First, a little back ground on me as I don't post here alot: I'm an Automotive powertrain engineer, and i've worked on base engine performance development, Analysis and Vehicle calibration. I've been involved in Jaguars and Aston Martin engines.
I currently work in Germany in the same field.

I own a 993 Turbo.

Last week I met a contact I have at Weissach. He is a quietly spoken humble man who had worked there for many years.
When I enthused about the 993 I think he was a little taken back but probably pleasantly suprised.
He said that because the 993 is an old design now, he didn't mind supplying me with technical data to do with it's engine, including Combustion burn rate, Volumetric Efficiency data and full load ignition data. Unfortunately he couldn't give me data for the turbo.This is an engineers wet dream!

From the data I have I have been able to construct a gas-dynamics/thermodynamics engine performance model. Now a little about these cycle simulation models- when they're calibrated they're very very accurate. Ok, so they're perhaps not quite as good as an OEM Schenk Dyno but they're certainly produce more repeatable results, and I would always rate them above back street rolling road vehicle dynos/dyno jets that aren't usually calibrated well and there are alot of vehicle driveline unknowns.
I KNOW, I used one, extensively in league with an engine dyno during my work in the performance development of the Aston Martin V8 Vantage engine, along with work I've done on various XJRs and XKR, XJs , S types etc.

I'm not sure but the dyno data and model data look like they're from a M64/05 rather than the Varioram M64/22. I hope to morph the engine into an M64/60 turbo, as Borg and Warner 3K turbo maps are relatively easy to obtain and I can measure all the geometry off my very own engine.

Question is, would anyone here be willing to supply me with lengths and diameters, possibly volumes of the intake system of a Varioram 993? The exhaust system dimensions could also be handy (from cyl head flange to silencer to tail pipe). Better still, is there anyone here from Germany, near where I am, where I could visually inspect their car?

My intention is to validate the conceptual model further by first morphing it into a Varioram engine and THEN into a Turbo 993. If it changes successfully each time, then I have a useful predictive tool!

I've already carried this out with the BMW M20 small six - calibrating an M20 2 litre, 2.3, 2.5 and 2.7 litre. The culmination of that work was my own cam design and intake layout along with a unique sound quality- but it was quite a few years work.

For background information on simulation codes like this (these are commercial codes- not basic stuff like "Peformance trends")
http://www.ricardo.com/media/pressre...e.aspx?page=16

http://www.gtisoft.com/broch_gtpower.html

Both are OEM standard tools and very expensive, I'm just lucky to know and have access to them.


Cheers

 

I can't help you with the data - but damn that's an awesome project!

 

Hummm... engineers are strange people...

 

Why go the Varioram route ? The turbo has more in common with the M64/05 .

Inlet manifold is very similar but no resonance cross tube for the turbo . The N/A exhaust layout is in many pictures so a simple tape measure job on your own car will give you pretty close pipe lengths. The cat section for the M64/05 is different US to ROW .The US version has a central divider to seperate flow for OBDII . The ROW is not divided and has a better ? extractor effect.
Turbo is completely seperate .
Cam data is commonly available, as is valve size etc for the M64/05 and your turbo .

I would have thought that a good understanding of the M64/05 N/A and turbo motor differences would allow you to put together a reasonable turbo model.

All the very best with the project.

Geoff

 

I guess you're situated near Stuttgart or Munich! If you were closer from Belgium, it would be a pleasure to let you inspect my car.

 

Thanks for the info Geoff, the main reason for tracking as many engine variants as possible is to gain more confidence in the correlation of the model.
There are so many adjustment variables in the model- it's sometimes neccessary just to be sure (heat transfer numbers, surface friction values etc etc).
I have the entire profiles for the earlier car, and from this I can get the main features (height of ramps and ramp rates, max accels, jerk etc etc) and generate profiles similar to that of the factory based on the limited info I see in technical books like Frere and Anderson (i.e peak lift and IVO, IVC, EVC and EVO timing etc etc)- this should probably be accurate enough.

As an aside, I've seen alot of dyno data of many engines over the years, benchmark and otherwise, including BMW Euro E36 M3s, Honda S2000s etc etc. All I can say is that I'm impressed at how low the backpressure is compared to other "sporty" cars and how low the intake manifold depression is.

The Backpressure is similar to an original 240 Bhp 3 litre V6 Jaguar S type , but the engine makes alot more power- and therefore puts through alot more gas flow so is all the more impressive.
The burn isn't fast- as you might expect for such an oversquare "Hemi" even with twin plugs, but it doesn't seem to need alot of ignition advance compared to other two valves such as the BMW M20 engine, The Chevy Corvette C5/C6 or a Mercedes M110 twin cam 2.8 straight six.

 

I'm situated close to Frankfurt. However I have been known to drive back home via Holland and Belgium-back to London quite a bit so I might take you up on that!
Specifically, I will be having my 1970s BMW fully restored by a specialist in Holland- so it isn't inconcevable that I could drop by!
Cheers!

 

Have you checked Adrian's 993 book, and also the workshop manuals for the data?

I would be really interested to hear your take on 9m's setup, where they're claiming something like 100 hp/liter (i.e. 360 fwhp) IIRC from their custom heads, cams, and sport cats. A lot of us want to buy that setup but are balking since it's still so new and seems almost too good to be true. (there has been much discussion of this setup in case you haven't seen it)

 

OK, I had a look around and found Porsche Service Information Technik

499 520 96 which has some of the information you asked for.

Below 5000rpm the intake runner length is 475mm , above 5000 it is 240mm.
I believe that is from intake valve to chamber.

Below 5000 the intake volume is quoted as 5.8 dm3 , above 13.5 dm3.

The resonance tube area is 0 below 5000 , 104.2cm2 from 5000 t0 6200 , and 161.2 cm2 fro 6200 to the rev limit .

I used to work for a car company in Munich . I guess that narrows it down !
I also have friends in the calibration business, so the name Ricardo means a lot .

Be interesting to see how you get on with this project.

All the best

Geoff

 

Thank you very much The Other Eric, do you have any links to that book?
I haven't been up on the discussion on 9M conversion, however I'm familiar with some of the claims in other forums. I have my own opinions even just from reading your post here. If you want I'll share them with you IN Private.
Red Rooster, I'll be sure to look that book up! Wow! So you used to be in engineering itself? I myself have worked in calibration.
How did you end up in Canada? I've been trying to emigrate for a while now, but no success so far....

 

You're welcome! I work abroad, so let me know well in advance when you should come and I'll adjust the planning.