Hi there,

Here is the last picture of my car, I put BBS Motorsport rims on it thanks to Gert!



I still have a project in mind: transform my 911 into a GT2 like. Appart from the body parts, I think about updating my 272bhp engine and convert it to a twin turbo ~400bhp engine.

I could see in the forum lots of posts about installation of turbochargers on atmo 993 but nothing about a conversion using standard Porsche parts.

Is it that complicated to adapt my basis engine and make it a twinturbo engine like the standard one?

Thanks for sharing your thoughts

Cheers.

 

nono993
Very nice car!

I am not exactly sure what you mean by using Porsche parts. The engine designs are not the same. A N/A engine has higher compression, twin plugs, different intake system, different P&C, different heads, different exhaust system, different gearbox etc..

Protomotive does a N/A to turbo conversion based on Bosch Motronic, I don't know many others who use factory Motronic, this is as close to factory as you can get I guess? He can use KKK turbos if you wish instead of his usual Garrett setups.

You are better off by selling your engine and going to a twin turbo engine is you want to keep it very close to factory configuration IMO. You will need to think about brake upgrade and suspension (if you don't already have it). If you ever do, keep your car narrowbody, don't go GT2 look, it will be much faster!
Jean

 

Hi Jean, thanks for your swift reply!

What I meant is use Porsche standard parts instead of kits sold by manufacturers having nothing to do with Porsche parts like intake, turbos, etc.

I tried to find a twin-turbo engine in Switzerland, almost impossible... My mechanics knows waht to change be he needs to tell me how much it'll cost...

My 911 already has 993TT brakes and RS chassis. I had a 8/32 installed as well as a RS clutch and flywheel.

By the way is there a real difference between the narrowbody and GT2 widebody in terms of performance?

 

Nono

It can be done for sure. It depends how close you want it to be to a 993TT engine. The closest you need to be probably is by using Bosch Motronic with its knock sensors, Mahle Pistons and cylinders, and KKK turbos. You keep your throttle body and manifold too. Trick is to find someone who can program your current Motronic to twin plug, and a turbo setup based on pressure sensing which is what Protomotive does, you won't find many who can do it.
Try talking to Sportec, Gunther and Ueli is probably as good as it gets, but it will be expensive.

As far as the difference, aerodynamic drag is very important, your wing alone represents about a 17-20hp loss at high speeds based on some rough guesstimates. The wide body, GT2 flares and wider tires are a killer to performance, expect the (converted) loss of another 30hp at least if you have the wheels and tires I have 10FR (265) X12 Rr(315)..In summary, vs. a narrowbody, stock winged car, I would expect more than 50hp (equivalent) difference at high speeds...This is just estimates, I will soon do some tests to confirm.
GT2 wing aerodynamic drag .
Cheers

 

nono993,
I have to agree with Jean. It is definitely cheaper and easier just to swap the engine instead all the work of transforming and the modifications the regular engine to a TT engine.
The narrow body is faster due to the better aerodynamic form of the body.
I propbably can help you finding a TT engine since one of my sources is selling one now. Let me know.

 

Thanks for your remarks Jean, tha'ts definitely worth to read...

From an aerodynamic perspective, even if I loose some HPs by mounting the GT2 aerokit on my car, it will be largely compensated by the increase of power after the conversion My RS has 310bhp for the moment and I expect at least 400bhp after the conversion. On the other side I'd love to have a car looking like a GT2 as it's my favorite version of the 911! :P

 

I may be interested by the engine you're talking about. How much would he sell it? Thanks for posting this info

 

I know what you mean!!

 

Sure and you're car is simply gorgeous

 

I have a C4S which the previous owner converted to a Turbo using factory parts. You wouldn't want to try to convert the NA engine in your car -- better to sell it or sell the whole car and get a Turbo. I have no idea on the Swiss market, but if you want to start with a narrow body, strip it, bolt on GT2 stuff (of which you appear to have at least two components) then adapt the transaxle and bolt in an engine driving in 2WD, I think you'll have a great car.

In USD, I'd budget of $50K to make it happen. You might get away with $35K with some luck and "sweat equity" in the labor costs but this is going to be a helluva project.

While I appreciate the "factory only" approach and I think that's the right way to go, I do think you should look at the GT2 and Turbo owners for their upgrades. Things have happened in the last decade, so unless you're trying to build a retro homage to the GT2 with accurate and faithful reproduction of the details, you'll find it better to look at modern intercooler, turbo and engine management technology.

If you get down to doing the work, I'm happy to answer specific questions. Here's some high-level stuff.

In short, the power plant swap is very simple. Some of the wiring will be a chore, but everything is based on plug connectors, nothing surgical.

You'll find problems with transmission and instrumentation -- different part numbers, not all listed in PET and some mechanical differences. Some parts for the 993 are falling out of ready supply even if you pay for AG shipping. RS wheel carriers and the 964 manual steering rack come to mind. I don't know you'll even be able to find the factory auxillary oil cooler. Maybe. Otherwise, there's one or two very good (actually better) after-market units. Browsing the 993 Turbo forum for upgrades will give you ideas on how to build a better GT2. : )

If you want to make it a track car, things get a lot easier. If you want a "pure" Porsche street car using stuff with part numbers, you'll be spending money on things like instrumentation, so budget accordingly.

There are shops in the bay area that have done beautiful work on "twin turbo" variations on the theme. There are also shops that have done the most disgusting hack work that nobody could imagine much less actually doing ... while you have a tech identified, I suggest caveat emptor ... : )

 

The protomotive stage II costs something like $28k or so and includes a top-end rebuild and lower compression (factory I believe) pistons. Jean, is your motor a protomotive motor?

http://www.geocities.com/protomotive/products.html
http://www.geocities.com/protomotive/pricing.htm

 

Yes my engine was built by Protomotive but the base was a TT engine not a N/A.. For a 500FWHP upgrade, you don't need to do much work on the internals on a N/A engine..

 

Hi,

I am in the midst of converting a 993 C2 94' to twin turbo. I am based in Lugano. That might be of interest if you want to touch base.

The car already had pss9, RS antiroll bars, front strut, shortshift, Recaros....

I did not want to go for aftermarket compressor kit or turbo conversion.

Ended getting a 40k mile TT engine complete + clutch + wire harness + rear axles + big reds + exhaust a number of ancilaries for round $22k in the US. I ended paying another $5k for a tt gearbox after exploring different options to keep mine and abandoning (essentially, mods to cope with the additional torque and get correct ratios). Got all from LA Dismantler for Porsche (www.911pcar.com). Todd, the principal there, spent much time and treated me really well. They often have 993tt engines for sale.

Add shipping from California + our dear import taxes

Also got 964 3.8 rsr tail and RSR front splitter / wing and RS side skirts (black). This is the only negative for me, as I like the looks without tail. We'll see what the downforce wonders really are round the ring...

Other upgrades will include replacing the stock LSD, a lightweight flywheel, maybe sports clutch, brake air scoops, braided hoses.

I plan to recover EUR10k from my engine and gearbox. 67k km, 290 hp at the wheel (chip, throttle body, K&N, Gemballa exhaust).

All in all, I did not want to sell my car, with many great mods, to get an AWD. I like the narrow body, the rear wheel drive is a must and TTs remain very expensive in Europe. The main reason to get a tt would be if you intend to resell.

The job will be done in September. Will keep you posted. My main worry is the TUV.

Vartan

 

Vartan and Mono,
Be careful, because the Swiss are pretty tough on car modifications. As I remember, you are not allowed to modify a street car's engine in excess, I believe 10% hp. (An AMAG mechanic in Zurich had told me this). My advice: first check up what the exact rules are. I would think that Sportec would know.

Good luck.

 

I have seen you around in Lugano. Great looking / sounding car, and great rims. We should go for a drive one of these days.

Agree with you: TUV will be the difficult part. That said, this is also why I went for porsche parts, including the engine, as opposed to tuning. I also believe it depends greatly on who will bring the car to the TUV...