iLeo

I know Porsche only offers the wonderful looking front lip only with lower suspension, or PASM. My new Carrera will be on its way soon... well, maybe not very soon, but I'm thinking of installing the lip once the car arrives. Just wondering if Porsche doesn't offer that for this car build for a reason (i.e. aerodynamic & stability reasons). Any thoughts?

rpilot

It's a good question, but I doubt you will be able to get an accurate answer unless you are able to talk to someone in Porsche AG who can shed some light on the wind tunnel testing. But even if it does, the differences will probably be very small that I think you are splitting hairs. My guess is that they are simply offering the lip spoiler with SPASM because it is functional in that configuration to lessen the impact of front scrapes and such to the bumper.

I am sure exclusive will be able to do that directly if you ask, but i am also sure buying it separately from your dealer or suncoast and having it installed would be cheaper.

chuck911

The spoiler you're talking about comes with SPASM and includes a steeper angle on the rear spoiler to balance aerodynamics. Changing the front without the rear adjustment will result in proportionally more downforce on the front compared to the rear, with the effect increasing with increasing speed. Sure the car is probably so well engineered, and your use will probably be so far below its handling envelope, that you may never notice the difference. On the other hand, I've driven otherwise identical 911's on the track where this degree of aero equipment changes could be felt at speeds as low as 70 mph. The vast majority of cars come from manufacturers who view these things as marketing do-dads. It melds into the public mind that wings and scoops and such are purely cosmetic. On lots of cars they are. Porsche on the other hand has been refining aerodynamics longer and to a more sophisticated degree than probably any other builder. That lip is not a do-dad. Its there for a reason.

rpilot

I suppose I stand corrected....

iLeo

hmmmm... very interesting and smart answers!
I guess it's not as easy as I thought. It makes sense though, as I recently saw a similar discussion on the duck-tale spoiler and how it should only be installed with the front lip spoiler that comes with it, otherwise it might lead to some tricky traction behavior at high speed.

Thanks guys, much appreciated.

John 996 TT Cab

Years ago when the first "Ducktail" came out there was a pronouncement from Porsche Engineering that the Ducktail must not be mounted without the front spoiler lip. One of our PCA members, an Automotive Engineer concurred with this as too much downpressure on the rear could cause an un spoilered front to lift and cause control issues at high speed.

chuck911

It might help some people to consider that the kind of speed the car can easily do is actually a lot less than the takeoff air speed of lots of small aircraft. When people marvel at the superb handling of the 991 at speed, well lets just say its not all due to the suspension.

rpilot

Unless you meant to say "lot more" and misspoke, this is not entirely accurate. Rotation (takeoff) speeds of most small single engine piston aircraft are in the 55-90 knot range (~63-103 mph range), unless we have a very different definition of "small" aircraft. If you were referring to small jets, the takeoff speeds are higher but most of them less than the top speed of the 991.

I will agree with you however, that the suspension is merely a part of the whole.

Alstoy

I agree that it may cause aerodynamic handling issues at speed. However, the speed would have to be substantial. The OP did not state that he was planning to track the car. If he does not, and does not hit those speeds on regular roads, then I don't see an issue. Also, it's a $180 item that can be easily taken off, if he does track the car. Cheers.