Speed switch/RPM transducer

[Zithlord]

I have read some treads both here and on pelican, cant find a conclusive answer. I have a spare speed switch with serial number 0 336 611 006. Is this for the T or can it be used also on the S and E?

thanks
John

[jcge]

applications according to Bosch.....

http://www.automotive-tradition.de/d...0336611006.pdf

http://www.automotive-tradition.de/d...is/0336611.pdf

Regards
John

[Zithlord]

Thanks, great site for Bosch info! I looked at the two links and in the first this relay is listed for T, E and S models. In the other link it says "911 T" and "kein ersatz". Inconclusive?

John

[jcge]

John - I can't answer your question directly (conclusively) , hence I posted the links so you could see the info first hand.

I would guess that the spec sheet was written first (with its original application noted) and update at end of life. The application guide, I would assume to be the "maintained" list of product application/fittment over time. All assumptions on my part.

0 336 611 006 = OFF(1,500rpm) ON (1,610rpm) 0.5amp = PORSCHE 901 615 113 00 "dashpot" relay for emission controlled cars with carbs.
0 333 400 001 = OFF(1,350rpm) ON (1,520rpm) 2.5amp = PORSCHE 901 615 111 00 "MFI speed control" relay (supercedes Bosch 0 336 611 001)

The second part number (0 333 400 001) is listed for "Porsche 6 Zyl mit benzineinspritzung" - a fairly broad description...

The MFI stop solenoid (0 330 101 016/013) is rated at 2.1 amps....so I guess the 0 336 611 006 wouldn't have the switching capacity to handle the currnt required.

http://www.automotive-tradition.de/d...is/0333400.pdf

Another board member enquired about another (unlisted) part number...and it got me thinking...Porsche also used speed sensing relays in the ignition system as rev limiters in some early racers (eg 917 - circa 8,800rpm) You'll see reference in the above doc to the 16,100rpm relay used by NSU

Functionally, they appear to vary in the rpm set point(s) and current rating of the contacts.

Sorry I can't answer your question conclusively.

John

[gled49]

When I looked in the parts manual, it showed a relay for carbs calling it a dashpot relay. The other relay was listed for fuel injection. The dashpot was supose to hold the throttle open a little on decel to add a little air to help emissions. The fuel injection relay was supose to shut off fuel between about 2000 and 1000 on decel for the same reason but reactivate the pump so the engine wouldn't die. I don't think the relays between carb and MFI would interchange. I didn't have any relays on hand to check #'s Gordon

[jcge]

Gordon - you are correct - the 0 336 611 006 i appears to be the "dashpot" relay for the emission controlled carb cars...I've edited to post above to reflect this.
Thanks
John

[SFE]

14 years old post !

I've read (somewhere) that the Porsche Blue book finaly stated it was better to use the carburated dashpot relay (2.4T engines) in place of 911E/S speed relay (rpm transducer).

Anyone can confirm that ?

[SFE]

Found this :

[SFE]

So my understanding is you can use on a 911E or S those carburated transducer relay only if they have a green spot, am I correct ?

This question because I’ve found one of those relay NOS but without a green spot….

[SFE]

So nobody seems to be interested in that so interesting, for me, part of our MFI engines !!!