srupp1969

Hello all together,

as I am new to the 928 forum at rennlist, let me introduce my self in brief.
My name is Stefan Rupp, 35 years of age , living and working in Munich/Germany and Porsche owner for more than ten years (at the moment 928s4 model 88' and 944s2 cabriolet model 90').

During the years the issue of supercharging the 928 has been present in the german 928 community from time to time and only few companies were offering services in this direction (for example Koenig, Lotec and Albrex).
The prices were and still are horrible (arround 20k) as well as quality and lifetime of the engine.

Nevertheless I am seriously considering about purchasing a supercharger kit for installation in my own 928.
I read so much about this topic, but to make a proper decission for myself I need the help of experienced kit-users here in the forum.

Please give me your personal feedback concerning prices/quality of the parts/ease of installation/performance/kits complete for bolt on/company service.

Which boost level allows the 928 engine (euro spec) without modifying piston/crank/crankshaft? Intercooler demanded or not?

The goal is to achieve roundabout 450-500 rwhp (porting heads and racing headers/exhaust sytem a must at this stage?).

Thanks a lot to all of you for your assistance and greetings from Bavaria,

regards
Stefan

sweanders

Hi Stefan!

I live in Sweden and will probably get a SC installed within this year. It was planned to get Andy K's (GoRideSno) kit installed during easter but for reasons on my behalf we have chosen to do this later on.

I've done a bit of research of installing superchargers on the 928 in Europe and haven't found anything interesting. If you do come up with something perhaps we could do this as a joint venture?

Btw, you don't happen to know anyone selling a 944 automatic in Germany, looking for a friend.

Daryl

Hello Stefan
Try using the "Search this forum" at the bottom of the 928 forum page. Put in "supercharger" and see what you get.

Best regards

srupp1969

Hi Anders,

these companies in Germany/Austria are delivering kits for the 928:

http://www.koenig-specials.com/ ; then go to news/end of page/kits porsche
http://www.albrex.at/flash.html

The Koenig Kit is originally delivered from Albrex, they only changed the stickers on the parts.

Stefan

GoRideSno

Srupp1969,
Do you know of any performance figures for the kits you speak of such as 1/4mi times?

My favorite is the 2.3L twin-screw system with air to water intercooler in the V of the engine by 928Supermodels. Price is less than $6k USD.


Andy K

mspiegle

I agree with GoRideSno and sweanders. I have one of the 928Supermodel kits from Andy installed on my car.

The kit is well designed, functional, reliable, and comes with a very nice price tag. My particular kit was only a few thousand for a non-intercooled Eaton supercharger. I'm very impressed and will be moving up to the twin-screw intercooled system very shortly.

Lagavulin

Greetings from USA!

For starters, you can read the links in my sig. I am very happy with Tim Murphy's supercharger kit, it's complete and costs $8k. EVERYTHING is included to do the installation, and all the components are high quality.

Here are pics of the install:

https://rennlist.com/forums/showthre...5&pagenumber=2

Since you have a target of 450-500 rwhp, the only kit available that'll come close is Tim's. It runs 8 psi intercooled, and will put out around 435 rwhp. At that boost level, NO engine mods are required.

If you do a search, you'll find posts by 'Gretch', 'jorj7, and 'Old & New' who have done the same installs. Here are some easy ones I found of Gretch's well documented install:

https://rennlist.com/forums/showthre...t=supercharger

https://rennlist.com/forums/showthre...5&pagenumber=1

https://rennlist.com/forums/showthre...harger+install

https://rennlist.com/forums/showthre...l&pagenumber=1

https://rennlist.com/forums/showthre...l&pagenumber=1

https://rennlist.com/forums/showthre...harger+install

bcdavis

I think it also depends a bit on what kind of fuel injection your car is running.

If it's a late model s4, Tim's kit seems to be the way.
Andy is doing the earlier s4, and also the s2 soon...
And 928 Motorsports has a kit specificaly for the CIS cars...

srupp1969

@daryl,
thank you very much, there are about 15 pages to sort out - I am going to start immediately!

@goridesno and mspiegle,
the kit looks nice and the pricing is also very interesting, the only problem is, that I need someting that has a factory appearance when you open the hood, to hide it from the cops an authorothies here in germany.

@lagavulin,
thank you very much for your list of links.
Very nice kit , very clean installation from the first view and very impressing dyno results.
Think I should go in contact with Tim for futher information.

@bcdavis,
it is a late model s4, so that I am more tending in Tims direction.

@all,
thank you very much for your feedback, so far.
For the first action I have to sort out all the infos and I hope that I am allowed to come to you for further questions.

Kind regards
Stefan

Sab

Hello Stefan,
greetings from Miami. I grew up in Munich and frequently visit.
Would be interesting to see if a supercharger install will hold up on a typical run on the German Autobahn. I used to go with my '84 928 from Munich to Hamburg (~ 900 kilometers) every other week or so (I remember my best run was well under 5 hours). I would typically cruise for hours at 250 km/h and sometimes stay at full throttle for quite some time. I wonder what would happen to a supercharged motor running at full throttle for two hours.

regards,
Sab.

bcdavis

As far as hiding the supercharger, you will have to come up with some kind of cover for the engine, or perhaps paint the parts flat black, and make them look stock. Like a porsche part tag or number sticker put on the supercharger, etc...

The other good thing about Tim's kit, is that it is not too hard to remove it, to pass an inspection...

It all depends how often they check you car.

But I think it would not be too hard to remove it.

Just keep all your old stuff in a box somewhere.

mspiegle

in my opinion, the kit that Andy and I mention looks way "more stock" than the other kits.

Just don't use funky-colored wires like I did...

mspiegle

@Sab
It isn't quite 2-hours @ WOT... but Andy did attend a POC meet @ the willow springs race track and had absolutely no problems running hard w/ his setup.

bcdavis

Quick Carl races his supercharged CIS 928 all the time as well...

As I mentioned before, I actually look forward to one of these engines blowing up, so we can see what the weak link is/was.

We already know that some of the cars that died under boost died due to detonation. So with the intercoolers, and proper fuel management, the new kits seem to be free of that problem.

So the next test, or question, is if the rest of the engine will take the boost during hard driving.
It seems like the head gasket could be one issue.
But that is not a hard issue to deal with.
So I really would like to know if the rods or other parts are really so weak,
or if the bottom end on these cars will still last for several hundered thousand miles...
Time will tell.

mspiegle

its great you're enthusiastic about 928s blowing up, but I personally plan to keep mine intact =)