same mounting flange geometry. Kind of squiggly looking.

The stronger Porsche transaxle I would prefer to use has a real round looking bellhousing.

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So they don't match but someone put an Audi V6 on this type of a Boxster trans.

See the shim on this bellhousing?


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So I need suggestions.
Can the 1.8T 20V adapt to this Boxster trans?

Could it be done with an adapter plate but not using a custom flywheel, clutch ...

Just make a thin (1/8" or 1/4" or 3/8") adapter plate?



Or forget this combination?

The boxster trans will bolt up. Mike has used both 5 and 6 speed units in his car.

The shim you see is something on the Audi v6s, not on the 4cyls. I can't remember why they use it but it's not a concern for the 4s. Just bolt it up and you'll see.

I have some washers on my 5 speed trans just to line it up perfectly by the oil pan. Not really a big deal.

OK I will use the 1.8t 20v and the Boxster S 6 spd.

I need to figure out the axles. Mike said 19.5" and 20.5" long in his thread. I nee to double check with this transaxle.

Hi,

I would be interested in buying some or possibly all of your v8 drivetrain if you want to sell. I’ll send a pm with my contact info.

Pierre

Thank you for your interest.

I might have it all up for sale after the swap is done. I am going to build the new power train fully before I pull any of the running gear it has. You have first shot at buying it. I hope it wont take a year but it might.

I measured the bolt hole circle diameter of the output flanges on the Boxster transaxle I have and I get 95mm.

You need to measure from the inside lip, aka the total diameter of the CV joint.

I will check it. Thanks for the help Sir.

Looks like the early 911 108mm CV.

Eng. and trans.Click to view attachment Click to view attachmentClick to view attachmentClick to view attachment

What I have:

Car
Water cooling in place
Engine
Transaxle
Shifter
Cables
Cable mounting bits on transaxle

What I don't have yet:

Fuel pump
ECU
Axles
Front motor mount
Rear transaxle mount
Exhaust
Intercooler
GT28 turbo
Chip
Injectors
Hyd. Clutch pedal
(not doing FBW throttle)

Goal 280 HP running car.
20 lbs boost at max.
Not changing dash or steering wheel.

Fuel pump: I recommend a bosch 044 in a surge tank. I put mine in front of the motor. Way more fuel than you need. You can run a cheep chineese version with that much power and not have to worry about maxing out the pump. Probably get both for less than 100 with a spare pump...

ECU: I recommend considering a microsquirt/megasquirt, or one of the many other standalone systems. The Audi system is EXTREMELY complicated and has one of the hardest learning curves I've seen. Its really powerful and can be paired down but its way overcomplicated for you who is not using the Audi dash. You can also do flex fuel with the aftermarket systems and have internal boost control or water injection control.

Axles: You can change the flanges on the transmission for the 100mm axles, or go with custom axles. The 100mm flanges are difficult to find but are on the standard boxster transmission.

Front motor mount: Not needed. Mike and I run without.

Rear trans mount: Use 911 sport mounts ($30?) and then fab up something. Mike built a cradle. I built separate mounts from tube steel.

Exhaust: Lots of different manifolds available. I would go with a bottom mount manifold/log manifold. Top mounts make it tight to the 914 body, while bottom mounts can be much more forgiving. I Have the APR Iconell manifold. It'll never crack or break and is very good flowing but finding one is almost impossible and expensive. I had one left over from my APR stage 3 kit from my Audi. They are a PITA to mount though...

Intercooler. A small air to water could be plenty and compact. You wont get the airflow for an air to air system.

Turbo: GT28(RS?) is a great turbo. feels like a v8 with its instant power. You can also look at the many hybrid turbos on the market that will give similar power but on a bolt on system to the factory manifold. Look at Frankenturbo

Chip: See ECU

Injectors: 440's will support about 275 wheel (I make 260awhp on a GT28RS almost maxing out the system on a stock fuel pump), 660's will leave you with headroom for E85 or some mixing.

Hydro clutch pedal: There are some members that have made some kits that are not bolt in but surely are a decent starting point. I cant remember the name. A search should find it.


I did 260awhp on 19psi or around 330chp. Very very fun motor when it was in a 3300lb car. Mikes car makes about that and is a blast.

My axle lengths are specific to my "non-plunging" 930 CV joints. The axles need to slide in/out because the CV does not.

Make sure you measure. the transmission placement front/rear will change axle length.

ECU: look into Speeduino. Like Megasquirt with same software but newer tech and half the price.

Gauges: Speedhut. Not cheap but worth it and look appropriate.

Thank you for the tips guys. Smart advice.

Greetings JB6000:

The Audi transaxle looks very similar to my Audi 6 spd 01X which has 108 mm flanges. I had adapters machined to take the 108 mm >> 100 mm Porsche 944 / 911 CV's. Because the ttranaaxle is offset (centre line) I started with 5/8" adapters recessed bolts to Flanges, used 944T CV's and 911 axles, I believe the axles were 18.5" and 20" (going by memory). After several months realized that the right axle was too short, but after some re-measuring decided to keep what works and then machined thicker adapter on right side; seems to be the best solution. (custom axles would be costly and difficult to source).

Sorry I don't have more in common with your project since I am running a Z06 LS6 motor out of a 2004 Vette; and closer to 400HP. Enjoy the project and wish you good success. Allan

Click to view attachment

A 2001 Boxster S 6spd
B Trans output flange -- 95 MM bolt circle diameter. 108mm overall diameter.
C Location of adapter/spacer (if used)
D 930 CV
E Axle 28 splines on both ends (19.5" and 20.5" maybe)
F 930 CV
G Location of 914 flange

D and F ? 930 CV

https://www.pelicanparts.com/More_Info/9303...BSABEgJItfD_BwE

E ? Axle

https://www.pacificcustoms.com/ac525207.html


Another: https://swayaway.com/product/axle-set-porsche-930-28-spline/

Hi JP6000

Appreciate the follow-up comments and questions; unfortunately I am traveling and don’t have access to the files back home with access to more specific details as the build records so need to go back to reference things. Regarding your layout diagram above, the details are correct except the following items:

D – mine uses 944 turbo C/V’s and reason being they are stronger and excellent axle angles.
E – Axle measurements will be different as previously mentioned, as well depends up location of your transaxle and ride height of the car. I’ll update later next week on axle length and adapter thickness.
F - it is my understanding the C/V’s are measured by their Outside diameters Audi is 108 mm Porsche C/V’s 914, 911, 944 many at 100 mm, 930 & newer Porsche are 108 mm.
G - mine was converted to 5 lug 911 flanges / hubs.

Hope this will assist you in the process of your project.

Allan

Allan,

Thanks for sharing your set up.
Thanks Mike and Andy and Chris.

I would not even have a clue without your help.

I guess the axle length will be the last thing I determine, and measure, after everything is mounted.

This thread will be here when you get home Allan, Safe travels!

Jerry

944 clutch master cyl.
Adaptor cnc and crinkle powder coat.

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Also I bought Renegade rear transaxle mount for the Boxster S trans, and I bought a Shifter and Cables.
With the Renegade rear mounts my front to rear transaxle placement has been defined.

Need to fab motor mounts next ...

Side view.
I made it fatter so I could drill and tap the 4 Bolt holes deeper.
Plans available on this forum.

Still have not torn out the V8.
It drives.

The wiring was redone by PO. When I turn the key off the car keeps running. I think the alt. is charging the coil … ?

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I think I need a 12v 1 amp diode so the alt does not feed the coil +

Not sure about the diode but sounds like you may be getting constant 12V at the coil instead of switched 12V from ignition?

I need to fab some motor mounts parts next.

Agree.

Has anyone Putting a Boxster S transaxle in a 914 ....

Used the Boxster axles, hubs, rotors, calipers?

Just wonder if it's been done.
I found some threads on it.
Looking in to it.

If you look on youtube for 914outlaw you will find more great infomation on this build.
Andrew has laid out how to set up a very efficient radiator system and water to air intercooler for this swap, on a budget.

Mike Bellis mentioned these cv joints:

https://www.rcvperformance.com/ultimate-930...-28-spline.html


Nice parts! Thank you Mike!