Do spoilers work?

[rich]

How many of you have a rear deck lid spoiler?
How many of you would consider installing one?
At what speed do they start to help?
Do any of you people that race have them?
I'm not asking about one of those airplane wings.

[GWN7]

If I remember...... they help at about 150mph.

[bob174]

There's nothing scarrier in my car than when, with all four pistons screaming at 12,000 rpm, the 914 starts to lift off.

[JWest]

Spoilers don't work - man really can't fly, and the landing on the moon was really a film made in Hollywood.

I apologize - I don't know at what speed the lip spoiler on a 914 starts to have an effect.

[John Rogers]

Testing done in the past shows the rear, small decklid spoiler has little to no effect at any speed. The front on the other hand has lots of effect, mainly by causing the low pressure area under the front trunk area. You can verify this by taping lots of 6 inch pieces of ribbon all over the rear of the 914 and using a video camera to watch the rear deck lid at about 100MPH to see what they do. Make sure the top is on if that is how you plan to race it so there will be an accurate test. The 914's that have the top cut off and the windsheild removed have much less drag and rear lift than a stock bodied 914.

[rich]

What about the guy with the V8 that stated he almost swept himself off the road while passing a semi? Do you think that was caused by suspension/alignment/tire pressure? Or a lifting or lightening of the rear? Or too much pressure under the car?

John,

Have you run the same test with a "Wing"?? Do you have an opinion how effective a "Wing" might be??

Ken

[John Rogers]

Wings are good, big wings are better if they are correctly designed and not the Honda bolt on type that sit right on the deck lid. If you look at pictures of the PCA and POC winged 914s they are as wide as the body and mounted about the height of the roof so they get relative clean air to work with. Along with huge amounts of downforce they also make lots of drag so the power needed to move the car goes up as downforce goes up. Since I am vintage racing now there are no wings allowed, unless the car actually raced with one back when it was new and except for the IMSA 914s, not too many cars had any type of rear wing. If you want one, hell I'd say put it on as they do look pretty neat. Good luck.

[Zeke]

One fella did state on some post in some thread on some forum (sorry) that he noticed a difference when braking down from top speed into a slow corner that the rear spoiler helped the rear of the car track better. I suupose this would be the only time the rear of the car would be up in the air a little more than usual.

If the spoiler doesn't help because it's out of the air flow, then it doesn't hurt either for the same reason. I have one because I like it. That's the main reason I do anything.

[rich]

I think the wings are fine for a race car. I understand the clean air point. I personally don't like the look of a wing on a street car. Traveling in town and hiway speed you may as well drag anchor as far as I'm concerned. I don't really care for the non stock looking rear lid spoiler either. But I would buy one if it had a positive effect though.

[DonNewton]

That fellow that posted about the aid in 90 degree turns after a fast straight was me (I guess, as I've said that before here). The dynamics of the post was that without the rear wing (the small duck lip version), entry into turn four at Mid-Ohio at an elevated speed caused the rear of the car to become VERY light under braking (CG moves forward, front compresses, rear rises into airflow, spoiler/wing addition very, very good!). Once the rear lip was installed, I became much more stable at entry, and didn't dance around as much what with the very rough track area into T4. The largest change (for the better) I've noticed is the addition of a splitter up front. What with the relatively square aero presentation the 914 has, anything that keeps air away from the bottom of the vehicle is a big plus. Empirical data collection (whether I'm scared, really scared, or terrified) tells me that with the speeds I'm seeing at MO or Watkin's Glen, this thing really works to keep be in the scared region, with occasional jaunts into the really scared realm. Haven't been terrified since before the addition of the splitter and rear lip. Check Wayne's stuff for the front splitter and lip. They really work!

I bought a duck tail spoiler to put on the back of my car. I haven't installed it yet. There's a spot at Willow Springs that my car gets very light and I'm hoping it will help a little. If it doesn't, I still like the looks of the spoiler. I'm not ready to go with any high flying above the top wing so I'm going to take my chances with the duck tail. What I haven't decided yet is whether to install it as one piece or cut it at the trunk line and install it as three pieces. Anyone have preferences on this?

[campbellcj]

Originally posted by drew365
I bought a duck tail spoiler to put on the back of my car. I haven't installed it yet. There's a spot at Willow Springs that my car gets very light and I'm hoping it will help a little. If it doesn't, I still like the looks of the spoiler. I'm not ready to go with any high flying above the top wing so I'm going to take my chances with the duck tail. What I haven't decided yet is whether to install it as one piece or cut it at the trunk line and install it as three pieces. Anyone have preferences on this?

My car has the little "GT" lip spoiler installed in one piece. Seems to be a fine way to go; the overhang on each side doesn't bug me. Like everybody else, I doubt this spoiler does much (but hopefully some small improvement) but a full leading-edge wing would look weird on my narrow-body car, and also costs mod points with POC. I do have a pretty deep front spoiler too.

Drew - what group(s) do you drive with at Willow? Are you going to the 12/12 OpenTrackRacing event?

[dave blackburn]

I dunno' guys, I saw a ford escort with a huge wing. It sounded fast (I guess). The rims looked fast and the neon lighting was mysterious, so what gives?

[Dave at Pelican Parts]

Here's a car that has the "lip" tail installed as three pieces. It's a large image, so I'll just post the link rather than the whole picture.

Not worth the effort to my eye.

http://www.racersgroup.com/images/cars%20for%20sale/914.6/914-6rearside.JPG

--DD

[John2kx]

Rich,

Just when I thought that 100 mph pass around the 18 wheeler was forgotten, you bring it up again : )

I'm not sure of the cause but have my suspicions. Top was off, windows were down and I had OLD narrow tires (165/65s I believe).

I also had a front end vibration (prior to close call) at 62 mph. Ended up being caused by front passenger side tire being out of round by about 1/4 inch. Moved it to rear and the vibration went away. Add all these up and I think you see the dangerous position I put myself in.

I've recently upgraded to 205/55s on all four corners and it's like driving a new car. Handling is much improved (understatement) and the car feels like a giant hand is holding it to road at all times. Not to say I'll ever do the high speed "go around" of a big rig again though.

I seem to remember Brad saying that the rear spoilers were effective at 130 mph.

John

[Zeke]

Originally posted by Dave at Pelican Parts
Here's a car that has the "lip" tail installed as three pieces. It's a large image, so I'll just post the link rather than the whole picture.

Not worth the effort to my eye.

http://www.racersgroup.com/images/cars%20for%20sale/914.6/914-6rearside.JPG

--DD

Looks OK to me, but I confined the modification to the lid itself so that if I wanted to go back to stock, all I'd have to do is change the lid.

I first put a duck tail spoiler on a '61 Corvette in 1966. I got the idea from the McClarens and Chaparals of the old CamAm series. The things kinda go with the period.