Aerodynamic benefits from OEM chin / duck tail spoilers?
 

Some of the late '60s & early '70s cars being raced now as Stockers were available with factory options such as chin spoilers and duck tail spoilers (e.g. '69 Camaro Z-28, '70 Dodge T/A Challenger). I'm interested to hear if anyone has tested these styles of front and/or rear spoilers and seen any benefits either on the ET slip or improved top-end stability. Thanks - Brad

Re: Benefits from OEM chin / duck tail spoilers?
 

Absolutely Zero on our 1980 Aspen (318) R/T =
Just a nuisance and a pain to R and R and
purely cosmetic.

We used to have to run them to claim a
particular engine combo years ago that we
used to run.

You and your brother know the car (We ran it at
some of your events) = It runs High 10s and you
would not be able to tell if they were on or off
from behind the wheel.

Re: Benefits from OEM chin / duck tail spoilers?
 

I always wondered if the air deflector at the back of a wagon to help keep the back glass clean would help or hurt performance.

Re: Benefits from OEM chin / duck tail spoilers?
 

The Olds wagon is just fast enough that the deflector helps get dust off of rear window. So it does show diverting air in a forward direction.

Re: Benefits from OEM chin / duck tail spoilers?
 

First, I'm not one of the Hawks that the 1st poster believes me to be. Actually, my name is actually spelled H-a-a-k, but it's pronounced "Hawk' so sometimes that's how I list myself online. Ironically, I have a brother who lives very close to the track outside Boise, ID (he lives in Eagle), but he's a complete non-gearhead. I'm on the other side of the country, in the Washington, D.C. suburbs.

Some older articles I found on vehicle aerodynamics let me to believe that anything you could do to reduce the amount of air getting under the front of the car would be a good thing (ground clearance permitting), and could help with keeping the front end from lifting on the big end, too. What I wasn't sure of is whether the OEM-type chin spoilers were physically large enough to be functional in that respect, or were primarily cosmetic add-ons.

I know the ducktail spoilers do "something", but what exactly -- and under what conditions -- I'm not sure. I did find it interesting that all of the Drag Pak Challengers have come with a front air splitter, but only the latest generation of the supercharged 354 version now has the ducktail spoiler, as well.

Re: Benefits from OEM chin / duck tail spoilers?
 

Hurts performance by creating a vortex, which creates drag.

Re: Benefits from OEM chin / duck tail spoilers?
 

Wasn't there a discussion a while back which included first and/or second gen. Camaros trying to run the front spoiler but without the rear duck tail? Front helped while the rear hurt. Nascar shows how fractional changes on the rear makes noticeable differences in speed.

Re: Benefits from OEM chin / duck tail spoilers?
 

Just Curious if your the same BRAD Hawk that use to come by Calhoun Speed in alexandria before we closed back in 2003?

Re: Benefits from OEM chin / duck tail spoilers?
 

Yep. Hi Duane! :D

Re: Benefits from OEM chin / duck tail spoilers?
 

Back in the early 70's when our Z-28 stocker was running high 11's we tried it with out the front spoiler and the back spoiler in place lost ET and MPH, can't remember the numbers, but with the rear spoiler off and the front spoiler on there was a + 2 MPH and about a nickel quicker ET. NHRA made us put the rear spoiler back on. What really helped was putting 6 cylinder Camaro front suspension and drum brakes on it. Hid the weight we saved in the back and the 7" tires liked it.

Re: Benefits from OEM chin / duck tail spoilers?
 

I found some screenshots of an old Car Life magazine test of OEM front & rear spoilers & wings that touched on this topic. Unfortunately, I can't get the png copies I made of sections of the article to upload successfully here and I don't know what's causing the error.

The brief summary of the pertinent data was that for a '69 Camaro Z-28 tested with no OEM spoilers, front chin spoiler only, rear ducktail spoiler only, and both spoilers. The test data was taken at 65, 85 and 115 MPH intervals using equipment that at the time appeared pretty state-of-the-art, but archaic compared to what's available today. My interpretation of the graphs is as follows, with "+" indicating lift in lbs and "-" indicating downforce in lbs from the 115 MPH measurements only

No spoilers: F = +370; R = -25
Front only: F = +220; R = -30
Rear only: F = +400; R = -120
Both F&R: F = +325; R = -140

I came across some anecdotes from "way back when" that some class racers had dome similar tests on the track and found small improvements with running only the front were cancelled out by running the rear, too (just like A. Smith mentioned above), but the NHRA was being hardliners about having to run both, if the factory option package was specifically for both pieces.

What I see today looking at a couple of A & B/SA '70-71 Challengers is cars that are using these OEM add-ons aren't necessarily doing it as a set (e.g., one A/SA car has only the front chin spoilers and another B/SA car appears to have only the ducktail spoiler), so I don't know if that rule is even enforced any longer. Or maybe the Mopar options were more flexible than the Chevrolet.

I don't know if any of this is still pertinent to what's being run today, but I'm certainly curious. Thx

EDIT: It looks like the original article is posted in screenshots on this older Moparts.com thread, if you're interested in seeing more of what it involved: https://board.moparts.org/ubbthreads...unctional.html