ROW SC rev limiting rotor

Rondinone · 09-22-2004, 05:58 PM

It seems impossible to get a ROW SC rev-limiting rotor. However I read in a past thread that the turbo rotor would fit although it was set to a lower rpm (actually, the turbo guys wanted to defeat the rev-limiter so they used a standard SC rotor). I just ordered one from Pelican, and it has "7000" in large letters on the side. It seems to be the same size as the US SC rotor, and fits my distributor.

Has anybody else tried using a turbo rotor in an SC? If it works this could be a reasonable solution, for only 200 rpm loss.

ecm911 · 09-22-2004, 06:33 PM

Get post, I was wondering the same thing. PLEASE let me know if it works. Is there any other options available to put a rev limiter on a row sc?

Earl

Elombard · 09-22-2004, 07:08 PM

I had one it worked great. Did not even notice the loss of RPM. I sold the motor and rotor with it to a guy on the board (Rudy) should still be in there.

SpeedracerIndy · 08:08 PM

I have never heard of using the turbo rotor. If the distributor is the same size and spins the same way it seems like it should work. The rev limiting rotor for euro SCs is a 6800 rpm limit. As far as I know there were not any SCs that were limited above 6800. The pre 78 S's had a limit of 7000 or 7200. When I was looking for mine, I could only find it at Vertex for around $20. If you can find a part number for it, you should be able to type it into the box at the top of this page and get it from Pelican. If you need me to, I can get the part number off of mine. It is in the car, and I won't be able to get to it until tomorrow afternoon though.

Elombard · 09-23-2004, 03:50 AM

When I bought mine I believe I was told the rev limit was 6600. I never verified it - I dont recall the unit saying 7000 on it anywhere though.

I think the Turbos were limited to a lower RPM - not sure why?

ecm911 · 09-23-2004, 05:30 AM

PLEASE porsche part # would be very much appreciated.

Thanks

Earl

TerryH · TerryH's Garage

It appears the part number for the CAP is the same for the SC and turbo cars.

Does having a RoW car mean without the rev limiting rotor, we lack that protection? How are the US cars rev limited?

Elombard · 09-23-2004, 05:40 AM

I read somewhere it is in the CDI box but mine sure does not seem to work. Kinda scary to test :-)) I know the rotor worked because I ran into it a few times after I put it in.

SpeedracerIndy · 09-23-2004, 06:24 AM

For all ROW SCs, the revs are limited by a rotor. The US spec SCs have a device located behind the tachometer (or there abouts) that cuts fuel. Before I had the proper rev limiting rotor in mine, I DID test it on accident. I don't care to try it again as my tachometer swept very quickly past 7000 to what I would guess was around 9000 rpms. It happened when I shifted into second, floored it and the transmission slipped out of gear. Needless to say, I have since added the rev limiting rotor and rebuilt my transmission.

I will get the part number of my (correct) rev limiting rotor this evening when I get home from work.

SpeedracerIndy · 09-23-2004, 06:40 AM

Here are some very informative threads regarding the rev limiting rotors in SCs if you are in doubt:
Help with ROW 3.0 Ignition Parts
ROW Ivs US Spec gnition parts
SC rev limit rotor
SC Rev limiter ?
Engine over rev protection question? <-- very good

Rondinone · 09-23-2004, 08:54 AM

Well, I drove into work today and it seems fine. Started and ran well. As I said, it appears that the rotors are the same length, height, and shaft diameter. The key was also in the same place.

My '79SC manual says that the original rotor was set to 7200 rpm. 7000, if that is indeed what this limiter is set to, is fine with me.

I called Vertex and tried my best to convince the guy that they sold the original SC rotor, but he didn't buy it. Pelican said that the originals are no longer available because there aren't that many old Porsches left in Europe, and these are ROW cars.

The turbo rotor part# is: H-602-901-01. Our host stocks it. If I encounter any problems I'll post.

SpeedracerIndy · 07:13 PM

930.602.901.02 is the part number for the ROW SC rev limiter. It has a limit of 6800 rpm (stamped on it). Are you sure your turbo rotor (930.602.901.01) has a rev limit of 7000? Did you look at the number stamped on it? On the bottom side there will be a rev limit number stamped on it. Here is the one on my car showing 6800 stamped on it:

And yes, as you can see I broke the DAMN THING taking if off so now I will be looking for a new one as well. Please report back asap with the number stamped on yours. If it really is 7000 I might just give it a try instead of trying to track down the proper 6800 rpm rotor.

Rondinone · 06:12 AM

It has a 7000 stamped on it right where the 6800 is on yours. That's why I suppose that the limit is 7000. I had read elsewhere that the turbo rotors were supposed to be set to 6500. Hence my confusion.

edit: Sorry about your now broken rotor! That sucks.

Rondinone · 09-24-2004, 06:10 AM

Here's a pic I borrowed from another site. You can clearly see the 7000 stamped on the arm.

SpeedracerIndy · 09-24-2004, 06:45 AM

That is strange that the turbo rotor you bought was a 7000 rpm rotor since I thought they were limited to 6600 also. If you look at the turbo tachs though they all have a higher red line, so maybe 7000 is correct. Here is a turbo tach, it looks like the red line is about 6800:

and here is a non turbo tach:

Can you tell me exactly which rotor you got from the Pelican catalouge? I want to make sure I get the 7000 rpm one.

Rondinone · 09-24-2004, 09:07 AM

The turbo rotor part# is: H-602-901-01.