Performance upgrades for a 912 engine

[Bathtub57]

I am just wondering...

Has the performance potential of the 912 changed much over time? What can be done now with a 912 engine that couldn't be done 10 or 20 years ago. What induction can be fitted and used reliably to improve performance - and I would include fuel efficiency as a performance parameter - turbo, EFI, electronic ignition systems, do,they hold merit?

How does a worked on 912 compare to say an early 911 engine for BHP and torque? We all know 912's are the better car of course.

If I am right the 912 would have left the factory with around 90 BHP, I wonder what some of us are getting now?

I've driven getting on 5000 miles this year in my 912 and it's been great but there is a worm in my head telling me to start investigating some upgrades. I'm interested to hear people's views and opinions, experiences good and bad with nothing off the table. Electric conversion anyone?

[Ashley James]

A VW Type 4 engine modified to suit as discussed on the 356 Forum is your best bet, but it’s quite costly.

[smallspeed]

As a bolt on option I’d imagine efi, crank fire (hidden) and injection with Weber pattern throttle bodies would be a good uograde.. maybe not a huge step up in peak figures but driveability and power delivery plus economy

[Jonny Hart]

I'd really like to try our CDI+ ignition on a four banger. Given that the head is also a large hemi design, 2V with an offset plug, I would have thought you'd get another 10% power at least.

If you're up for giving it a try, give me a call!

[Bathtub57]

The type 4 is a great motor, I have one in my 2 litre Bay. The 914 or Raby version would make for a strong motor.
Crank fire ignition and CDI sound a lot more practical - has anyone got practical experience?

By the way this is just a rambling thought provoking thread, I hope.

[neilbardsley]

Do a search on the 356 and 912 registry about this. There are lots of options but in the end you can only get so much from this engine. Here are somethings I've seen people do

The simple stuff

-> Big bore kit to 1720
-> Higher duration cam. However, this can make the car not great to drive on the street

with a better street cam and big bore you can expect to get between 100/120 hp

Next you have to increase the cam duration or increase the bore or move to cdi twin spark option (or all of them). Often this means getting a better crank and cylinder piston set. If you google Wilhoit porsche he has a kit for taking your engine out to 2.1l Which will get you to about 150/160 hp. John Benton has a full crank fire twin spark option which produces about the same power. However, these options are expensive. Maybe £20-25k for an engine. The people to speak to in the UK are Ian Clark WPS and PRS.

I will you you I would go to a rolling road where you might find 10hp for £200 then if you still aren't happy consider letting Ian Clark do some head flow work. Then you if still aren't happy consider buying a Boxster?

[smallspeed]

I helped EFI a friends type 4 (in a vanagon) last year - tim (impmad2000) helped with the initial tuning. The installation dean used is a bit more odd-ball (as it would be with dean!) in that he modified the standard injection components like the airbox, manifolds etc. (even the standard ecu case and wiring) so its pretty much invisible. Interesting choice for what amounts to a hidden engine
I think for a 912 you could do something fairly bolt-on, the only thing that would need to be made-up is a wiring harness and some way of connecting this into the main loom of the car -

You will need a high pressure fuel pump - if its anything like a VW beetle arrangement you can fit a Subaru pump with an adapter plate
You will need a megasquirt or VEMS ECU (or Omex, Motec, etc if you're feeling flush!)
You will need a wiring harness to suit the above
Regarding throttles I'd go with a set of weber pattern (IDF/IDA/DCOE) throttles to suit whatever weber manifolds you can get for a 912
Throttle linkage should be simple - a lot of the weber pattern throttles fit-up to the standard "beetle" twin-carb linkage, those that don't usually have a cross linkage available which works with the type 1 engine layout
Crank triggers are widely available for the type 1 and 4 engines - my mate dean used one of the ones from dubshop which is 100% hidden. They now offer a "package builder" option, which might be a simple way of getting everything all in one..

https://thedubshop.goodsie.com/vw-efi-p ... ge-builder

Its not going to be a 2hr "bolt on" job, but if you use the right parts its 100% reversible and should net you decent gains without removing the engine or splitting the case. To the untrained eye wouldn't be that noticeable which is a plus - you'd retain a lot of the look and feel of an engine on twin webers.
That said, once its all in and set-up it should be a simple (3-4hr) task to "unplug" and revert to standard (or thereabouts) for MOT / Tax purposes, if modifications are a concern..

[mycar]

...... Then you if still aren't happy consider buying a Boxster?

Definitely sounds like the cheaper option.

Here are the Willhoit articles Neil refers to :-

356 engines but you can follow the developments and see the dyno results for a whole host of upgrades.

http://www.willhoitautorestoration.com/ ... 202010.pdf

http://www.willhoitautorestoration.com/ ... %20Dev.pdf

[hot66]

as much as I love modifying cars etc , leave it stock & enjoy it for what it is . Just concentrate on keeping it running & reliable .. all IMHO

as Neil says, if you want performance buy a boxster or 996

[Ashley James]

I have an old 987 and can’t recommend them highly enough.

[Bathtub57]

Some really interesting replies. My question was what upgrades can be done now that couldn't be done 10 or 20 years ago and it seems the advancements are around ingnition and induction but many tried and tested upgrades form the basis of performance upgrades still.

As a side note I'm surprised that some answers on a 'maverick' classic Porsche site would be to keep it stock or buy a boxster? My car is not stock and is unlikely to ever become stock and I drive it pretty much every day.

[hot66]

depends what you're trying to achive

easier & cheaper to build a hot VW based ( type1 or type4 ) motor if its power youre after and put the original motor on a pallet in the garage.

I've come from the modded car / VW side of things and don't keep any car I've got 100% stock, but sometimes its better to leave original motors alone as you can end up spending a fortune to achiev very little

[smallspeed]

its amazing how much driveability has been improved even on things that are running alpha-n or hybrid management over the last 20yrs or so - my 3-series was swapped from a "barn-door" air meter to a proper MAF and newer management. It was a nice change at the time, but only in the last 6-8wk when it was changed back again (due to me cooking the ECU and not getting around to sourcing a replacement) have I truly appreciated what a difference it makes!
the level of control and driveability you get from a more modern set-up is a brilliant way to enhance what's already there without any permanent modifications. Its never going to turn a stock 912 into a 10 sec car, but it will certainly make it more driveable and pick-up a few ponies along the way
james is right though, if you want more than just bolt-on stuff, then buying a pre-built 2276cc engine or something similar, and keeping the original on a stand in the garage is a great option to avoid blowing a lot of cash, or risking your original engine case, etc.

[impmad2000]

A mate put a crank fire on a type 4 in a camper, Ben (Smallspeed) have you got a link to Deans work ??

[smallspeed]

I sent him a message earlier Tim, not heard back yet, but he does have a 2wk old kid to contend with now
I'll post his spec and a build thread when I get a reply