10,000 RPM Tach/Rev Counter - What car is this for?

[Concept42]

12V30000 Imp

But no part number...

[Concept42]

Actual Tach/Rev Counter and Speedometer in my 1973 RS when I purchased the car...

[Concept42]

I was able to find the part number didn't realize it was so small. The part number on my Tach-Rev Counter is 911 641 304 00.

So what car would this be for with an 8/73 production date?

Thanks for help.

[BOYER73S]

8/73 is for a 74 car and as you have been advised most likely an RSR, nice find.

[Concept42]

Thanks for all the information. We have been able to ascertain this Tach/Rev Counter came from a 2.8 RSR!

[HughH]

If so it was probably a factory replacement one for the original one in the RSR as it is dated after the last 2.8RSR was made

Also it has the 73MY, and earlier, silver center (as opposed to the 74+ black center) a sign to me that it was a factory replacement item rather than originally fitted when the car was made.
Great piece anyway whatever its origin

[Concept42]

Hi Hugh. What do you mean it was a factory replacement? Date code is 8/73 and I did not know that was after the last 2.8 RSR was made? I thought the 2.8 was a 74 car? If it is a factory replacement what does that actually mean? Was it actually for the car and someone bought it to replace the tach in their car for whatever reason? I appreciate the help!

[HughH]

The RSR2.8's were 1973MY cars - the racing or M491 version of the RS2.7 with slightly larger cylinder bore (92mm instead of 90mm) giving them an engine capacity of 2806 (hence 2.8) but roughly one third more power than the RS. The last one of those built was 9113601549 built in June 1973. They were built with the silver centered gauges like the one you have there as were all model year 73 (and earlier) cars. It did not mean that they kept the stock tachos in them for long as driver or team preference may sometimes have been for a more complex one for race use (like with an engine over-rev tell tail etc).
In the 1974 model year (starting August 1973) Porsche moved to the G series big bumper cars which had "updated" interiors and gauges with a black center replacing the silver one.

That applied (in theory) across ALL cars made from then including the race cars by then were RS and RSR3.0's. As in all of these things that did not mean that those would have stayed in the car long due to driver or team preference. Here are two pictures of 74 model RS and RSR
The RS one with the untouched dash is below and has a standard S tach

this particular car is a RHD car that was Hamiltons

the next picture is of a restored RSR3.0 showing a 10,000 RPM tach

I dont know if it is original to the car BUT the important thing is to notice the black center part on both compared to the silver one on yours which is for model year 73 and earlier

All that factory replacement (or Spare) means is that it is a genuine part, but not installed brand new into a car - ie sold via the spare parts network. It would not be uncommon for tach's to be replaced in race cars and certainly that is. These parts with silver center and that serial number were made well after the one you have as spare parts.

[Concept42]

Hi Hugh - Again thanks for the help. Then if I understand you my Tach if for 73 cars or earlier even though the date code is 8/73? And it could have been used in an RS M471 or an RSR? I am sorry I do not mean to sound ignorant but I am new to the RS community and trying to understand and learn about the cars as well. Thanks again! Joe

[BOYER73S]

If it was MADE /DATED 8/73 then would never have been delivered in an original RS or RSR (Hugh confirmed final date of production for RSR)
but would look at home in one of those cars until you checked the production date.