Ultimate ST thread

More on the aero effects of the ST vs. RSR. Paul Frere's Porsche 911 Story gives the following lift or down force figures for the 2 cars as they raced at Daytona in 73, and compared to the rear spoiler developed later in the season known as the 'Mary Stuart Collar'. The data was from wind tunnel tests after the Targa Florio race in April 73.

152 mph:

ST deep front spoiler, no rear spoiler (TH car)
front (downforce) 60 lb;
rear (lift) 320 lb

RSR extended front air dam, ducktail
front (downforce) 60 lb;
rear (lift) 126 lb

155 mph:

Mary Stuart style rear ducktail
front (downforce) 22 lb;

rear (downforce) 77 lb

One can imagine the braking/handling issues for the STs (especially Toad Hall's entry with the deep air dam) coming off of the long high speed oval into a tight turn with downforce at the front and over 300 lb lift at the rear.

Raj,

Page 2 and 2A. might help......

No mention of 'RSR' anywhere in the Sales Bulletin No. 72/98

Cheers

Raj,

I don't know anything about the Strahle car or the Freisinger car.

The front mounted oil cooler is interesting though. I wanted to find out if the front cooler was with the car when it was imported by Vasek or if the two fender coolers were in the car. In a previous post I mentioned that a 907 front cooler was added while with Vasek, but I wasn't sure if that one replaced a cooler that was already there or if it replaced the two fender coolers. It is understandable that Carl Thompson wasn't able to recall this information as its been about 35 years now. The braided oil lines that ran through the passenger compartment and into the trunk to feed the front cooler were put in at some point but I don't know when this happened (Europe or Vasek). The car has signs of the usual external hard lines running along the passenger side.

What is your impression of the Stahle car? If the Strahle car you pictured here raced throughout the '72 season is it possible that it could retain its original engine case? I don't know. The 0494 car was yellow and had the fuel filler in the same place, and at some point had a front mounted oil cooler. It would be helpful to find a chassis number for the Strahle car.

Matt

long stroke camshaft ??

MFI version of Typ 906 camshaft, center oiling, three bearing.

Specs:

906 Lift I/E: 11.73/10.24; Duration I/E (deg crank) 281/251; Lobe Center (deg camshaft) 95; Intake Valve Overlap 6.7*-6.9*\

37yrold911: Oh, now I get your question; yes Raj meant crankshaft - the new 70.4mm throw crank.

"No mention of 'RSR' anywhere in the Sales Bulletin No. 72/98"

Chuck, Raj:

Here is a scan of the fly page of the Spare Parts List Carrera M 491 2,8 ltr. competition type dated Febr. 1973

NOTE: It does not say RSR anywhere on the cover or anywhere on the list of parts inside.

That is because the car was not designated an RSR by the factory.

The name RSR was invented by Erwin Kremer to denote an Typ RS Rennen (race) or RSR for short.

The factory did not pick up the name until it was popularized by the motoring press.

The factory did use the RSR designation on the cover of the 74 RSR 3,0 spare parts list, well after Kremer popularized the term and it had entered common usage among Porsche enthusiasts around the world.

My mechanic just handed me over this photos.
His father in-law owned this yellow 1972 Kremer - Porsche 2.5l in Switzerland from 1974 to 1990'ies.
Got sold to a german dealer.
I dont have chassis numbers but might have access soon.
Edited March 2013: confirmed its 9112301417
Who knows this car or its racing history ?

In racing trim. date unknown. Kremer Porsche. 1972 chassis.
http://img8.imageshack.us/img8/3438/dsc02096y.jpg


The car in about 1974 with his then new owner.
Note s/T flares similar to factory 72 models.
http://i1077.photobucket.com/albums/...psc541a86e.jpg

Front spoiler has similar 'fog' light grills as seen on white 72 factory car (page 2)
(red) ducts provided additional air for front brakes
(info by mechanic who remembers driving and servicing the car)
http://i1077.photobucket.com/albums/...ps7ca5f98d.jpg

In 1982, the car got painted silver but kept his twin plug 2.5l.
http://i1077.photobucket.com/albums/...s8cbae528.jpeg

Engine...
http://img3.imageshack.us/img3/3977/dsc02097.jpg
http://img26.imageshack.us/img26/1405/dsc02100b.jpg
http://img291.imageshack.us/img291/9262/dsc02102q.jpg
http://img8.imageshack.us/img8/1342/dsc02101k.jpg
http://img26.imageshack.us/img26/8203/dsc02099.jpg

hello

What would be the functionalities of the parts attached to pump ? I never seen a system like this. Is it a inboard iddle system for starts. Maybe there is a lever (between the seats) to activate it ?

Manu, Raj

What strikes me is this 2.5l 1972 has the same factory equipment w front spoiler and S/T flares like period 71/72 factory shots.
Also, it has the electrical cut-off close to windshied area similar to factory cars.
Maybe Kremer bought one of these 72 shells and rebuilt the twin-plug engine.

I dont know anything more about the but I heard the car is currently in Germany and in used on historic racing.
As stated before, at some stage it was repainted in silver but originally light yellow.

Factory shot of a similar equipped 911 (see page 2)
http://img24.imageshack.us/img24/421...1ca469afo2.jpg
The "swiss" car:
http://i1077.photobucket.com/albums/...psc541a86e.jpg
Here is again the engine, chassis repainted 1983 in silver.
http://img3.imageshack.us/img3/3977/dsc02097.jpg

Raj
Did you ever talk to Bytzek about the 1973 RSR? I have his car, the one with the big Maple Leaf on the sides.
I have the blank ordering papers for the RS, 14 pages of 8 1/2 X 11. including the page that must be signed that you would not use it on the street. All I see in the papers are references to the RS, and conversions, no RSR reference

QUOTE=varunan123;194111]Chuck posted this porsche VW circular of Dec 72-suggests that indeed at that time it may not have been seen as RSR to order.I will talk to harry Bytzek who took delivery of the first customer RSR and will see if it was ordered as a carrera RS M491 or RSR.There are other references i will post.The marketing dept took delivery of the RSR prototypes in Dec 72.

Raj

P.S thanks chuck[/QUOTE]