911vet

When I add a whale tail, do I need to upgrade my front spoiler? See avatar for current chin spoiler - has no rubber lip.

I'm concerned about too much front end lift at track speeds.

Yes? No? Thoughts??

I haven't settled on which tail to get, but it will be whale style (not duck).

rusnak

The section of Paul Frere's book "911 Story" that deal with Porsche's windtunnel testing and aerodynamic developments led me to want the Carrera tail. When you look at the data, it becomes quite compelling. According to Frere, the chin spoiler is necessary when the tail is added. The two working together have the "happy" effect of reducing lift in proportionate amounts equal to the front/rear weight distribution. An interesting note is what happens in strong cross winds. Apparently a strong cross wind will cancel out the downforce of the front hood, inducing front end lift. This could be interesting if it happens in the middle of a fast turn.

race911

What's the overall point? In practical terms, is a couple hundred bucks a make-or-break? I've run practically all variations when I ran torsion bar cars, and really never could tell a difference (seat of pants, or on the clock). My preferred setup with my '79 was the 3.2 Carerra tail and rubber front lip. But I also remember running my '74 flared car with a 3.3 930 wing and stock front bumper (no lip) for a few events when I ripped my IROC nose to pieces.

911vet

No, money isn't the only issue.

To be honest, I want the tail for aesthetics more than function. But I don't want to add downforce to the rear and lighten the front if it's going to make me unstable at 130mph. I doubt my car will take flight like some have on the track, but obviously I could potentially lose some steering control if I set it up incorrectly.

I plan to remove the A/C when I add the tail to partially compensate for the added weight.

race911

In my experience, it's not going to make it unstable (and you're not going into a downforce situation with any stock 911 aero aids). You might have to drive through a bit of an imbalance, but that's just an acquired taste (skill?). "Compensating" by removing a/c is, well.........let's say we take passengers out that weight upwards of 200 lbs and really don't notice any difference in a DE situation. Wheel-to-wheel? Sure.

Bottom line, I'd find a decent used rubber lip for a few bucks. Ultimately I was never able to run an over 2.4L 911 without an oil cooler in the nose, so the requisite bumper/spoiler went on anyway.

911tracker85

hmmmm.

whale tail ... removing AC....

sounds like you are passing the point of no return upgrading the CAB into a track car.

good luck at MidOhio this weekend.

911vet

I've passed it, lapped it, and crossed the finish line. It's terrible.

Well, it's still not my "preference," but the cab has some subspace psychic electromagnetic field that induces large endorphine release in my brain and won't let me sell it. It's just been a really good car.

Yeah, looks like I have a winter project of removing the A/C and installing a whale tail. I wanted to keep the A/C for resale value, but what's the point? Also, it doesn't work to defog my windows so it's useless.

YIPPEEE!! Friday is a lapping day and I'm very excited. I went to Gingerman a few weeks ago and learned sooooo much. Can't wait to put it to work at MO.

theiceman

short answer , add the rubber lip .. I like the Carrera tail on the Narrow body cars, leave the Turbo tail for the turbo fat assed cars ..

911vet

I didn't realize the turbo tail was wider. OK, I'll try to stick with a Carrera tail.

I like the RS America and IROC tails but I'm not sure they would look right with my very "classic" looking car. There's lots of black rubber trim on the car and none on the RS tail.

Good source for the front chin rubber?

Anyone got a tail for sale?

I don't think a duck would look right on a Cabriolet. Any thoughts?

theiceman

the tail I don't think is any wider but because of it's sheer girth it just doesn't look right on our style of car .. the Carrera tail is much more elegant .....

I was following a Carrera the other day with the Turbo tail the other day and it just looked out of proportion .. of course to each his ( or her ) own . take a look at both examples in person ...

Amber Gramps

Porsche Gods, please forgive me for I know not what I've done:

http://www.showcars-bodyparts.com/porsche911.html

TroyN

I think the duck would look cool on your car. Looks great on the Targa, which has similar blocky lines with the top up.

911tracker85

I like the subtle duck tail look on Ed's targa. imitation is the most sincere form of flattery..... but spoilers are not in my immediate future.

I find it interesting most targas and cabs I see on the street dont have spoilers, where almost all coupes have them. I suspect targas/cabs were bought by people who are more included for open top cruising.

my interest in a duck tail is mainly visual. and when I get to that point, a set of fiberglass front/rear RS bumpers to go with the duck tail to complete the 'look'. that and removing the AC will take off a lot of weight.

I suspect at the speed our NA old 911s run at the track I don't think spoilers are very critical for performance. at least not the stock kinds of spoilers. even though we may hit 120+ at the end of a straight, our cars are not at that speed for long and we'll have braked down to speeds as we turn in at which the effect of stock spoilers is probably trivial. of course I have never been to any of the long / fast tracks where you carry more speed more of the time.

if we lived where we could run at 100+ speeds on the open road, another issue, or if you go to ground scarping front splitters and hugh wings...

reminds me of riding in friend's '69 hemi GTX in my youth. he had it up to about 120+ on the expressway. suddenly realize there is so much lift on the front he almost ran off the outside of a turn. I was convinced he turned the front tires so far they turned the car by acting like a rudder in the air flow.

911vet

Doug: thanks for the link.

Not to worry, I don't plan to put on any flares, 964 bumpers, or bi-wing spoilers (though, that would fit with my car's Red Baron persona).

911vet

911Tracker: I would get the duck tail if I had a Targa. Ed has proved how good that looks. I'm not sure about it on a Cabriolet, and I haven't been able to find examples.

I'm not considering this for performance enhancement. It's pure aesthetics... to give the Cab a little more aggressive appearance. I'm self-conscious when I'm with the Coupes I guess. And I spent the weekend watching the automatic spoilers lift up on the new cars. I was jealous

Who knows... I'll probably end up spending the money on new t-bars and bushings instead It would certainly make more sense.