J-McDonald

I recently spoke with the principal of a bodyshop that does lots of Porsche work, who said that, in the early '90s, Porsche sold a kit to convert a 964 C2/C4 from the active wing to the RS America wing. According to the guy, the kit consisted of a factory RSA wing, RSA decklid, RSA hinges, upgraded decklid shocks and a plug for the wire lead to the wing motor. The plug basically performs the function described by Tom Sharpes and John56 in their posts (i.e., "jumpering" the connection to fool the car's sensors into thinking that the active wing is always up).

Although I'll be using my factory 964 decklid and an MA Shaw replica RSA wing, I'd like to use this factory plug, rather than making a part to jumper the connection. Unfortunately, the two Porsche dealers that I've contacted have both confirmed that they don't have the kit in their parts books. They also noted, however, that the parts books are periodically updated and it's entirely possible that Porsche stopped producing the kit.

My question for Adrian (and anyone else) is whether it can be confirmed that the RS America kit actually exists(ed) and, if so, if the component parts (especially the plug) are still available.

One more question: the Porsche parts guy said that the 964 "turbo" decklid shocks have the same part number as the "regular" C2/C4 decklid shocks. Can anyone confirm this? If this is the case, my decklid shocks (which were replaced earlier this year with new Porsche parts) should hold up my decklid with the RSA replica wing, correct?

Thanks very much for your replies.

Kevin

J-
You can purchase the RS America wing and hinges. However, why bother with fooling the wing actuated brain. Just remove it, RSA do not have it, it is located under the passenger side dash, close to the center consule, right next to the airbag brain. The decklid shocks that you have will work fine with the new wing. It is very light.

Kevin

Also,to finish off the conversion, you need to purchase the coin tray or package box that goes in the place of the wing activation switch, #964 552 157 00

Adrian

Dear J,
Firstly the addition of the RSA wing will increase your weight by 10kgs. An aftermarket version may be heavier. Data provided by Porsche Engineering by the way.
Yes there was kit for this conversion. It "WAS" available from TEquipment. It does not have a part number as such. No it is not contained in the part catalogue either. I do not know why. These kits are no longer available from dealers. The only source for such kits now "maybe" Porsche Zentrum Stuttgart or from FVD. www.FVD.de might be worth a try. I very much doubt that Porsche would sell just one part from a kit. I will be honest and say that your chances of getting such things border on null, zero, zip.
The shocks are the same part number. I just hope they are still available. Lot of 993 parts now being used to supercede 964 parts.
Location of the equipment used for the retractable rear spoiler depends on model year. The statement by Kevin only applies to 1991 models and up. The 1989 and 1990 models are very different. You have to be very careful in this area. Fooling the warn system is better. Of course if you have a 1989 C4 you do not have a spoiler activation switch.
Ciao,
Adrian
911C4

Kevin

Adrian:

I understand your concept regarding fooling the warn system, you don't support that concept from 91 & up do you?

Adrian

Dear Kevin,
You can fool the system for all models up to 1998 model year 993s. It will work on a 1991 C2 as well. The 1991 models have less components in the system as compared to 1989 and 1990 model years and the warning speed comes from the right rear wheel speed sensor instead of the now removed pulse speed sensor but the principle remains the same,
Ciao,
Adrian
911C4

PS: the reason I believe fooling the system is better is because it is easily reversable and easily discovered by the next buyer. Disabling of systems can result in some problems which we have seen before. It is also much easier. I have other reasons but not worth discussing here because it is a little complicated.

Kevin

Adrian;

I agree with you regarding the earlier years. However on 91> the factory choose not to install the brain. I think that this the most logical decision for the later cars. Why have another lame electrical circuit? I would also question what the factory did on the Carrera RS with fixed wings? I would lean toward what they did with the RSA.

phil@tech9

Adrian,

As far as I can recall the speed sensor trigger for the spoiler is taken from the front left wheel speed sensor.

I'm interested in the right rear theory ?

J-McDonald

Thanks for the info guys. I guess that I'll jumper it (like everyone else). (I'm very leery of removing factory electronics from the car.)

I'm surprised that the car with the RSA wing will be heavier than with the active wing and motor. (I thought that one of the main reasons for putting the fixed wing on the RSA was to *reduce* the car's weight, although I imagine that increased downforce at speed also probably played a role).

As for aftermarket tail being heavier than factory, I think that the reverse is probably true, because the aftermarket tail is all fiberglass, while the factory RSA wing has a (presumably heavier) rubber edge.

Kevin -- thanks for the tip about the coin tray (to replace the wing switch). I thought briefly about keeping the switch, but having the mechanic rewire it to operate the convertible top (instead of the awkward underdash switch that presently operates the convertible top). On reflection, though, I'll probably just order the coin tray and have it installed.

Adrian

The spoiler control speed sensor is the right rear. Is well documented in the wiring diagrams and the maintenance manual for all models which I have. If you care to look at the ABS control unit you will see four wheel speed outputs. If you follow the line from the Rear RH you will come to a box numbered J77. If you go to J77 on the appropriate wiring diagram which just happens to include the retractable spoiler you will see that this input feeds into the "auxillary rear spoiler control unit on a pre 1991 model and straight into the rear spoiler control unit on a post 1990 model. The PDAS/ABS control unit on a C4 does the same. No theories here I am afraid,
Ciao,
Adrian
911C4

PS: You may be mixing up the activation of the rear spoiler with the spoiler warn lamp which also uses a speed signal. On the post 1990 this may be provided by the front left I have to check. Certainly is not the case on pre 1991 models where this signal comes from the pulse speed sensor. Also please remember that the 964 RS may well be set up differently to the standard 964s which the vast majority of bulletin board users own.