Duck tail or not

[oldgunner]

Can anyone tell me if I will notice the effects of a ducktail or will a standard deck lid be sufficient. The car will see as many track days a year as I can get to. I have heard from several friends what the purpose of a duck tail is but none of them can agree. Do they provide down force, reduce lift or increase stability in cross winds I'm not sure your input and experience will help me decide. Thanks

[nesslar]

Rear spoiler only with a front "chin" spoiler as well...................front spoiler is OK alone, rear spoiler alone, not............disclaimer: research and learn.

[oh snap]

Heres a good image from this thread:
whaletail, teatray, ducktail

Probably should have a ducktail at minimum for regular track days

[nesslar]

Front AND rear spoilers?!? Or what?!? Very misleading post; the link is useless, too.........

[oh snap]

It is maybe not the most thorough thread on tails but addressed oldgunner's questions about downforce and if he will notice a difference. I'm not sure how its misleading but I'm willing to learn.

[Racerbvd]

I have found that it really does work, and driving ove a big bridge, at speed, being passed by a Semi (the bridge is 3 miles long and cops like to hang out on the base of it) and after adding spoilers to my 911, I found that it didn't "move" when big trucks blew by.

nesslar Rear spoiler only with a front "chin" spoiler as well...................front spoiler is OK alone, rear spoiler alone, not............disclaimer: research and learn.

Correct...

[jmh61]

I ran a ducktail on my car for two years. It has 3 performance advantages:

If it's fiberglass, it is lighter than stock.

Engine will run cooler.

It eliminates lift. I can feel the difference at 80-mph +. The back end feels more planted.

[pgeorgeson]

I am not going to get into the whole "lift" vs. "downforce" debate, but I can tell you that my car felt more stable at high speed --both in straights and corners -- with the duck tail (at highway speeds I didn't notice any difference).

[FinallyGotOne]

So to clarify Oldgunner wants to either run no tail at all or a ducktail. Assuming he already has a chin spoiler. Running a duck tail does make a diffrence. I run a tail from a 3.8RSR- in fiberglass. I did it for a few months before creating with the help of some friends on here a nice chin spoiler. There is a tremendous difference in freeway speed driving. I went from a tea tray tail and standard chin, to the yellowbird front bumper and 3.8 tail, to finally a nice 3 inch rubber chin on the yellowbird front bumper, with a 3.8 tail - MUCH better!

[Jack Olsen]

A ducktail is a spoiler. It reduces lift caused by adhesion along the 'fastback' portion of a 911.

The word 'sufficient' doesn't give us much to work with. The car will generate less lift at high speeds with a ducktail. If you add a wing, you can actually begin to produce actual downforce numbers, as opposed to merely countering some of the car's built-in lift.

Plenty of people drive and track their 911s with no aero modifications at all. The car is still an impressive performer, any way you look at it. It's certainly not a dangerous car without any spoilers on it. But it will be more stable with a front spoiler and rear ducktail, whaletail or wing.

I sometimes run with very little aero.



And sometimes with lots.



It's not a fundamentally different car with the aero stuff in place, but it's faster in high speed sweepers and a little more stable all around.

[moneymanager]

No one has mentioned that it (together with front spoiler) moves the car's center of pressure back several inches... enough to improve the car's stability in a crosswind noticeably.

[Determined]

Thanks for the information in this forum, it is interesting.

[BK911]

Originally Posted by Jack Olsen;6105619
[img

http://forums.pelicanparts.com/uploads10/09LagunaLeap1171562803.jpg[/img]

Is the RF off the ground?

[ShakinJoe]

Originally Posted by BK911

Is the RF off the ground?

Of course it is! So much for the downforce

[aldente295]

So here's a related question then. I have A/C and don't plan on removing it, but still do half a dozen track days a year.

Is there a duck tail or other wing that you can easily 'bolt on' to the standard lid (say, that replaces the rear grill), and then remove when you're not at the track?

[OttoB]

Does anyone out there produce a ducktail lid for 911 turbos, or do they each have to be custom made? I know because of space constraints with the intercooler, its not an easy proposition, but I do like them and wondering if it look ok in my 965... The one below was obviously a no-expense spared project, and other than some racing 964's (non-turbo) a while back, you don't really see them on this model range, so just want to see if I can replace the ol' whale tail...

[KTL]

Originally Posted by Jack Olsen

Plenty of people drive and track their 911s with no aero modifications at all. The car is still an impressive performer, any way you look at it. It's certainly not a dangerous car without any spoilers on it. But it will be more stable with a front spoiler and rear ducktail, whaletail or wing.

*snip*

It's not a fundamentally different car with the aero stuff in place, but it's faster in high speed sweepers and a little more stable all around.

That's a nice summary of the impacts of spoilers/no spoilers.

Others mentioned the different feel of the car with and w/out the spoilers. That's certainly understandable, but it shouldn't be construed as a spoiler-less car is significantly less capable or substantially more of a handful to drive than the spoilered car.

Not to mention, on the street, we're not at the edge of grip limits where one would perceptibly feel the entire difference created by the spoilers. Point being is that if you take a fast interchange ramp at 70 mph, the spoiler-less car is not a danger compared to the spoilered car. Even if you've got the imbalance of one without the other, be it front and no rear or vice versa, the car is still quite managable even in semi-capable hands. Feels different, a little floaty, but still managable.

[paulgtr]

how is your suspension and your tires? I think that has the most to do with how the car feels when driving fast. from when I first bought my car until now, I have gone from everything being worn out and riding in 15 x 6 with 205 all season tires and poor alignment. to a step by step replacement or improvement of bushings, tie rods, struts, sway bars, torsion bars, wheels, tires, brakes, discs, alignment and most importantly corner balancing.
I ran with a ducktail most of that time and only added a rubber front valance lip last year. now I have a RUF replica bumper.
on the highway at very illegal speeds I could feel some wandering from the front end with the ducktail and no valance. I never ventured out on track with that configuration.
make sure your suspension is right first. that will help you decide if you want or need a ducktail or not.

[Racerbvd]

Originally Posted by OttoB

Does anyone out there produce a ducktail lid for 911 turbos, or do they each have to be custom made? I know because of space constraints with the intercooler, its not an easy proposition, but I do like them and wondering if it look ok in my 965... The one below was obviously a no-expense spared project, and other than some racing 964's (non-turbo) a while back, you don't really see them on this model range, so just want to see if I can replace the ol' whale tail...

A buddy of mine (in Jax) can build you a intercooler that will fit under a duck, at a very fair price too.. This is the one he built to fit under a Carrera tail..


Here is the car..

[aston@ultrasw.c]

Originally Posted by paulgtr

how is your suspension and your tires? I think that has the most to do with how the car feels when driving fast. from when I first bought my car until now, I have gone from everything being worn out and riding in 15 x 6 with 205 all season tires and poor alignment. to a step by step replacement or improvement of bushings, tie rods, struts, sway bars, torsion bars, wheels, tires, brakes, discs, alignment and most importantly corner balancing.

X2 excellent advice!