Greg D.

Apparently there are guys on this list savvy enough to fool the ODB II and get rid of the CEL, so my question is, hasn't someone figured out a way to fool the spoiler module ?

Weissach/Ruf want $300 for a module that raises the spoiler at 75 mph instead of 50. I remember doing a similar mod on my Corrado (that's where I caught the moving spoiler bug), but apparently nothing exists for the 993. Granted i know nothing about electronics other than how to solder, but can it be that complicated to raise that 50 mph limit to 75 or so ? Another resistor, something ? Anyone ?

914und993

I don't know, but I won a spoiler control module on ebay to experiment with. I'm no electrical engineer, and probably won't be able to figure out exactly how to change it to make it "RUF-like", but maybe it will be apparent. If not, I'll see if any owners of RUF modules will be able to look at theirs and help me figure out what changes were made.

Chip

Ron

Greg,

I was thinking the same thing. Someone with know how in the area of electronics should be able to figure out a less expensive way of doing this. I've asked how the module works and so far no one seems to know for sure. It was suggested that it may have some kind of chip in it. It was also suggested that it may have a signal that make it operate and that the signal might be some sort of pulse type signal. I don't know anything about electronics either so I might have not explained what was told to me about this pulse thing correctly. Hopefuly someone will know how it works.

Chip,

If that was the module on ebay earlier this week I bid on it too with the same intention. I did not bid any higher as the part# for the one on ebay was different than mine. Is yours the same part # as the one you bought? My car is a 97.

914und993

Ron - Thats the one. I didn't look at my own module, I just checked PET 6.0 and it was the same, except in PET there is also a second part number 964.618.121.00 listed with "/LL" under remarks. I don't know what that means or if that module would be functionally different. I guess we'll see.

Chip

Ron

Chip,

If you take that module apart to see what makes it tick send me some good pictures of the inside. I'll show them to the folks at Autometrics and see if they can figure out how it works and figure out if they can be modified to function the way we want.

Robin 993DX

The green wire on the spoiler control module, connector pin #8 provides the speed information to the spoiler module.

I am not sure what type of signal this is, voltage variation? magnetic pulse?

Someone just need to tap a scope on this line to find out what source of signal it uses in order to come up with a solution to manipulate the signal.

This is one of those projects I have had on my back burner for awhile, it hasn't been a priority for me since I have a fix tail on my 993 now.

Greg H.

I saw that module and was thinking the exact same thing you guys were. Keep us posted Chip.

It just occured to me that I can just unplug my module and keep the spoiler down all the time. Certainly don't need it at legal speeds

Greg H.

Tom W

I have a used 964 module available if anyone wants to buy an extra to experiment with.

914und993

I got that module apart. First the good news - its real easy to open up to look at the guts. The bad news is it looks to me like a dedicated microprocessor, probably counting pulses from the DME, and controlling two relays. What this implies is that modifying it to raise the spoiler at different speeds would require a change in the microcode, adding a digital divider circuit to preprocess the incoming pulses, or some other modification in the digital domain of the circuit board.

Leave it to Porsche to over-engineer the spoiler control process, instead of using an easily modified analog control circuit like the VW Corrado Greg D. refers to.

Still, if someone with a RUF spoiler control module wants to open theirs up and try to spot differences, here are pictures to compare to:
Top of circuit board
Bottom of circuit board
Oscillator xtal on board

Chip

Ron

Chip,

I don't understand all that electronics talk in the 1st paragraph of your last post. Does it mean that our modules can not be modified?

I did look at the photos you posted and from my perspective I'd say there's a lot going on inside that module; I just haven't a clue what that might be.

914und993

I think its unlikely there is a simple mod for it. My guess is RUF built a new one from scratch.

It would be interesting to see what is inside the RUF module.

Chip

Bill 993

I'm an electrical engineer, but my business is chip design. My educated guess is that the chip with the barcode label is a microcontroller with embedded software (in FLASH memory). The Siemens parts are likely solid state relays to control the spoiler. The crystal is at 4,194304 MHz. Could install a lower rate crystal, this could make the controller think the freq. pulse from DME is at a lower rate and raise the spoiler at a higher speed. Unfortunately there are some passive resistors and capacitors to filter the crystal freq., so it's likely not easy to swap it out and get to work. Another way is to divide the timing pulse from the DME to fool the unit. Dividing by two would double the speed at which the spoiler is activated.

KeithR3

I don't want sound like a party pooper...but. Is there a reason why you would want the spoiler to raise at 75 instead of 50? I like your ideas...but why?

Edward

Keith,

The simple reason, with which I agree wholeheartedly, is to stop the spoiler from going up and down in regular street traffic. Not only would this reduce wear (secondary concern for me), but it would eliminate one of those minor annoyances while driving (primary concern).

Edward

chris walrod

changing the crystal, or clock frequency, was my best guess as well.