axl911

Hi all,

I am tired of the rear spoiler going up and down 50 times when I drive. It will eventually wear out and break.

I am thinking of modifying its operations. The car is a 92 C2 (with one spoiler controller box under the dash). From the info I've gathered. Pin 12 is the speed sensor and assuming pin 5 is ground. It sees 3V with ignition off, 11.5V at rest, and ~9V when the car reaches 50MPH and activating the spoiler.

Assuming the controller uses DC voltage to raise/lower the spoiler, one can tweak the voltage to pin 12 to change the speed at which the spoiler raises and lower. I can install a variable resistor in series to pin 12 and change the voltage to pin 12. This should change (lower the speed which the spoiler raises.

What are your thoughts before I do this and blow up my car.

thanks,
anthony

TMH

But... If you are concerned that it is already going up and down too often, which will ultimately cause it to wear out, then why would you want to "lower the speed [at] which the spoiler raises." This would cause it to go up and down even more often...

Tom

axl911

Not really, if I can lower the voltage enough the car will think it's moving 50mph all the time. So it will raise the spoiler when the car is moving and won't lower the spoiler until I shut the car off. (Hoping the circuitry is smart enough that it will lower the spoiler when the ignition is off).

Otherwise, to raise the point where the spoiler raises I just have to add voltage to the lead going to pin 12. But that is a bit harder due to voltage signal, grounding, etc.

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anthony

springer3

Whoa!

I have a 1992 C2, and I reverse engineered the spoiler controller to fix a problem with it. I posted a thread on the topic.

I have slept since I did this, and don't recall all the details. However, I do recall that the pulse signal from the speedo is what tells the spoiler control how fast the car is going. The reason you see the voltage change is that the pulse frequency is changing, and is fooling your DC voltmeter. Look at the speed signal with an oscilloscope, and you will see the the true speed signal. BTY, that signal goes to the engine controls, and you risk damaging much more than the spoiler if you start putting funny loads or signals on that lead.

I too would like to change the operation, as it does seem to raise and lower a lot in Atlanta city traffic. I did look for a method to revise the speed at which the spoiler extends. There are no internal adjustments, in the spoiler amp, and for obvious reasons you can't play with the speed signal without risking adverse effects elsewhere. The only option is to remove the speed signal, and operate manually, or build a digital divider to modify the pulse speed going to the spoiler amp.

My conclusion was to leave the thing alone. If you investigate further, please post the results. I may eventually get to this, but I have time only for basic maintenance until work calms down.

Good luck!

C4TT

Why not just keep the bloody thing in "up" mode?

axl911

I'd like to keep it in the "up" mode, but in my commute anywhere, the thing goes up and down 50 times since everyone drives 50mph here in Texas.

How much does a used controller cost?

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anthony

HunterWare

Another issue is that the spoiler controller does not put down the spoiler on power off...

914und993

I wonder if the 993 spoiler controller would be a drop-in substitute? With the 993, if you manually raise the spoiler before the speed trigger raises it, it will stay up until you lower it manually, or you turn off the ignition, restart the car, and exceed spoiler trigger speed - after which it will act normally.

I'm in the habit of raising mine as I leave the garage to save wear and tear on the motor and spoiler wall.

Chip

maverick

I'm curious how many people have had a problem with the spoiler failing? I sold my '91 C2 with 80K miles and it worked like a charm. If you use the manual control to raise it, does it still come down each time you stop? I seem to recall mine stayed up if I put it manually until I shut the car down.
Maverick

pzull

I have deactivated the auto speed activated action and installed a one-touch power window relay so that manual raising and lowering of the spoiler is a simple short button press rather than holding down and counting "1,000...2,000..."

In stock configuration, If you hold down too long it may eventually burn out the motor if you hold it too short the spoiler wont be in the right position. So the "deactivate speed control *** one touch manual control" mod is highly recommended from a satisfied user.

Oh if you're wondering why my spoiler manual control is a button it's because mine's an 89 which have the switch originally in the engine compartment so I had to run the wires from the rear to the dash and used the sunroof button as the activator. I have no sunroof. BTW my windows are also one touch activation not press and hold.

axl911

I want to modify mine in such a way that once you reached 50 mph, the spoiler raises. It only lowers the spoiler when you shut the car off. No need to go up and down, up and down, up and down, up and down, up and down at every stop light.

The best way I can think of is to send a 9v signal to pin 12. Then send 11.5V after the car is shut off.

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anthony

Phil Raby

Does it really go up and down 50 times on a typical drive? I doubt it! Personally, I wouldn't worry about the mechanism failing - it generally seems to be a reliable system and does what it's supposed to, so why mess with it?

Cheers

johnfm

I have to agree with Phil. I have 100k miles on mine & no rear spoiler failure. If you search the archives, you won't find too many 'rear spoiler failures'.

Admit it - you just like tinkering!!

Christer

I might stop driving my car in case it wears out. I have already installed an office chair like Phil's instead of my drivers seat because I think that it might wear out sometime soon. I have converted my car to hovercraft operation because that way I don't get any tyrewear. I have also taken out the windscreen because I don't want stonechips. Have I missed anything?

Phil Raby

Keep your speed below 50mph so that the rear spoiler doesn't deploy, and you should be just fine.