Astroman

NO!! Don't give in so easily to this often debated question.

You are not alone: there are a lot of 911 owners out there (like me) who prefer the cleaner, more classic lines of the non-spoilered cars... MANY of us have opted to run with the front and no rear spoiler combination... because of course, the front chin spoiler looks soooo good.

It's true that I may not know what I'm missing... I also used to drive the hell out of my Dad's '79 SC back in the day sans tail, so I've never known anything else. BUT, I can assure you, driving a 911 with the front/no rear combo is safe for 99.9% of the driving I'm sure you plan to do. My car feels plenty planted to me, as I've enjoyed 120+ mph speeds at tracks like Road Atlanta with total confidence.

Go with the front spoiler, you won't regret it. BTW, the car looks great. Congratulations.

phiba

When I bought my 78 SC, it already had a front spoiler and no rear one. I like how it looks, but I don't know how it affects high speed handling, except to say that up to around 90 mph, I don't notice anything strange, and I haven't had it any faster than that. Admittedly, I don't have anything to compare it to. I did get the car's Certificate of Authenticity, and it doesn't list this as a factory option. There is one odd factory option, though, that may or may not be related to the front spoiler - "Air Conditioner without Front Condenser". Having this option means there is no opening under the front bumper. Other factory options that came with the car included sport shocks and Fuch-Pirellis. On the other hand, the front spoiler may have been added by the PO, along with the stone guards.

rscredon

Intuitively with the majority of the weight in the rear end, I would think one might want to counter balance that. My car currently is void of spoilers front and rear. At higher speeds of 90+ the front end feels very light to me. I thought a front spoiler would help compensate for that. I am not an engineer, nor do I play one on TV. Are my assumptions misguided?

Jay H

From Paul Frere's book:

A G series 2.7 liter car was put on scales in a wind tunnel by Porsche for testing.

I'll quote:

"At maximum speed, total lift is reduced from 397 pounds for the car without aerodynamic aids to a mere 38 lbs with the front air dam and rear 'tray' spoiler which also reduce the drag by 2 per cent. Rear lift is reduced from 276 lb to 68 lb by the 'duck's' tail and to 29 lb with the 'tray'."

"In addition to reducing rear end lift by over 70 percent, the 'duck's tail' improves the flow of air into the engine compartment and over the tail lights, keeping the latter cleaner in bad weather. These properties were further developed by the 'tray' spoiler."

"If the a 'tray' spoiler is fitted at the rear of G or later series models, an additional hard rubber front air dam is mandatory to balance front and rear lift forces. Both are standard on the Turbo seen here on 50 series Pirelli tires."

Paul does not mention anything or publish any specs about running just a front spoiler.

Hope this helps with any decisions people need to make on spoilers.

ked

whenever I think I'm super-intuitive about Porsches, I ask myself, "what did the factory do, and why?" so, Porsche, who naturally did significant research (in lab & on track) on 911 aerodynamics throughout its design evolution (check out Leffingwell's latest 911 book that covers this issue in some detail, as well as Frere's - lot more than intuition at work), did what, exactly? well, they developed the spoilers together as a system, paired frt and rear. the early S spoiler & the RS ducktail were the first iteration, it has evolved from there. If dealers or owners did something different, or individuals think their wisdom or talent trumps the factory's, fine - but don't believe for a moment the factory would ever put a 911 on the track without matched spoilers (or none). rscredon, there are a number of reasons that steering can get light at speed on a 911, all are suspect until analyzed by an expert in the susp settings of the 911. good luck (esp to those running only one spoiler!).

JV911

+1

i'm tail-less but run a front "lip" - basically a 2" strip of black rubber on the front - feels fine to me above 80mph. although i've never driven a car with a tail so i cant compare.

congrats on the purchase...car looks great!

rscredon

Ked, reviewing my post I think you will find I wasn't taking a position of "trumping" the factory engineers. There are many after market add ons people do to increase the performance and enjoyment of their 911. The front chin spoiler is one of those. Except for track use it seems that street driving might, and I use the word might because I do no have a front spoiler, pose significant problems. After I install one I will report back with my experience.

Jay Laifman

I'm going to repeat much of what Jay and Ked said, and add a personal experience. By now you must realize that this is a science, not a fashion show. I have a 73 911 with factory front spoiler, no duck tail. I've had it for 18 years. When I first got it, it was a blast, but at high speeds, like over 90 and climbing it started getting scary light up front. I really didn't ever focus too much on it as I didn't go over 90 that often. My car was a tiny bit lower in the rear than the front. I've seen so many 911s like this that I sort of figured it was "normal." Then something like 10 years into owning it, I came across a posting that cars are supposed to be just slightly lower in front. So, on my next alignment, I had them set it just right. WOW what a difference. Remember that hand of God comment? So true and I don't even have a tail. The faster I go the firmer it feels, rock solid. I hate to think of how many years went by with it wrong!

One flip side comment, I've also seen lots of 911s that are extra high in the rear. I assume they have issues and don't even realize it - and their cars look stupid.

So, as I said above, this is a science not a fashion show. No matter what you do, go to an alignment shop that knows what they are doing and get it right. For all you know, your car is already sitting wrong (or hopefully it is just right).

Jay H

rscredon, please do post how you feel your car is at higher speed. That will be an interesting test to see what you think going from a 'clean' car to just a front spoiler. I'm not being an @ss here, just am very interested in what you observe and feel. I personally think you should add both the front and rear spoilers and/or make sure the car is aligned correctly and at the proper ride height to help the light front end feel.

I think Jay Laifman is also right in that the front spoiler issue is no longer just a cosmetic issue, but a performance issue and a safety issue. It's obvious that Porsche delivered these cars only two ways: Clean without spoilers, or with a tail (be it the original SC tail, Carrera or Turbo) AND front spoiler. To add a front spoiler just for cosmetic reasons and upset the balance of the 911 may be dangerous for some people that might take their cars to excessive speed levels.

I'm sorry for ranting and raving on this thread. However, there are many people that read these forums that never post and the archieve searches done by people are most likely extensive and are something we never know about. They should be armed with the most information possible to make informed decisions.

We've got several posts in this thread from people who have first hand experience with front spoiler only cars switching to both spoilers and noticing a huge difference (improvement) in high speed handling. There seems to be some proof that adding just a front spoiler is a negative performance and safety addition to a car based on the subjective opinions here in this thread and what one could ascertain from technical writings in several books on what Porsche observed in a wind tunnel.

[Editorial Comment On] I still can't understand why you would add something to your car that may negatively affect it's handling in certain situations. We all can't guarantee that we won't take these cars over 60 mph in straight lines...[/Editorial Comment Off]

Again, no flames or disrespect intended to anyone. Text on the internet is really flat...

Best to All,

Jay

ked

and if you review my post, you will find I wasn't suggesting you were! best of luck w/ your aero tests if you go that route. it is a challenge to be methodical & quantitative in these efforts. I would do this w/ an assistant, work up to speed in stages, and be sure to go fast enough so that the effects are clear and repeatable - I'd guess at least 120. {& just to be clear, I am NOT recommending high speed tests except w/ "a professional driver on a closed course, w/ all safety equip & procedures", etc. - for me, my own experience, comparisons, discussions w/ experts & the factory guidance is adequate.} cheers!

Jay Laifman

I'm not meaning to disagree with Jay H's comments, because I don't. I just want to point out that the long nose 911s did come with front spoilers without the duck tail, including mine, from the factory. But, he is talking about the SC-Carrera bodied cars.

rscredon

Guys, I'm not picking a fight. I have read as many positive versus negative reports of the chin only spoiler on this site and others. I am not a track guy and only on occassion in very safe situations go into higher speeds. I am willing to be wrong. And yes, I get that front and rear spoilers together is the optimum set up.

afinepoint

This is a FAQ.

Porsche designed, engineered and fitted the car for the spoiler and tail to work together. The car requires both or neither.

Any advice to the contrary is incorrect.

Reg

Naitove

I've been driving my 8 SC for 26 years with just the front spoiler (Hey- I like the way it looks). For most driving I don't notice the imbalance. However when I went 143 MPH many years ago, the car was scary light.

ked

JayL, as I best recall, the S frt spoiler was part of the factory's early attempt at addressing the swb 901 high speed handling behavior. what was it - 40 lbs of lead they put in the frt bumper as a first try? {turned out to be a combination of factors, including the lower front A arms} at the same time, aero was becoming critical in competition - well, it was always critical - just not well understood & modeled at over 100mph. remember the RSK, where they tried vertical stabilizers over the rear fenders? anyway, as the 911 became so popular for rallying, FIA class 4 & 5, and production racing around the world, they began a scientific analysis of its specific aero issues (not to mention 908/910/ 917 developments). for 911 aero, first was the little S frt spoiler. while it helped plant the nose, drivers did not like the tail's behavior at high speed (they'd go flat out for hours on a banked test track) - hmmm, steering gets heavy while rear traction gets loose...interesting. so, an aero eng and a fabricator went into the windtunnel & eventually came out w/ the ducktail & it worked. (to me) one of the most interesting things about the rear spoiler is that only a few inches or so in depth along the trailing edge acts upon the airstream. by the mid to late '70s the basics were pretty well figured out (remember how shocking the IROC Carrera rear spoiler was - and we were just getting into the ducktail!). as the Greeks said, "in all things, balance".

rscredon, no offense intended or taken. there are many people new to old 911s who weren't even born when they were built - the discussion is as much (or more!) for them as someone like yourself who clearly knows what they want and how to go about it. I'm all for modifying a car & even deviating from commonly-held norms. in doing so, I like to understand the whys, wherefores & drawbacks before I proceed. now everyone is up to speed (sorry...) now, back to chips & oil...